LM7805L-TA3-T - 5V 1A Fixed Positive LDO Regulator | UTC TO-220
N.º da peça: LM7805L-TA3-T ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.13 | $0,13 |
| 10 | $0.12 | $1,20 |
| 100 | $0.1 | $10,00 |
| 500 | $0.08 | $40,00 |
| 1.000 | $0.07 | $70,00 |
LM7805L-TA3-T Visão geral
What is a linear voltage regulator? A linear voltage regulator is a power management integrated circuit that maintains a constant output voltage by varying its internal pass-element resistance. Within the broader taxonomy, the LM7805L-TA3-T is a fixed-output LDO/standard linear regulator -> linear regulator -> voltage regulator -> power management IC -> semiconductor. Compared to switching regulators, linear regulators add no switching noise to the output rail and require minimal external components, at the cost of lower efficiency when VIN-VOUT is large.
Key features include built-in over-current protection (OCP) and over-temperature protection (OTP), fixed 5V ±4% output tolerance, an operating junction temperature range of -20C to +125C, and a quiescent current of approximately 8 mA. The bipolar pass transistor architecture provides robust short-circuit immunity and predictable thermal behavior under sustained load.
Technically, the LM7805L-TA3-T uses a bandgap reference and error amplifier to drive an NPN Darlington pass element, with the dropout determined by the Vce(sat) of the Darlington plus base-drive headroom. The 80 dB PSRR at 120 Hz is more than sufficient to reject the dominant ripple component from a 50/60 Hz transformer-rectifier input stage.
Typical applications include 5V logic supply rails for microcontrollers and TTL/CMOS logic, USB device power from a 12V or 24V bus, hobbyist and educational electronics, and as a post-regulator following a switching converter to clean up residual switching noise.
When designing with this part, calculate worst-case power dissipation PD = (VIN - 5V) × IOUT and verify junction temperature using θJA = 100 °C/W (free-air) or with an attached heatsink; at 12V/1A the regulator must dissipate 7W and requires a heatsink.
This page consolidates distributor pricing for the LM7805L-TA3-T, qualified drop-in 5V/1A TO-220 alternatives, and practical PCB layout notes beyond what the manufacturer datasheet alone provides.
Alternativas drop-in para LM7805L-TA3-T — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com LM7805L-TA3-T (mesmo formato e footprint) — diferindo em Package, Maximum Output Current, Mounting Type, Dropout Voltage, Input Voltage Range.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
LM7805CT/NOPB
✅ Drop-In✓ Em estoque
$0.74 / unidade
Ver ficha técnica →L7805CV
✅ Drop-In✓ Em estoque
$0.1464 / unidade
Ver ficha técnica →MC7805CTG
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LM7805CT/NOPB
✅ Drop-In✓ Em estoque
$0.74 / unidade
Ver ficha técnica →TS7805CZ
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LM7805L-TA3-T Classificações máximas e características elétricas
| Regulator Type | Standard Linear (LDO family) |
| Output Polarity | Positive |
| Output Voltage Type | Fixed |
| Tensão de saída | 5 V (nominal) |
| Output Voltage Tolerance | ±4% (4.75 V to 5.25 V) |
| Corrente máxima de saída | 1 A |
| Faixa de tensão de entrada | Up to 35 V |
| Tensão de dropout | 2 V (typical at 1 A) |
| Corrente de repouso | 8 mA (typical) |
| PSRR (Ripple Rejection) | 80 dB at 120 Hz |
| Output Noise Voltage | 40 uV (typical) |
| Temperatura de junção de operação | -20 C to +125 C |
| Protection Features | Over Current Protection, Over Temperature Protection |
| Encapsulamento | TO-220 (3-pin, through-hole) |
| Tipo de montagem | Through-Hole |
| Lead-Free / RoHS | Lead Free, ROHS compliant |
Configuração de pinos do LM7805L-TA3-T
| Pino 1 | IN — Unregulated input voltage (up to 35 V) |
| Pino 2 | GND — Common ground (also bonded to the metal tab on TA3) |
| Pino 3 | OUT — Regulated 5 V output (up to 1 A) |
Aplicações típicas
LM7805L-TA3-T é adequado para 6 aplicaçãos: Microcontroller and Logic 5V Rail, USB Device 5V Power from 12V Bus, Hobbyist and Educational Electronics Bench Supply, Post-Regulator Following a Switching Converter, Automotive and Industrial 24V Bus 5V Rail, Discrete Linear Power Supply for Audio Pre-Amp.
