7Baggers

Allegro MicroSystems, Inc
(NASDAQ:ALGM) 

ALGM stock logo

Allegro MicroSystems, Inc. designs, develops, manufactures, and markets sensor ICs and application-specific analog power ICs for motion control and energy-efficient systems in automotive and industrial markets. Its products include magnetic sensor ICs, such as position, speed, and current sensor ICs...

Founded: 1990
CEO: Ravi Vig  
Sector: Technology
Industry: Semiconductors

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At a glance:
  • Automotive End-Market Remains the Core Growth Driver: Allegro MicroSystems is heavily levered to automotive semiconductor demand, particularly for power and sensing applications tied to electrification and advanced driver assistance systems.
  • Industrial & Automation Provide Diversification, but Can Be More Cyclical: Beyond autos, Allegro serves industrial, automation, and other end markets that can add growth and balance, though demand may fluctuate with broader manufacturing cycles.
  • Strength in Power & Magnetic Sensing Portfolio: The company’s focus on power management ICs and magnetic sensor solutions positions it for content gains in EV inverters, motor control, battery management, and current sensing.
  • Margin and Inventory Dynamics Are Key Near-Term Watch Items: Like many analog/mixed-signal chip suppliers, Allegro’s near-term performance can be influenced by customer inventory digestion, product mix, and pricing/margin normalization.
  • Execution on New Design Wins and Long Automotive Program Cycles Matters: Sustained growth depends on converting design wins into production ramps, with auto program timelines that can be long but typically offer durable, multi-year revenue streams once embedded.
Bull Thesis:
  • Dominant Position in High-Growth Automotive Electrification and ADAS: Allegro's specialized sensor and power ICs are essential components for electric vehicles (EVs, HEVs) and advanced driver-assistance systems (ADAS). The company is well-positioned to benefit from the secular shift towards vehicle electrification and automation, leading to increased content per vehicle and sustained demand.
  • Expanding Reach and Content in Industrial and Data Center Markets: Beyond its strong automotive presence, Allegro is successfully penetrating industrial automation, robotics, and data center power management markets. This diversification leverages its core sensor and power expertise to capture new growth opportunities and reduce reliance on a single sector.
  • Proprietary Technology and Strong IP Portfolio: Allegro possesses a robust portfolio of proprietary sensor and power IC technologies and patents. This intellectual property creates a competitive moat, enables high-performance solutions, and supports strong pricing power and healthy gross margins in its target markets.
  • Consistent Revenue Growth and Margin Expansion: Allegro has demonstrated a track record of consistent revenue growth, driven by strong demand in its key end markets. This growth, coupled with improving gross and operating margins due to product mix optimization, operational efficiencies, and pricing power, indicates strong financial execution.
  • Resilient Fab-Lite Manufacturing Strategy: Allegro's hybrid manufacturing model, combining internal wafer fabrication with external foundry partners, provides flexibility, cost efficiency, and supply chain resilience. This strategy allows the company to adapt to market demands, optimize production, and manage capital expenditures effectively.
Bear Thesis:
  • High Concentration Risk in the Automotive Sector: A significant portion of Allegro's revenue is derived from the automotive industry. This concentration makes the company highly susceptible to cyclical downturns in vehicle production, supply chain disruptions affecting auto OEMs, or shifts in automotive technology adoption rates that could impact demand.
  • Intense Competition and Potential Pricing Pressure: Allegro operates in a highly competitive semiconductor market, facing established larger players and emerging competitors. This intense competition could lead to pricing pressure, impacting gross margins and market share, especially in more commoditized product areas or during periods of oversupply.
  • Vulnerability to Macroeconomic Slowdowns: Demand for Allegro's products, particularly in the automotive and industrial sectors, is sensitive to overall economic conditions. A significant global or regional economic slowdown could lead to reduced capital expenditures by industrial customers and lower consumer spending on vehicles, impacting order volumes and revenue.
  • Ongoing Supply Chain Volatility and Rising Input Costs: Despite a diversified manufacturing strategy, Allegro remains exposed to potential disruptions in the broader semiconductor supply chain. This includes risks of component shortages, capacity constraints at foundries, and rising raw material or manufacturing costs, which could impact production, delivery times, and profitability.
  • High R&D Investment Requirements to Maintain Competitiveness: To stay ahead in rapidly evolving markets like automotive electrification and ADAS, Allegro must continuously invest heavily in research and development. Failure to innovate effectively or if new product introductions do not gain sufficient market traction could lead to declining market share and profitability, weighing on future earnings.
Main Competitors:
  • Texas Instruments (TI) ($TXN) (Analog ICs, Power Management, Motor Drivers), Competes directly with Allegro in a wide range of analog and mixed-signal products, including power management ICs, motor drivers, and current sense amplifiers for automotive, industrial, and consumer markets. TI's vast portfolio, manufacturing scale, and broad customer base are significant competitive factors.
  • Infineon Technologies AG ($IFNNY) (Power Semiconductors, Microcontrollers, Sensors), A major competitor in automotive and industrial semiconductors, offering strong solutions in power management, motor control ICs (especially BLDC drivers), and magnetic sensors. Infineon's deep focus on these key markets and its strong position in power electronics directly overlaps with Allegro's core business.
  • STMicroelectronics (STM) ($STM) (Motor Drivers, Power Management ICs, Sensors), Competes with Allegro in motor driver ICs (stepper, BLDC), power management solutions, and magnetic sensors for automotive, industrial, and consumer applications. ST's broad product offering, strong market presence, and integrated solutions provide significant competition.
  • Analog Devices (ADI) ($ADI) (Precision Analog, Power Management, Magnetic Sensors), Competes in high-performance analog, including current sensing, power management ICs, and some magnetic sensing technologies (e.g., AMR/GMR), particularly in industrial and automotive applications where precision, reliability, and signal integrity are critical.
Moat:
Allegro MicroSystems operates in a highly competitive semiconductor market. Its primary moat lies in its deep expertise and intellectual property in high-performance magnetic sensing (Hall-effect technology) and motor control solutions, particularly for demanding automotive and industrial applications. Allegro's application-specific ICs (ASICs) often integrate multiple functions, offering compact, reliable, and highly optimized solutions. However, it faces intense competition from larger, diversified semiconductor companies like Texas Instruments, Infineon, STMicroelectronics, and Analog Devices. These competitors possess greater R&D budgets, broader product portfolios, and often larger manufacturing scale, enabling them to offer integrated solutions or bundle products, which can challenge Allegro on price, breadth of offering, and time-to-market. Allegro differentiates itself through specialized performance, quality, and strong customer relationships in its niche markets.
Income Statements:
Quarterly
Annual
    Unit: USD2026-03-27 2025-12-26 2025-09-26 2025-06-27 2025-03-28 2024-12-27 2024-09-27 2024-06-28 2024-03-29 2023-12-29 2023-09-29 2023-06-30 2023-03-31 2022-12-23 2022-09-23 2022-06-24 2022-03-25 2021-12-24 2021-09-24 2021-06-25 2021-03-26 2020-12-25 2020-09-25 
                           
