LM7812L-TA3-T - 12V 1A Fixed LDO Regulator, TO-220 | UTC
料号： LM7812L-TA3-T ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.1193 | $0.12 |
| 10 | $0.1135 | $1.14 |
| 100 | $0.0985 | $9.85 |
| 500 | $0.085 | $42.50 |
| 1,000 | $0.074 | $74.00 |
| 3,000 | $0.0655 | $196.50 |
LM7812L-TA3-T 概述
A linear regulator - and the 78xx family specifically - is a type of power-management IC that drops a higher DC input voltage down to a fixed, regulated lower DC output voltage using a pass transistor and on-chip bandgap reference. In the broader system hierarchy, the LM7812 sits below switching converters in efficiency but excels in simplicity, low noise, and zero EMI, which is why it remains a default choice for analog rails, op-amp supplies, relay coils, fan drivers, and microcontroller peripheral power.
Key specifications include a typical output voltage of 12V (regulated to within approximately +/-4% across line, load, and temperature), 1A continuous output current, a quiescent current of 8 mA, ripple rejection of 72 dB at 120 Hz, and an output noise floor of approximately 75 uV. The TO-220 package provides a tab that can be soldered or clipped to a PCB copper pour or external heatsink, supporting reliable operation at the upper end of the input-voltage and load-current range.
The regulator uses a series NPN pass element with on-chip bandgap reference and error amplifier, providing closed-loop regulation without external feedback components. Its 72 dB ripple rejection at 120 Hz effectively attenuates rectified mains hum and downstream switching noise from upstream converters.
Typical applications include 12V power rails for op-amps, relays, fans, LED drivers, motor drivers, microcontroller peripherals, and hobby robotics. The wide input range also supports industrial 24V systems with adequate headroom and 12V battery-powered equipment such as lead-acid battery stacks.
When designing with this device, calculate power dissipation as (VIN - VOUT) x IOUT and ensure the TO-220 tab is heatsinked when dissipation exceeds approximately 1.5W. A minimum 0.33 uF input capacitor and 0.1 uF output capacitor are recommended for stability, per the UTC datasheet.
This page synthesizes distributor pricing, drop-in alternatives across multiple manufacturers, and practical design notes not found in the standalone manufacturer datasheet, enabling engineers to source and qualify the LM7812L-TA3-T with confidence.
直接替换替代料： LM7812L-TA3-T ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： LM7812L-TA3-T （相同外形与封装尺寸） ——差异在于 Dropout Voltage, Input Voltage Range, Package, Regulator Type.
快速对比工具——选择替代料号进行并排对比：
LM7812CT
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LM7812L-TF3-T
✅ 直接替换📋 参考替代料（不在目录中）
LM7805L-TA3-T
✅ 直接替换✓ 有现货
$0.07 / 个
查看数据手册 →MC7812CTG
✅ 直接替换📋 参考替代料（不在目录中）
L7812CV
✅ 直接替换📋 参考替代料（不在目录中）
LM340-12
✅ 直接替换📋 参考替代料（不在目录中）
LM7812L-TA3-T 最大额定值与电气特性
| Regulator Type | Standard Fixed Positive Linear Regulator (LDO family) |
| Output Polarity | Positive |
| Output Voltage Type | Fixed |
| Nominal Output Voltage | 12 V |
| 最大输出电流 | 1 A |
| 输入电压范围 | 14.5 V to 35 V |
| 压差电压 | 2 V (typical) |
| 静态电流 | 8 mA (typical) |
| Ripple Rejection (PSRR) | 72 dB at 120 Hz |
| 输出噪声 | 75 uV (typical) |
| 工作结温 | -20 C to +125 C |
| 热关断 | Internal (Over-Temperature Protection) |
| 限流 | Internal Over-Current Protection |
| 封装 | TO-220, 3-pin (TA3-T = TO-220 lead-formed, lead-free, tape packing) |
| 安装类型 | Through-Hole |
| Lead Finish | Lead Free (per UTC datasheet) |
| Lifecycle Stage | Active |
| RoHS 状态 | Compliant (per JLCPCB listing) |
LM7812L-TA3-T 引脚配置
| 引脚 1 | VIN — Input voltage (14.5V to 35V) |
| 引脚 2 | GND — Ground (also connected to metal tab) |
| 引脚 3 | VOUT — Regulated 12V output |
典型应用
LM7812L-TA3-T 适用于 6 应用s: 12V Relay and Solenoid Driver Power Supply, Op-Amp and Analog Circuit 12V Rail, DC Fan and Brushless Motor Power, Microcontroller and Logic Peripheral Power, 12V LED Strip and Lighting Driver, 12V Lead-Acid Battery Charger (Float Mode).
12V Relay and Solenoid Driver Power Supply
The LM7812L-TA3-T's 12V output and 1A current capability make it well suited to power 12V automotive-style relays, solenoid valves, and switching actuators in industrial control panels. With a typical coil current of 50-200 mA per relay, the regulator comfortably drives 4-8 relay coils simultaneously while maintaining a stable 12V rail across the 24V industrial input bus. Its internal over-current protection and thermal shutdown provide robust fault tolerance when downstream wiring faults occur.
推荐
Op-Amp and Analog Circuit 12V Rail
The LM7812L-TA3-T provides a clean 12V rail for dual op-amp circuits such as the TL082, LM358, or NE5532 in audio preamplifier, instrumentation, and signal-conditioning applications. Its 72 dB ripple rejection at 120 Hz effectively attenuates rectified mains hum, while the absence of high-frequency switching noise keeps the rail quiet for low-level analog signals. The 1A current rating supports multi-op-amp circuits and small buffer stages without additional regulation.
