LM7805ACT - 5V 1A Fixed LDO Regulator, TO-220 | onsemi
부품 번호: LM7805ACT ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.54 | $5.40 |
| 100 | $0.42 | $42.00 |
| 500 | $0.32 | $160.00 |
| 1,000 | $0.27 | $270.00 |
| 3,000 | $0.22 | $660.00 |
LM7805ACT 개요
A linear regulator (LDO - Low-Dropout) is a type of voltage regulator that maintains a stable, low-ripple DC output even as the input voltage varies, by dissipating the excess voltage as heat across a pass element. Within the broader system hierarchy, the LM7805ACT sits in the linear-regulator branch of the power-management IC family, and is favored over switching regulators whenever the application values noise-free output, simplicity, low BOM cost, and fast transient response over efficiency. The 78xx series is the de-facto industry baseline for 5 V, 12 V, and 15 V analog rails.
Key features include a 1 A continuous output rating (with peak inrush capability higher for short transients), ±2% output voltage tolerance (the "A" grade, versus ±4% on the non-A version), 2.0 V typical dropout at full load, internal short-circuit current limit, thermal-overload protection, and a TO-220 tab that doubles as the thermal pad. No external components are required beyond input and output bypass capacitors (typically 0.33 µF and 0.1 µF).
The device uses a vertical NPN pass transistor architecture with a bandgap reference, Zener-based trimming, and on-chip safe-operating-area compensation. The architecture is intentionally simple - it has no enable pin, no soft-start, and no power-good flag - because the 7805 was designed as a "set-and-forget" rail for analog and digital subsystems where it can be left always-on behind a master switch. Its primary limitation is dropout (cannot produce 5 V from a 5 V rail) and efficiency (Pdiss = (VIN − 5 V) × IOUT, all of which becomes heat).
Typical applications include 5 V digital logic supplies, microcontroller and sensor power, hobby/Arduino/Maker boards, USB device supplies, op-amp and ADC reference rails, replacement of legacy linear rails, and any application where a clean, low-noise, fixed 5 V rail is needed from a higher-voltage DC bus.
Design consideration: at 1 A load the LM7805ACT dissipates approximately 7 W when dropping 12 V to 5 V, which demands a heatsink rated for at least 10 °C/W or larger copper area on the TO-220 tab. Always place input/output ceramic bypass capacitors close to the pins and respect the SOA of the internal pass transistor at high VIN.
This page synthesizes live distributor pricing, parametric drop-in alternatives across onsemi, STMicroelectronics, Microchip, and TI, and practical thermal/layout design notes that go beyond what is in the manufacturer datasheet.
드롭인 대체품: LM7805ACT — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: LM7805ACT (동일 폼 팩터 및 풋프린트) — 차이점: Dropout Voltage, Input Voltage Range, Maximum Output Current, Mounting Type, Output Voltage.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MC7805ACTG
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
L7805CV
✅ 드롭인✓ 재고 있음
$0.1464 / 개
데이터시트 보기 →MC7805CTG
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MC7805BTG
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
UA7805CKCS
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LM7805ACT 최대 정격 & 전기적 특성
| Regulator Type | Linear, Fixed Positive |
| 토폴로지 | 3-terminal LDO (78xx family) |
| 출력 전압 | 5.0 V nominal |
| Output Voltage Tolerance | ±2% (A-grade) |
| 최대 출력 전류 | 1.0 A continuous |
| 입력 전압 범위 | 10 V to 35 V |
| 드롭아웃 전압 | 2.0 V typical at 1 A |
| 동작 접합 온도 | -40 °C to +125 °C |
| Internal Protection | Thermal shutdown, internal current limit, safe-area compensation |
| 패키지 | TO-220-3 (TO-220AB), through-hole, 3 pins + tab |
| Pinout | Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output (front view, tab up) |
| 실장 유형 | Through-hole (THT) |
| RoHS 상태 | Compliant |
| Lead-Free | Yes |
| MSL 레벨 | N/A (through-hole package) |
LM7805ACT 핀 구성
| 핀 1 | VIN — Input voltage (10 V to 35 V) |
| 핀 2 | GND — Ground (tab also internally connected to GND) |
| 핀 3 | VOUT — Regulated +5.0 V output |
일반적인 애플리케이션
LM7805ACT 적합 용도: 6 애플리케이션s: Microcontroller and Arduino Power Rail, Sensor and Analog 5 V Supply, USB Device and Charging Supply (5 V), Industrial 24 V Bus to 5 V Logic, Hobby and Replacement / Repair Applications, Automotive Accessory and Aftermarket 5 V Supply.