      net sales
     229,210,000 214,294,000 203,405,000  177,872,000 187,391,000 166,919,000  254,984,000 271,930,000 278,293,000  203,672,000 192,640,000 176,044,000  147,168,000 156,445,000 152,689,000  138,010,000 114,138,000 
      yoy
     28.86% 14.36% 21.86%  -30.24% -31.09% -40.02%  25.19% 41.16% 58.08%  38.39% 23.14% 15.30%  6.64% 37.07%     
      qoq
     6.96% 5.35%   -5.08% 12.26%   -6.23% -2.29%   5.73% 9.43%   -5.93% 2.46%   20.92%  
      cost of goods sold
     122,109,000 115,002,000 112,103,000  96,657,000 101,729,000 92,148,000  121,156,000 114,095,000 120,343,000  84,776,000 83,962,000 99,379,000  85,464,000 91,078,000 93,982,000  90,024,000 74,879,000 
      gross profit
     107,101,000 99,292,000 91,302,000  81,215,000 85,662,000 74,771,000  133,828,000 159,503,000 157,950,000  142,594,000 132,022,000 118,374,000  101,165,000 102,532,000 94,160,000  74,425,000 61,770,000 
      yoy
     31.87% 15.91% 22.11%  -39.31% -46.29% -52.66%  -6.15% 20.82% 33.43%  40.95% 28.76% 25.72%  35.93% 65.99%     
      qoq
     7.86% 8.75%   -5.19% 14.57%   -16.10% 0.98%   8.01% 11.53%   -1.33% 8.89%   20.49%  
      gross margin %
    NaN% 46.73% 46.33% 44.89% NaN% 45.66% 45.71% 44.79% NaN% 52.48% 58.66% 56.76% NaN% 70.01% 68.53% 67.24% NaN% 68.74% 65.54% 61.67% NaN% 53.93% 54.12% 
      operating expenses:
                           
      research and development
     52,878,000 50,891,000 46,500,000  43,317,000 43,510,000 45,204,000  44,396,000 43,428,000 42,975,000  39,593,000 35,567,000 33,857,000  30,297,000 29,590,000 29,554,000  30,999,000 25,130,000 
      selling, general and administrative
     44,649,000 42,158,000 47,542,000  37,939,000 38,085,000 40,197,000  52,746,000 43,160,000 44,229,000  37,373,000 39,117,000 69,980,000  37,963,000 34,088,000 32,064,000  67,650,000 24,238,000 
      total operating expenses
     97,527,000 93,049,000 94,042,000  81,256,000 81,595,000 85,401,000  97,142,000 86,588,000 87,204,000  76,966,000 72,184,000 103,637,000  65,560,000 63,978,000 61,918,000  98,649,000 49,368,000 
      operating income
     9,574,000 6,243,000 -2,740,000  -41,000 4,067,000 -10,630,000  36,686,000 72,915,000 70,746,000  65,628,000 59,838,000 14,737,000  35,605,000 38,554,000 32,242,000  -24,224,000 12,402,000 
      yoy
     -23451.22% 53.50% -74.22%  -100.11% -94.42% -115.03%  -44.10% 21.85% 380.06%  84.32% 55.21% -54.29%  -246.98% 210.87%     
      qoq
     53.36% -327.85%   -101.01% -138.26%   -49.69% 3.07%   9.68% 306.04%   -7.65% 19.58%   -295.32%  
      operating margin %
    NaN% 4.18% 2.91% -1.35% NaN% -0.02% 2.17% -6.37% NaN% 14.39% 26.81% 25.42% NaN% 32.22% 31.06% 8.37% NaN% 24.19% 24.64% 21.12% NaN% -17.55% 10.87% 
      other income:
                           