推荐
DC Fan and Brushless Motor Power
The LM7812L-TA3-T's 1A continuous output current makes it a good fit for powering 12V DC cooling fans, small brushless motors, and PC-style PWM fans used in 3D printers, CNC machines, and electronics enclosures. The fixed 12V output allows fan operation without additional PWM drive circuitry, and the wide 14.5V-35V input range accepts 24V industrial rails or rectified 18VAC transformer outputs. A bypass capacitor on the output reduces motor commutator noise back into the rail.
推荐
Microcontroller and Logic Peripheral Power
The LM7812L-TA3-T supplies 12V to microcontroller peripheral circuitry such as RS-232 line drivers (MAX232), LCD bias generators, sensor excitation, and analog signal-conditioning front-ends in 5V MCU systems. The 12V rail provides ample headroom for op-amp dual-supply generation via ICL7660 or LT1054 charge pumps. The internal thermal protection prevents catastrophic failure during sustained overload conditions, making it reliable in unattended industrial installations.
推荐
12V LED Strip and Lighting Driver
The LM7812L-TA3-T powers 12V LED strips, automotive interior lighting, and signage modules that draw up to 1A total (approximately 5 meters of standard 5050 LED strip). The fixed 12V output matches the typical LED strip forward-voltage requirement, eliminating the need for constant-current LED drivers. Its 72 dB PSRR keeps the LED brightness steady even when upstream 24V supplies sag under transient loads, and thermal shutdown protects against short-circuit faults.
推荐
12V Lead-Acid Battery Charger (Float Mode)
The LM7812L-TA3-T can serve as a simple float charger for 12V lead-acid batteries when paired with current-limiting resistors, providing a regulated 12V rail at up to 1A. This is a low-cost charging solution for backup battery systems, emergency lighting, and small UPS applications. The thermal shutdown and current limit protect the regulator from overload during deeply discharged battery recovery. A series resistor sets the float current, while a reverse-biased Schottky diode prevents discharge through the regulator.
推荐
推荐产品汇总
工程参考数据： LM7812L-TA3-T ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LM7812CT | LM7812L-TF3-T | LM7805L-TA3-T | MC7812CTG | L7812CV | LM340-12 |
|---|---|---|---|---|---|---|---|
| Package | TO-220 (TA3-T) | TO-220 | TO-220 | TO-220 | TO-220 | TO-220 | TO-220 |
| Brand | Unisonic Technologies | Unisonic Technologies | Unisonic Technologies | Unisonic Technologies | onsemi | STMicroelectronics | Texas Instruments |
| Output Voltage | 12 V | 12 V | 12 V | 5 V | 12 V | 12 V | 12 V |
| Maximum Output Current | 1 A | 1 A | 1 A | 1 A | 1 A | 1.5 A | 1 A |
| Input Voltage Range | 14.5 V to 35 V | 14.5 V to 35 V | 14.5 V to 35 V | 7 V to 35 V | 14.5 V to 35 V | 14.5 V to 35 V | 14.5 V to 35 V |
| Dropout Voltage | 2 V (typical) | 2 V | 2 V | 2 V | 2 V | 2 V | 2 V |
| Quiescent Current | 8 mA | 8 mA | 8 mA | 8 mA | 8 mA | 8 mA | 8 mA |
| Ripple Rejection (PSRR) | 72 dB at 120 Hz | 72 dB at 120 Hz | 72 dB at 120 Hz | 72 dB at 120 Hz | 72 dB at 120 Hz | 72 dB at 120 Hz | 72 dB at 120 Hz |
| Unit Price (qty 1, USD) | $0.1193 | ~$0.12 | ~$0.12 | ~$0.12 | ~$0.45 | ~$0.60 | ~$1.20 |
关键差异点
- Lowest-cost 12V TO-220 regulator in the 78xx family at LCSC （对比 MC7812CTG (onsemi))
- Wider sourcing availability in Asia-Pacific channel （对比 L7812CV (STMicroelectronics))
- Same TO-220 footprint as TI LM340-12 with lower BOM cost （对比 LM340-12 (Texas Instruments))
设计说明
Estimated: At VIN=24V, VOUT=12V, IOUT=1A, power dissipation is (24-12)*1 = 12W. With TO-220 junction-to-ambient thermal resistance of approximately 50 C/W without heatsink, Tj rise is 600 C above ambient - clearly requiring a heatsink. As a rule of thumb, attach a TO-220 clip-on heatsink (thermal resistance 10-20 C/W) whenever dissipation exceeds 1.5W to keep Tj below 125 C. A minimum 100 sq cm of PCB copper pour also provides significant heatsinking.
Per the UTC LM78XX datasheet, place a 0.33 uF ceramic or tantalum input capacitor close to the VIN pin and a 0.1 uF ceramic output capacitor close to the VOUT pin to ensure stability. Long input leads (without input capacitance) can cause oscillation when the source impedance is high, especially with a transformer-rectified supply. For applications with long wiring or inductive loads, add a 1N4007 reverse-biased diode from VOUT to VIN to protect the regulator from reverse voltage transients.
Do not exceed 35V input voltage - the regulator will go into over-voltage stress and may trigger thermal shutdown or fail. The metal tab of the TO-220 package is internally connected to GND (pin 2); when mounting to a heatsink with thermal compound, ensure the heatsink is also grounded or use a mica/thermal pad insulator if the heatsink is at a different potential. Bypass the regulator with the recommended 0.33 uF input and 0.1 uF output capacitors even if the supply appears clean - high-frequency stability depends on local decoupling.
合规信息
RoHS compliance and lead-free status confirmed via JLCPCB listing. AEC-Q100 not applicable for this through-hole linear regulator. REACH, halogen-free, and conflict-minerals status not explicitly stated in UTC datasheet - mark as 'unknown' until verified.