Microcontroller and Arduino Power Rail
The LM7805ACT is the canonical 5 V regulator for microcontroller boards, including Arduino Uno/Mega clones, PIC and STM32 dev boards, and standalone MCU designs. With its fixed 5 V output, ±2% tolerance, and 1 A current capability, it can power an ATmega328 plus typical peripherals (LEDs, LCD, logic-level sensors) without a heatsink at light load. The 10-35 V input range means it can be fed directly from a 9 V wall adapter, a 12 V lead-acid battery, or a 24 V industrial bus. Place 0.33 µF at VIN and 0.1 µF at VOUT close to the IC pins to suppress switching transients from upstream DC-DC stages and digital logic. Because the regulator dissipates (VIN − 5 V) × IOUT as heat, expect ~1 W at VIN = 9 V, IOUT = 250 mA - small enough for the TO-220 tab to self-dissipate.
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Sensor and Analog 5 V Supply
Precision sensors, op-amps, and ADCs benefit from the LM7805ACT's clean, low-noise linear output - no switching ripple - which preserves measurement integrity. With 5.0 V ±2% and PSRR sufficient for sensor bandwidths, it can power instrumentation amplifiers, strain gauge bridges, and 5 V op-amp rails. The fixed 5 V output is convenient for ratiometric sensors where the regulator's output also serves as the ADC reference. At modest sensor loads (typically 10-100 mA) the part dissipates < 1 W and runs cool without a heatsink. The 10-35 V input range lets a single regulator serve both 12 V and 24 V industrial systems.
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USB Device and Charging Supply (5 V)
For USB-powered devices, dongles, and simple charging circuits, the LM7805ACT can be used as a clean 5 V source from a higher-voltage battery or wall adapter. The fixed 5 V matches the USB VBUS nominal exactly, and the 1 A rating covers most USB device requirements. Unlike a switching regulator, the linear output adds no EMI near the USB data lines (DP/DN) - important for full-speed and high-speed signaling. Place a common-mode choke upstream and the 7805 downstream to combine clean power with EMI filtering. Note that the dropout prevents 5 V-to-5 V operation; this topology requires VIN ≥ 7 V.
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Industrial 24 V Bus to 5 V Logic
Factory automation, PLCs, and industrial control boards frequently need a local 5 V rail generated from a 24 V nominal bus (which can be 22-28 VDC). The LM7805ACT is rated to 35 V input, easily handling the worst-case 24 V bus plus tolerance. At 24 V in and 5 V out, dissipation at 1 A is 19 W - significant, so a heatsink rated for ≤ 5 °C/W is required. This is the textbook 78xx application: rugged, simple, fault-tolerant. The internal thermal shutdown protects the part if the heatsink falls off, and the internal current limit protects downstream shorts.
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Hobby and Replacement / Repair Applications
The LM7805ACT is the most-replaced linear regulator in hobby electronics, repair shops, and educational labs - it is the 5 V output every textbook, lab manual, and YouTube tutorial assumes. When repairing vintage equipment, retrocomputing mods, or DIY synth/guitar pedal circuits, dropping a TO-220 7805 into a 3-pin 78xx footprint gives a known-good 5 V rail in seconds. It is also a popular "reference rail" on breadboard power supplies, bench supplies, and bench-top prototyping kits. With its ±2% A-grade tolerance, the ACT version is preferred over the cheaper CT (±4%) for analog work where 5.0 V accuracy matters.