      interest expense
     -4,910,000 -5,730,000 -6,359,000  -7,762,000 -10,353,000 -5,377,000  -3,854,000 -758,000 -769,000  -613,000 -531,000 -120,000  -269,000      
      interest income
     114,000 159,000 234,000  388,000 420,000 494,000  857,000 850,000 843,000  360,000 467,000    -1,150,000 -345,000  -2,598,000 350,000 
      loss on change in fair value of forward repurchase contract
          -34,752,000                 
      other expense
     -4,284,000 -3,387,000 -1,128,000        -2,716,000            
      income before income taxes
     494,000 -2,715,000 -9,993,000  -7,602,000 -43,083,000 -16,573,000  36,371,000 73,071,000 68,104,000  72,091,000 59,086,000 12,248,000       11,700,000 
      income tax benefit
     -7,868,000 -9,298,000                   -30,523,000  
      net income
     8,362,000 6,583,000 -13,162,000  -6,799,000 -33,613,000 -17,613,000  33,402,000 65,671,000 60,889,000  64,551,000 50,648,000 10,283,000  32,973,000 33,223,000 27,707,000  -5,060,000 9,618,000 
      yoy
     -222.99% -119.58% -25.27%  -120.36% -151.18% -128.93%  -48.25% 29.66% 492.13%  95.77% 52.45% -62.89%  -751.64% 245.43%     
      qoq
     27.02% -150.02%   -79.77% 90.84%   -49.14% 7.85%   27.45% 392.54%   -0.75% 19.91%   -152.61%  
      net income margin %
    NaN% 3.65% 3.07% -6.47% NaN% -3.82% -17.94% -10.55% NaN% 13.10% 24.15% 21.88% NaN% 31.69% 26.29% 5.84% NaN% 22.41% 21.24% 18.15% NaN% -3.67% 8.43% 
      net income attributable to non-controlling interests
     63,000 64,000 65,000  61,000 62,000 62,000  57,000 54,000 39,000  32,000 34,000 36,000  37,000 37,000 38,000  35,000 34,000 
      net income attributable to allegro microsystems, inc.
     8,299,000 6,519,000   -6,860,000 -33,675,000 -17,675,000  33,345,000 65,617,000 60,850,000  64,519,000 50,614,000 10,247,000  32,936,000 33,186,000 27,669,000  -5,095,000 9,584,000 
      net income per common share attributable to allegro microsystems, inc.:
                           
      basic
     40 40   -40 -180 -90  170 340 320            
      diluted
     40 30   -40 -180 -90  170 340 310            
      weighted-average shares outstanding:
                           
      basic
    185,035,670,000 185,172,199,000 185,074,119,000 184,587,027,000 187,707,391,000 184,011,189,000 189,182,850,000 193,465,708,000 192,573,169,000 192,724,541,000 192,431,094,000 191,997,330,000 191,197,452 191,328,538 191,284,631 190,638,135 189,748,427 189,736,901 189,673,788 189,585,381 83,448,055 124,363,078  
      diluted
    185,035,670,000 186,208,258,000 186,305,785,000 184,587,027,000 187,707,391,000 184,011,189,000 189,182,850,000 193,465,708,000 194,674,352,000 194,570,380,000 195,100,855,000 194,991,906,000 193,688,102 193,935,908 192,639,576 192,406,276 191,811,205 192,068,222 191,676,422 191,163,074 176,416,645 124,363,078  
      income tax provision
       3,169,000  -803,000 -9,470,000 1,040,000  2,969,000 7,400,000 7,215,000  7,540,000 8,438,000 1,965,000  6,281,000 6,143,000 4,263,000   2,082,000 
      net loss attributable to allegro microsystems, inc.
       -13,227,000                    
      net loss per common share attributable to allegro microsystems, inc.:
                           
      basic
       -70                    
      diluted
       -70                    
      net sales to related party
              3,579,000   45,117,000 45,026,000 41,709,000  39,461,000 37,165,000 35,453,000  26,439,000 22,511,000 
      total net sales
         177,872,000 187,391,000   254,984,000 275,509,000 278,293,000  248,789,000 237,666,000 217,753,000  186,629,000 193,610,000 188,142,000  164,449,000 136,649,000 
      cost of goods sold to related party
              1,911,000   21,419,000 21,682,000         
      other income
         -187,000 -2,465,000 -1,060,000  2,682,000 64,000             
      change in fair value of contingent consideration
                  -2,500,000 -200,000  -2,700,000 300,000 300,000    
      foreign currency transaction gain
                 407,000 266,000 1,924,000   202,000 -254,000  -145,000 -1,318,000 
      income in earnings of equity investment
                 2,190,000 -1,029,000 -864,000  287,000 226,000 279,000  949,000 246,000 
      other
                 4,119,000 75,000 -3,429,000  3,634,000 1,534,000 48,000  -510,000 20,000 
      net income attributable to allegro microsystems, inc. per share:
                           
      basic
                 0.34 0.26 0.05  0.17 0.17 0.15  -0.04  
      diluted
                 0.33 0.26 0.05  0.17 0.17 0.14  -0.04  
      loss on debt extinguishment
                         -9,055,000  
      foreign currency transaction loss
                     -3,000      
      income before income tax provision
                     39,254,000 39,366,000 31,970,000    
      net income attributable to allegro microsystems, inc. per share
                           
      basic
                 0.34 0.26 0.05  0.17 0.17 0.15  -0.04  
      diluted
                 0.33 0.26 0.05  0.17 0.17 0.14  -0.04  
      income before income tax benefit
                         -35,583,000  
      net income attributable to allegro microsystems, inc. per share:
                           
      basic and diluted
                          0.96 
      weighted-average shares outstanding:
                           
      basic and diluted
                          10,000,000 
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2026-03-27 2025-12-26 2025-09-26 2025-06-27 2025-03-28 2024-12-27 2024-09-27 2024-06-28 2024-03-29 2023-12-29 2023-09-29 2023-06-30 2023-03-31 2022-12-23 2022-09-23 2022-06-24 2022-03-25 2021-12-24 2021-09-24 2021-06-25 2021-03-26 2020-12-25 2020-09-25 
                             
        assets
                             
        current assets:
                             