Microcontroller and Logic 5V Rail
The LM7805L-TA3-T is the classic 5V linear regulator for powering microcontrollers (AVR, PIC, 8051, STM32 Blue Pill variants), 74-series TTL logic, and hobby-development boards from a 7-12V DC source. The 80 dB PSRR at 120 Hz rejects transformer ripple cleanly, and the 40 uV output noise is far below any logic-noise floor, so no extra filtering is needed. The 1A output headroom also covers typical MCU plus a small display and a few indicator LEDs without exceeding the SOA. Place a 0.33 uF input cap and a 0.1 uF output cap adjacent to the pins for stability. Pair it with the ATmega328P-AU or STM32F103C8T6 for a proven 5V digital rail.
Recomendado
USB Device 5V Power from 12V Bus
Use the LM7805L-TA3-T to derive a 5V USB-device rail from a 12V or 24V system bus. At 12V input, the regulator must dissipate (12 - 5) * IOUT watts; at 500 mA load that is 3.5W, manageable with a small clip-on heatsink. For higher load currents (>700 mA) or thermally constrained enclosures, step down to a TO-220-compatible switching regulator such as the Traco TSR 1-2450 (pin-compatible, 1A, switching efficiency). The LM7805L-TA3-T remains attractive when output noise must be near-zero and Biquad (post-filter LDO) of a noisy buck is undesired.
Recomendado
Hobbyist and Educational Electronics Bench Supply
The LM7805L-TA3-T is the canonical teaching example for a linear regulator: three pins, one output, predictable thermal behavior. It is ideal for breadboard experiments, Arduino-shield prototypes, and introductory electronics labs because the TO-220 footprint is large enough for easy soldering and the part is forgiving of input-voltage variation up to 35V. The standard 7805 pinout (IN/GND/OUT) means students can swap it across thousands of project references. Combine it with the LM35 temperature sensor or the classic NE555 timer for canonical 5V lab circuits.
Recomendado
Post-Regulator Following a Switching Converter
The LM7805L-TA3-T is widely used as a post-regulator that cleans residual switching noise from an upstream buck converter. The 80 dB PSRR at 120 Hz and 40 uV output noise work together to attenuate switching-ripple harmonics before they enter noise-sensitive analog blocks. Insert the LM7805L-TA3-T between the buck output (e.g. 7V) and a precision ADC or DAC AVDD pin. The two-stage approach is a classic analog-power design pattern for audio DAC and precision instrumentation front ends, where ripple must be sub-mV even at full 1A load.
Recomendado
Automotive and Industrial 24V Bus 5V Rail
The LM7805L-TA3-T operates from inputs up to 35V, making it acceptable for 24V industrial bus systems and 24V-truck battery rails. At 24V input and 500 mA load it dissipates 9.5W, which demands a forced-air heatsink or thermal redesign - for sustained >500 mA loads a switching regulator is preferred. The LM7805L-TA3-T is, however, the right answer when the load is <300 mA and a clean 5V rail is needed, such as for a 24V-PLC indicator panel or an industrial sensor interface card. Combine with the LM25010SD/NOPB for higher-power rails on the same PCB.