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Automotive Accessory and Aftermarket 5 V Supply
In automotive 12 V battery systems, the LM7805ACT can supply 5 V to aftermarket accessories, dashcams, GPS units, lighting controllers, and telematics modules. The 10-35 V input range covers the full automotive transient envelope (cold-crank to load-dump) within operating limits. At 13.8 V VIN, 5 V VOUT, and 500 mA IOUT, dissipation is 4.4 W - manageable with a small clip-on heatsink. For full AEC-Q100 automotive qualification, designers should instead choose an automotive-grade equivalent such as the LM7805-Q1; the LM7805ACT is appropriate for non-safety accessory loads.
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추천 제품 요약
엔지니어링 참조 데이터: LM7805ACT — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MC7805ACTG | MC7805CTG | MC7805BTG | L7805CV | UA7805CKCS |
|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | onsemi | STMicroelectronics | Texas Instruments |
| Package | TO-220-3 (TO-220AB) | TO-220-3 - same | TO-220-3 - same | TO-220-3 - same | TO-220-3 - same | TO-220-3 - same |
| Output Voltage | 5.0 V | 5.0 V | 5.0 V | 5.0 V | 5.0 V | 5.0 V |
| Output Voltage Tolerance | ±2% (A-grade) | ±2% (A-grade) | ±4% (non-A) | ±4% (B-grade) | ±2% | ±2% |
| Maximum Output Current | 1.0 A | 1.0 A | 1.0 A | 1.0 A | 1.0 A | 1.0 A |
| Input Voltage Range | 10 V to 35 V | 10 V to 35 V | 10 V to 35 V | 10 V to 35 V | 10 V to 35 V | 10 V to 35 V |
| Dropout Voltage (typ at 1 A) | 2.0 V | 2.0 V | 2.0 V | 2.0 V | 2.0 V | 2.0 V |
| Internal Protections | Thermal shutdown + current limit + SOA | Thermal shutdown + current limit + SOA | Thermal shutdown + current limit + SOA | Thermal shutdown + current limit + SOA | Thermal shutdown + current limit + SOA | Thermal shutdown + current limit + SOA |
주요 차별점
- A-grade ±2% output tolerance vs ±4% on standard grade (vs MC7805CTG)
- Standard 78xx pinout enables drop-in replacement across brands (vs L7805CV (ST))
- Higher peak current capability than 78L/M variants (vs MC78M05 (500 mA version))
설계 노트
Estimated: at VIN = 12 V, VOUT = 5 V, IOUT = 1 A, the LM7805ACT dissipates approximately (12 V − 5 V) × 1 A = 7 W. With the TO-220 θJA of ~50 °C/W (free air, no heatsink), the junction would rise ~350 °C above ambient - far above the 125 °C limit, triggering thermal shutdown. Required: a heatsink rated ≤ 10 °C/W, or alternatively a smaller load. Design rule: keep dissipation below ~2 W for TO-220 self-cooled operation at 25 °C ambient.
Place a 0.33 µF (or larger) bypass capacitor on VIN and a 0.1 µF bypass capacitor on VOUT as close as physically possible to the package pins (within 1-2 mm). For long input leads or battery sources, increase CIN to 1 µF or more. Although the LM78xx series is internally compensated and stable without an output capacitor in most cases, a small output capacitor (0.1 µF ceramic) improves transient response and high-frequency PSRR.
Do not assume any TO-220 3-pin part is pin-compatible with the LM7805ACT. The L4940 (low-dropout 5 V regulator) is NOT pin-compatible with the 78xx series despite both being TO-220 - its pinout is reversed (1=GND, 2=VIN, 3=VOUT). Always re-verify the pinout on the datasheet before substituting, especially when migrating to low-dropout LDOs. Also, do not operate the LM7805ACT above 35 V input even briefly - the pass transistor will exceed its VCEO rating and may fail.
Keep the ground tab connected to a copper pour on the PCB. For a through-hole TO-220, the tab is often soldered directly into a plated through-hole that connects to a top-side copper pad - this provides both mechanical anchoring and ~50% of the thermal dissipation. In designs that need to dissipate 5-10 W, add a 100 cm² copper pour on the opposite side of the PCB (acting as a heat spreader) connected to the GND tab via thermal vias.
규정 준수 정보
RoHS-compliant and lead-free per onsemi product page. Not AEC-Q100 qualified; for automotive safety applications choose an automotive-grade equivalent. Halogen-free status not stated in the provided data.