        cash and cash equivalents
      168,753,000 155,187,000 117,492,000 129,106,000 121,334,000 138,452,000 188,751,000 173,136,000 212,143,000 214,308,000 370,013,000 353,408,000 351,576,000 334,306,000 293,588,000 286,557,000 282,383,000 259,208,000 248,579,000 221,934,000 197,214,000 157,653,000 201,998,000 
        restricted cash
      6,604,000 8,212,000 9,322,000 10,273,000 9,773,000 10,510,000 10,287,000 11,041,000 10,018,000 9,427,000 8,418,000 8,913,000 7,129,000 9,822,000 9,694,000 9,715,000 7,416,000 7,497,000 7,105,000 7,698,000 6,661,000 6,520,000 6,354,000 
        trade accounts receivable
      93,248,000 99,651,000 105,770,000 89,379,000 84,598,000 83,805,000 76,985,000 63,358,000  114,324,000 118,947,000 121,506,000            
        accounts receivable - other
      21,735,000        2,703,000    1,943,000    4,144,000    1,516,000 1,373,000 2,780,000 
        inventories
      181,752,000 178,195,000 170,681,000 173,796,000 183,914,000 193,140,000 176,648,000 175,901,000 162,302,000 165,553,000 173,089,000 174,170,000 151,301,000 119,580,000 98,426,000 88,933,000 86,160,000 78,858,000 78,042,000 82,356,000 87,498,000 94,021,000 104,796,000 
        prepaid income taxes
      1,179,000 14,567,000 9,363,000 968,000 36,662,000 36,037,000 38,636,000 29,411,000 31,908,000               
        prepaid expenses and other current assets
      30,335,000 47,672,000 40,324,000 27,054,000 30,247,000 33,683,000 32,253,000 33,647,000 30,674,000 41,980,000 39,938,000 38,382,000 25,346,000 22,030,000 19,232,000 18,863,000 14,995,000 16,198,000 13,069,000 12,117,000 18,374,000 31,476,000 16,585,000 
        assets held for sale
       11,928,000 16,508,000 16,508,000 16,508,000               25,309,000 25,969,000   
        total current assets
      503,606,000 515,412,000 469,460,000 447,084,000 483,036,000 495,627,000 523,560,000 490,283,000 572,213,000 549,496,000 714,896,000 700,304,000 665,829,000 619,952,000 545,485,000 529,034,000 511,692,000 469,192,000 445,914,000 452,527,000 430,564,000 378,530,000 407,222,000 
        property, plant and equipment
      308,258,000 300,861,000 300,438,000 305,195,000 302,919,000 320,975,000 325,051,000 319,763,000 321,175,000 325,822,000 312,047,000 285,200,000 263,099,000 232,076,000 219,240,000 214,808,000 210,028,000 207,705,000 198,069,000 196,993,000 192,393,000 214,372,000 217,901,000 
        operating lease right-of-use assets
      13,587,000 16,535,000 18,035,000 20,652,000 20,849,000 21,088,000 22,343,000 20,423,000 20,374,000 21,620,000 20,804,000 20,693,000 16,866,000 14,740,000 14,002,000 15,158,000 16,049,000 15,922,000 17,054,000 17,439,000    
        deferred income tax assets
      80,221,000 76,703,000 72,955,000 73,839,000 68,528,000 65,398,000 61,839,000 59,589,000 54,496,000 79,420,000 68,385,000 58,684,000 50,359,000 46,262,000 33,786,000 25,505,000 17,967,000 20,942,000 20,134,000 20,268,000 26,972,000 23,188,000 6,861,000 
        goodwill
      203,291,000 203,492,000 203,467,000 203,328,000 202,475,000 202,101,000 203,151,000 202,292,000 202,425,000 214,709,000 27,707,000 28,048,000 27,691,000 28,230,000 28,037,000 19,953,000 20,009,000 20,043,000 20,093,000 20,118,000 20,106,000 20,249,000 20,257,000 
        intangible assets
      238,675,000 244,838,000 250,929,000 256,414,000 262,115,000 261,553,000 266,753,000 271,723,000 276,854,000 293,699,000 51,677,000 51,969,000 52,378,000 53,130,000 52,268,000 36,142,000 35,970,000 35,985,000 36,131,000 36,301,000 36,366,000 36,420,000 36,274,000 
        equity investment in related party
      22,296,000 24,978,000 28,542,000 30,874,000 31,695,000 30,914,000 30,186,000 26,270,000 26,727,000 25,974,000 25,474,000 26,980,000 27,265,000 27,968,000 25,778,000 26,807,000 27,671,000 27,456,000 27,169,000 26,943,000 26,664,000 26,657,000 25,028,000 
        related party - other assets
      15,000,000                       
        other assets
      31,241,000 39,892,000 40,502,000 51,822,000 49,344,000 44,084,000 59,234,000 54,797,000 51,651,000 48,936,000 57,384,000 54,712,000 69,230,000 52,332,000 50,893,000 53,550,000 47,609,000 48,078,000 38,687,000 26,298,000 14,613,000 12,482,000 14,779,000 
        total assets
      1,416,175,000 1,422,711,000 1,384,328,000 1,389,208,000 1,420,961,000 1,441,740,000 1,492,117,000 1,448,890,000 1,530,603,000 1,565,301,000 1,284,937,000 1,234,090,000 1,181,155,000 1,084,065,000 979,802,000 926,113,000 892,620,000 851,417,000 803,251,000 796,887,000 747,678,000 711,898,000 779,699,000 
        liabilities, non-controlling interest and stockholders’ equity
                             
        current liabilities:
                             