Recomendado
Discrete Linear Power Supply for Audio Pre-Amp
The LM7805L-TA3-T remains a popular choice for the 5V supply of microphone pre-amplifiers and small audio-mixing boards where a clean, switching-noise-free rail is mandatory. The 40 uV output noise spec is well below the audible floor, and the 80 dB PSRR keeps 100/120 Hz mains hum rejected without additional filtering. Combine with the LM358 dual op-amp (single supply 5V) or the SSM2018 microphone pre-amp for an analog audio circuit. Use linear regulation rather than switching to avoid injecting high-frequency artifacts into the audio band.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LM7805L-TA3-T — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LM7805CT/NOPB | L7805CV | MC7805CTG | LM7805CT | TS7805CZ |
|---|---|---|---|---|---|---|
| Package | TO-220 | TO-220 - same | TO-220 - same | TO-220 - same | TO-220 - same | TO-220 - same |
| Brand | Unisonic Technologies (UTC) | Texas Instruments | STMicroelectronics | onsemi | Fairchild Semiconductor | Taiwan Semiconductor |
| Output Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Output Current (continuous) | 1 A | 1 A (1.5 A peak) | 1 A (1.5 A peak) | 1 A (2.2 A peak) | 1 A | 1 A |
| Output Voltage Tolerance | ±4% | ±2% | ±2% | ±2% | ±2% | ±2% |
| PSRR at 120 Hz | 80 dB | 73 dB (typical) | 73 dB (typical) | 73 dB (typical) | 73 dB (typical) | 73 dB (typical) |
| Max Input Voltage | 35 V | 35 V | 35 V | 35 V | 35 V | 35 V |
| Operating Junction Temperature | -20 C to +125 C | -40 C to +125 C | 0 C to +125 C | -40 C to +125 C | -40 C to +125 C | 0 C to +125 C |
| Unit Price (qty 1, approx, USD) | 0.13 | 1.50 - 2.00 | 0.65 - 0.90 | 0.45 - 0.70 | 0.40 - 0.60 | 0.20 - 0.35 |
Principais diferenciais
- Lowest unit cost in the 7805 family (vs LM7805CT/NOPB)
- Wider output tolerance for non-precision loads (vs L7805CV)
- GND-bonded tab simplifies heatsink mounting (vs MC7805CTG)
Notas de projeto
Estimated: at VIN=12V, VOUT=5V, IOUT=1A, the LM7805L-TA3-T must dissipate (12-5)*1 = 7W. The TO-220 free-air θJA is roughly 50 °C/W when mounted on a small clip-on heatsink, giving a junction temperature rise of 7*50 = 350 °C - far above the 125C limit. Designers must either use a substantial heatsink (θJA < 15 °C/W, raising TJ to about 12C above ambient + 5C for VIN variation = ~37C - safe), limit load current to <300 mA at this VIN, or place a switching pre-regulator upstream. The UTC LM7805 datasheet thermal curves assume a 2 oz copper heatsink of at least 6 cm².
Place a 0.33 uF ceramic or tantalum capacitor as close as possible to the INPUT pin and a 0.1 uF capacitor at the OUTPUT pin. For improved transient response to load steps, replace the 0.1 uF output cap with a 1-10 uF low-ESR ceramic (X5R/X7R). Long input leads (>5 cm) from a transformer-rectifier source must include the input cap to prevent regulator oscillation. The metal tab on the TA3 package variant is internally bonded to GND - mount directly to a grounded chassis heatsink with thermal compound, no insulating washer required.
Common pitfalls include: (1) exceeding the 35V absolute maximum input voltage during unloaded transformer-rectifier transients - always include a clamp or MOV; (2) using the LM7805L-TA3-T as a constant-current source by shorting OUT to a sense resistor - the part has built-in foldback current limit, not constant-current behavior; (3) expecting the regulator to start at very low input voltages - below 7V the output drops out of regulation; (4) forgetting that dropout reverses the role of IN and OUT, which can permanently damage the part. The UTC LM78XX datasheet section 'Typical Application Circuit' shows the canonical capacitor arrangement.
Informações de conformidade
RoHS compliant and lead-free per UTC product page (JLCPCB listing confirms 'LEAD FREE'). AEC-Q100 not qualified - for automotive use choose a Q-100 listed 7805 such as LM7805-Q1 from TI. REACH and conflict-mineral statements not found in verified web data.