        trade accounts payable
      44,438,000 52,558,000 41,761,000 45,609,000 38,733,000 39,685,000 50,245,000 35,346,000 35,964,000 37,633,000 62,603,000 65,382,000 56,256,000 49,945,000 40,620,000 34,492,000 29,836,000 34,189,000 29,158,000 34,704,000 35,389,000 20,262,000 23,856,000 
        amounts due to related party
      4,794,000 4,749,000 3,263,000 2,902,000 6,535,000 2,102,000 5,546,000 4,895,000 1,626,000 3,158,000 3,041,000 6,465,000  5,659,000 4,709,000 4,704,000 5,222,000 4,051,000 3,686,000 4,095,000 2,353,000 2,078,000 1,157,000 
        accrued expenses and other current liabilities
      89,472,000 76,412,000 68,305,000 64,832,000 60,083,000 52,346,000 57,203,000 58,702,000 71,126,000 69,951,000 63,394,000 76,691,000 94,894,000 77,796,000 63,941,000 68,952,000 65,459,000 59,262,000 52,049,000 76,771,000 78,932,000 66,779,000 64,929,000 
        current portion of operating lease liabilities
      5,691,000 5,870,000 5,777,000 5,807,000 5,487,000 5,405,000 5,539,000 5,183,000 5,263,000 5,486,000 5,203,000 5,007,000 4,493,000 3,828,000 3,484,000 3,656,000 3,706,000 3,339,000 3,523,000 3,463,000    
        current portion of long-term debt
      1,530,000 1,556,000 1,553,000 1,535,000 1,423,000 1,374,000 5,475,000 1,411,000 3,929,000 3,959,000              
        total current liabilities
      145,925,000 141,145,000 120,659,000 120,685,000 112,261,000 100,912,000 124,008,000 105,537,000 117,908,000 120,187,000 134,241,000 153,545,000 165,325,000 137,228,000 112,754,000 111,804,000 104,223,000 100,841,000 88,416,000 119,033,000 116,674,000 89,119,000 122,942,000 
        long-term debt
      285,746,000 286,158,000 286,135,000 310,790,000 344,703,000 374,729,000 396,056,000 202,589,000 249,611,000 250,464,000              
        operating lease liabilities, less current portion
      12,945,000 14,607,000 15,233,000 16,952,000 16,878,000 16,595,000 17,674,000 16,045,000 16,404,000 16,321,000 16,004,000 16,383,000 13,048,000 11,358,000 10,870,000 11,893,000 12,748,000 12,907,000 13,793,000 14,231,000    
        other long-term liabilities
      15,114,000 16,387,000 16,472,000 16,524,000 16,019,000 15,078,000 15,671,000 14,877,000 14,964,000 15,103,000 11,404,000 11,397,000 10,967,000 11,485,000 11,163,000 14,056,000 15,286,000 16,830,000 19,489,000 19,244,000 19,133,000 20,861,000 21,251,000 
        total liabilities
      459,730,000 458,297,000 438,499,000 464,951,000 489,861,000 507,314,000 553,409,000 339,048,000 398,887,000 429,815,000 186,649,000 206,325,000 214,340,000 189,509,000 163,927,000 162,753,000 157,257,000 155,578,000 146,698,000 177,508,000 160,807,000 134,980,000 144,193,000 
        commitments and contingencies
                             
        stockholders’ equity:
                             
        preferred stock, 0.01 par value...
                             
        common stock, 0.01 par value...
      1,854,000 1,852,000 1,851,000 1,849,000 1,843,000 1,840,000 1,840,000 1,938,000 1,932,000 1,931,000 1,925,000 1,924,000 1,918,000 1,914,000 1,913,000 1,912,000 1,905,000 1,898,000 1,897,000 1,896,000 1,896,000 1,894,000  
        additional paid-in capital
      1,050,582,000 1,040,799,000 1,029,002,000 1,013,795,000 1,012,055,000 1,004,080,000 993,988,000 693,253,000 694,332,000 684,063,000 683,891,000 674,692,000 674,179,000 667,908,000 662,082,000 652,317,000 627,792,000 612,106,000 604,488,000 597,001,000 592,170,000 589,202,000 439,732,000 
        accumulated deficit
      -68,488,000 -52,000,000 -60,299,000 -66,818,000                    
        accumulated other comprehensive loss
      -29,201,000 -27,919,000 -26,379,000 -26,173,000 -30,752,000 -34,084,000 -26,583,000 -31,946,000 -28,841,000 -21,889,000 -25,509,000 -21,198,000 -20,784,000 -24,781,000 -33,028,000 -25,198,000 -18,448,000 -16,677,000 -15,368,000 -11,865,000 -11,865,000 -10,171,000 -14,133,000 
        equity attributable to allegro microsystems, inc.
      954,747,000 962,732,000 944,175,000 922,653,000 929,555,000 933,045,000 937,314,000 1,108,582,000 1,130,435,000 1,134,232,000 1,097,089,000 1,026,583,000 965,628,000 893,379,000 814,786,000 762,236,000 734,207,000 694,669,000 655,423,000 618,252,000 585,752,000 575,831,000 634,464,000 
        non-controlling interest
      1,698,000 1,682,000 1,654,000 1,604,000                    
        total stockholders’ equity
      956,445,000 964,414,000 945,829,000 924,257,000 931,100,000 934,426,000 938,708,000 1,109,842,000 1,131,716,000 1,135,486,000 1,098,288,000 1,027,765,000  894,556,000 815,875,000   695,839,000 656,553,000     
        total liabilities, non-controlling interest and stockholders’ equity
      1,416,175,000 1,422,711,000 1,384,328,000 1,389,208,000          1,084,065,000    851,417,000      
        current portion of related party notes receivable
             3,750,000 3,750,000    3,750,000           
        related party notes receivable, less current portion
             3,750,000 4,688,000    8,438,000           
        liabilities, non-controlling interests and stockholders’ equity
                             
        (accumulated deficit) retained earnings
          -53,591,000 -38,791,000 -31,931,000                 
        non-controlling interests
          1,545,000 1,381,000 1,394,000 1,260,000 1,281,000 1,254,000 1,199,000 1,182,000 1,187,000 1,177,000 1,089,000 1,124,000 1,156,000 1,170,000 1,130,000 1,127,000 1,119,000 1,087,000 1,042,000 
        total liabilities, non-controlling interests and stockholders’ equity
          1,420,961,000 1,441,740,000 1,492,117,000 1,448,890,000 1,530,603,000 1,565,301,000 1,284,937,000 1,234,090,000            
        accounts receivable due from related party
             39,000                
        retained earnings
             445,337,000 463,012,000 470,127,000 436,782,000 371,165,000 310,315,000 248,338,000 183,819,000 133,205,000 122,958,000 97,342,000 64,406,000 31,220,000 3,551,000  208,759,000 
        trade accounts receivable, net of provision for expected credit losses of 145 and 102 at march 29, 2024 and march 31, 2023, respectively
              118,508,000               
        trade and other accounts receivable due from related party
              207,000 154,000 741,000 175,000 13,494,000 31,070,000 32,528,000 30,109,000 27,360,000 28,305,000 23,853,000 23,657,000 23,832,000 20,153,000 16,783,000 
        current portion of related party note receivable
               3,750,000 3,750,000 3,750,000  3,750,000 3,750,000 1,875,000 1,875,000 1,406,000      
        related party note receivable, less current portion
               5,625,000 6,563,000 7,500,000  9,375,000 10,313,000 5,156,000 5,625,000 6,094,000      
        deferred income tax liabilities
               27,740,000    4,438,000 4,140,000         
        obligations due under senior secured credit facilities
                25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000  
        stockholders' equity:
                             
        trade accounts receivable, net of provision for expected credit losses of 102 and 105 at march 31, 2023 and march 25, 2022, respectively
                  111,290,000           
        liabilities, non-controlling interests and stockholders' equity
                             
        amounts due to related parties
                  9,682,000           
        total stockholders' equity
                  966,815,000   763,360,000 735,363,000   619,379,000 586,871,000 576,918,000 635,506,000 
        total liabilities, non-controlling interests and stockholders' equity
                  1,181,155,000           
        trade accounts receivable, net of provision for expected credit losses of 147 and 105 at december 23, 2022 and march 25, 2022, respectively
                   97,225,000          
        accounts receivable – other
                   2,169,000 1,598,000 1,430,000  1,485,000 1,295,000 1,613,000    
        trade accounts receivable, net of provision for expected credit losses of 189 and 105 at september 23, 2022 and march 25, 2022, respectively
                    86,669,000         
        liabilities, non-controlling interest and stockholders' equity
                             
        total liabilities, non-controlling interest and stockholders' equity
                    979,802,000 926,113,000 892,620,000  803,251,000 796,887,000 747,678,000 711,898,000 779,699,000 
        trade accounts receivable, net of provision for expected credit losses of 149 and 105 at june 24, 2022 and march 25, 2022, respectively
                     91,552,000        
        trade accounts receivable, net of provision for expected credit losses of 105 at march 25, 2022 and allowances for doubtful accounts 138 at march 26, 2021
                      87,359,000       
        trade accounts receivable, net of provision for expected credit losses of 70 at december 24, 2021 and allowance for doubtful accounts of 138 at march 26, 2021
                       76,235,000      
        trade accounts receivable, net of benefit from expected credit losses of 176 at september 24, 2021 and allowance for doubtful accounts of 138 at march 26, 2021
                        73,971,000     
        trade accounts receivable, net of benefit from expected credit losses of 773 at june 25, 2021 and allowance for doubtful accounts of 138 at march 26, 2021
                         77,843,000    
        trade accounts receivable, net of allowances for doubtful accounts of 138 and 288 at march 26, 2021 and march 27, 2020, respectively
                          69,500,000   
        current portion of related party debt
                             
        bank lines-of-credit
                            33,000,000 
        related party notes payable, less current portion
                             
        class a, 0.01 par value...
                             
        class l, 0.01 par value...
                             
        trade accounts receivable, net of allowances for doubtful accounts of 138 and 288 at december 25, 2020 and march 27, 2020, respectively
                           67,334,000  
        (accumulated deficit) / retained earnings
                           -5,094,000  
        trade accounts receivable, net of allowances for doubtful accounts of 338 and 288 at september 25, 2020 and march 27, 2020, respectively
                            57,926,000 
        related party note receivable
                            51,377,000 
        common stock:
                             
        class a, .01 par value...
                            100,000 
        class l, .01 par value...
                            6,000 
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2025-12-26 2025-09-26 2025-06-27 2024-12-27 2024-09-27 2024-06-28 2023-12-29 2023-09-29 2023-06-30 2022-12-23 2022-09-23 2022-06-24 2021-12-24 
                     
          cash flows from operating activities:
                     
          net income
        1,783,000   -58,025,000 -51,226,000 -17,613,000 159,962,000 126,560,000 60,889,000 125,482,000 60,931,000 10,283,000 93,903,000 
          adjustments to reconcile net income to net cash from operating activities:
                     
          depreciation and amortization
        49,828,000 32,827,000 16,216,000 48,578,000 32,455,000 16,458,000 49,548,000 29,353,000 14,273,000 36,705,000 24,125,000 11,918,000 36,522,000 
          amortization of deferred financing costs
        1,948,000 1,650,000 933,000 1,781,000 1,087,000 781,000 292,000 107,000 34,000 74,000 49,000 24,000 75,000 
          deferred income taxes
        -7,985,000 -4,171,000 -5,061,000 -11,546,000 -7,795,000 -4,999,000 -28,253,000 -18,134,000 -8,362,000 -28,387,000 -16,431,000 -7,784,000 -3,061,000 
          stock-based compensation
        37,263,000 24,443,000 10,762,000 32,251,000 21,663,000 10,118,000 32,839,000 21,919,000 11,042,000 51,242,000 42,340,000 34,136,000 18,647,000 
          loss on change in fair value of forward repurchase contract
           34,752,000 34,752,000         
          impairment of assets held for sale
                     
          impairment of long-lived assets
                     
          provisions for inventory and expected credit losses
        7,554,000 4,543,000 3,450,000 7,519,000 4,488,000 2,377,000 9,851,000 9,422,000 5,183,000   2,640,000  
          change in fair value of marketable securities
              3,579,000 3,579,000 3,651,000     
          other non-cash reconciling items
        305,000 159,000 -58,000 6,645,000 6,577,000         
          changes in operating assets and liabilities:
                     
          trade accounts receivable
        -15,604,000 -21,723,000 -5,332,000 34,356,000 41,417,000 55,134,000 -2,564,000 -7,645,000 -10,321,000 -5,894,000 5,520,000 -4,718,000 -6,133,000 
          accounts receivable - other
              -462,000 -369,000 -1,421,000 2,000,000 2,546,000 2,714,000 -9,000 
          inventories
        -1,273,000 9,253,000 7,233,000 -38,074,000 -18,831,000 -15,986,000 -19,909,000 -31,221,000 -27,947,000 -39,136,000 -17,328,000 -4,888,000 3,251,000 
          payment to related party
                     
          prepaid expenses and other assets
        17,699,000 26,627,000 35,965,000 -1,401,000 -15,808,000 -1,715,000 -12,623,000 -16,084,000 -8,779,000 -17,761,000 -9,470,000 -13,102,000 -11,870,000 
          trade accounts payable
        13,681,000 4,181,000 6,281,000 5,467,000 13,670,000 200,000 -9,604,000 2,695,000 18,431,000 19,553,000 8,928,000 4,075,000 2,026,000 
          due to and from related party
                     
          other changes in operating assets and liabilities
        23,942,000 14,042,000            
          net cash from operating activities
        127,355,000 81,980,000 61,618,000 41,560,000 49,743,000 34,196,000 168,951,000 96,393,000 49,663,000 145,658,000 91,804,000 36,553,000 118,558,000 
          capital expenditures
        -21,160,000 -17,044,000 -10,600,000 -34,564,000 -20,949,000 -10,977,000 -110,500,000 -76,101,000 -44,910,000 -52,025,000 -39,097,000 -14,389,000 -55,792,000 
          free cash flows
        106,195,000 64,936,000 51,018,000 6,996,000 28,794,000 23,219,000 58,451,000 20,292,000 4,753,000 93,633,000 52,707,000 22,164,000 62,766,000 
          cash flows from investing activities:
                     
          purchases of property, plant and equipment
        -21,160,000 -17,044,000 -10,600,000 -34,564,000 -20,949,000 -10,977,000 -110,500,000 -76,101,000 -44,910,000 -49,563,000 -35,220,000 -14,389,000 -55,792,000 
          purchases of intangible assets
                     
          acquisition of business, net of cash acquired and working capital adjustment
                     
          investment in debt security
                     
          sales in marketable securities
                     
          net cash from investing activities
        -21,160,000 -17,044,000 -10,600,000 -34,245,000 -20,949,000 -10,977,000 -502,444,000 -59,926,000 -34,939,000 -69,291,000 -54,948,000 -14,389,000 -50,123,000 
          cash flows from financing activities:
                     
          borrowings of 2023 term loan facility, net of deferred financing costs
                     
          repayment of 2020 term loan facility
                     
          net proceeds from 2026 refinanced term loan facility
                     
          repayment of term loan
        -60,000,000 -60,000,000 -35,000,000           
          repayments of other debt
                     
          finance lease payments
        -852,000 -538,000 -202,000 -703,000 -385,000 -145,000        
          receipts on related party notes receivable
           1,875,000 1,875,000 938,000   938,000 1,875,000 937,000   
          payments for intangible assets
        -4,000,000 -1,000,000            
          payments for taxes related to net share settlement of equity awards
        -10,354,000 -9,349,000 -8,988,000 -12,780,000 -12,297,000 -11,171,000 -24,823,000 -14,091,000 -12,422,000 -12,642,000 -9,606,000 -9,606,000  
          proceeds from issuance of common stock under employee purchase plan
                     
          repurchases of common stock
           -853,921,000 -853,805,000         
          net proceeds from issuance of common stock
           665,850,000 665,850,000         
          payments for taxes related to repurchase of common stock
        -1,713,000 -1,713,000            
          dividends paid to non-controlling interest
        -23,000 -23,000            
          payments of debt issuance costs
                     
          net cash from financing activities
        -75,032,000 -70,713,000 -44,190,000 -79,209,000 -53,292,000 -60,378,000 198,148,000 -15,767,000 -11,035,000 -16,694,000 -14,596,000 -9,137,000 -6,209,000 
          effect of exchange rate changes on cash and cash equivalents and restricted cash
        1,129,000 1,484,000 1,444,000 -1,305,000 1,375,000 -825,000 375,000 -974,000 -73,000 -5,344,000 -8,777,000 -6,554,000 604,000 
          net increase in cash and cash equivalents and restricted cash
        32,292,000  8,272,000  -23,123,000 -37,984,000 -134,970,000 19,726,000 3,616,000 54,329,000 13,483,000 6,473,000 62,830,000 
          cash and cash equivalents and restricted cash at beginning of period
        131,107,000 131,107,000 131,107,000 222,161,000 222,161,000 222,161,000 358,705,000 358,705,000 358,705,000 289,799,000 289,799,000 289,799,000 203,875,000 
          cash and cash equivalents and restricted cash at end of period:
          139,379,000 148,962,000 199,038,000 184,177,000 223,735,000 378,431,000 362,321,000 344,128,000 303,282,000 296,272,000 266,705,000 
          reconciliation of cash and cash equivalents and restricted cash:
                     
          cash and cash equivalents at beginning of period
                 282,383,000 282,383,000 282,383,000 197,214,000 
          restricted cash at beginning of period
                 7,416,000 7,416,000 7,416,000 6,661,000 
          cash and cash equivalents at end of period
                 334,306,000 293,588,000 286,557,000 259,208,000 
          restricted cash at end of period
                 9,822,000 9,694,000 9,715,000 7,497,000 
          cash and cash equivalents and restricted cash at end of period
        163,399,000 126,814,000        344,128,000 303,282,000 296,272,000 266,705,000 
          due to and from related parties
        -1,786,000 -3,272,000 -3,633,000 564,000 4,132,000 3,437,000        
          acquisition of business, net of cash acquired
           319,000   -408,119,000   -19,728,000 -19,728,000  -12,549,000 
          cash flow from financing activities:
                     
          net proceeds from refinanced term loan facility
                     
          proceeds from issuance of common stock under employee stock purchase plan
        1,910,000 1,910,000  1,987,000 1,987,000  1,899,000 1,899,000 1,899,000 1,573,000 1,573,000  1,291,000 
          net loss
         -6,579,000 -13,162,000           
          adjustments to reconcile net loss to net cash from operating activities:
                     
          net proceeds from refinanced 2023 term loan facility
           193,483,000 193,483,000         
          net decrease in cash and cash equivalents and restricted cash
         -4,293,000  -73,199,000          
          accrued expenses and other current and long-term liabilities
          8,024,000 -21,307,000 -16,838,000 -14,010,000 -20,540,000 -29,944,000 -17,112,000 5,717,000 -4,965,000 1,239,000 -9,874,000 
          change in fair value of contingent consideration
                 -2,700,000 -2,700,000   
          loans made to related party
                 -7,500,000 -7,500,000   
          repayment of 2023 term loan facility
           -75,000,000          
          sales of marketable securities
                     
          borrowings of senior secured debt, net of deferred financing costs
              245,452,000       
          repayment of other debt
              -743,000       
          loan made to affiliate
               -4,000,000      
          payment of borrowings under 2023 term loan facility
            -50,000,000 -50,000,000        
          loss on disposal of assets
             14,000 18,000 43,000  287,000 250,000  -349,000 
          proceeds from issuance of common stock under employee stock purchase plan awards
                     
          due to (from) related party
              6,817,000 6,112,000      
          proceeds from sales of property, plant and equipment
                    27,407,000 
          sales (purchases) in marketable securities
                     
          proceeds from issuance of common stock under equity award and employee purchase plan awards
                     
          proceeds from sales of marketable securities
              16,175,000 16,175,000 9,971,000     
          repayment of term loan facility
              -25,000,000       
          receipts on related party note receivable
              2,813,000 1,875,000    469,000  
          payments for debt issuance costs
              -1,450,000 -1,450,000 -1,450,000     
          gain on disposal of assets
                   -3,000  
          due to/from related parties
                10,102,000 -3,273,000 -5,681,000 -3,267,000 -2,775,000 
          loss on debt extinguishment
                     
          provisions for inventory writedowns and receivables reserves
                     
          unrealized gains on marketable securities
                    -4,482,000 
          investments in marketable securities
                    -9,189,000 
          contribution of cash balances due to divestiture of subsidiary
                     
          proceeds from initial public offering, net of underwriting discounts and other offering costs
                     
          proceeds from issuance of common stock under equity award and purchase plans awards
                     
          dividends paid
                     
          repayment of senior secured debt
                     
          repayment of unsecured credit facilities
                     
          provisions for inventory and receivables reserves
                 1,744,000 232,000   
          unrealized loss on marketable securities
                 5,000 3,458,000 3,486,000  
          supplemental disclosures of cash flow information:
                     
          noncash transactions:
                     
          property, plant and equipment purchases included in trade accounts payable
                 -2,462,000 -3,877,000   
          noncash lease liabilities arising from obtaining right-of-use assets
                 1,926,000 374,000 150,000  
          loss on contingent consideration change in fair value
                   -200,000  
          cash paid for interest
                   452,000  
          cash refunded for income taxes
                   -1,027,000  
          trade accounts payable related to property, plant and equipment
                   -2,602,000  
          amortization of debt issuance costs
                     
          provisions for inventory and credit losses/bad debt
                    4,787,000 
          related party note receivable
                    -7,500,000 
          proceeds from issuance of common stock under equity award and purchase plans less payments for taxes related to net share settlement of equity awards
                     
          capital contribution
                     
          gain on contingent consideration change in fair value
                    -2,100,000 
          (gain) loss on disposal of assets
                     
          cash paid for income taxes
                     
          changes in trade accounts payable related to property, plant and equipment
                     
          loans to cover purchase of common stock under employee stock plan
                     
          recognition of right of use assets and lease liability upon adoption of new accounting standard
                     
          provisions for inventory and bad debt
                     
          deconsolidation related to psl divestiture
                     
          non-cash transactions:
                     
          deconsolidation related to divestiture transactions