LM7805L-TA3-T - 5V 1A Fixed Positive LDO Regulator | UTC TO-220
Артикул: LM7805L-TA3-T ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 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 Обзор
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.
Аналоги без доработки для LM7805L-TA3-T — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Варианты в этой серии
Модели той же серии, совместимые без доработки с LM7805L-TA3-T (тот же форм-фактор и посадочное место) — отличается по Package, Maximum Output Current, Mounting Type, Dropout Voltage, Input Voltage Range.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
LM7805CT/NOPB
✅ Прямая замена✓ В наличии
$0.74 / шт.
Открыть даташит →L7805CV
✅ Прямая замена✓ В наличии
$0.1464 / шт.
Открыть даташит →MC7805CTG
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
LM7805CT/NOPB
✅ Прямая замена✓ В наличии
$0.74 / шт.
Открыть даташит →TS7805CZ
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
LM7805L-TA3-T Максимальные параметры и электрические характеристики
| Regulator Type | Standard Linear (LDO family) |
| Output Polarity | Positive |
| Output Voltage Type | Fixed |
| Выходное напряжение | 5 V (nominal) |
| Output Voltage Tolerance | ±4% (4.75 V to 5.25 V) |
| Максимальный выходной ток | 1 A |
| Диапазон входного напряжения | Up to 35 V |
| Напряжение падения | 2 V (typical at 1 A) |
| Ток покоя | 8 mA (typical) |
| PSRR (Ripple Rejection) | 80 dB at 120 Hz |
| Output Noise Voltage | 40 uV (typical) |
| Рабочая температура перехода | -20 C to +125 C |
| Protection Features | Over Current Protection, Over Temperature Protection |
| Корпус | TO-220 (3-pin, through-hole) |
| Тип монтажа | Through-Hole |
| Lead-Free / RoHS | Lead Free, ROHS compliant |
Конфигурация выводов LM7805L-TA3-T
| Контакт 1 | IN — Unregulated input voltage (up to 35 V) |
| Контакт 2 | GND — Common ground (also bonded to the metal tab on TA3) |
| Контакт 3 | OUT — Regulated 5 V output (up to 1 A) |
Типичное применение
LM7805L-TA3-T подходит для 6 применениеs: 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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для LM7805L-TA3-T — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | 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 |
Ключевые отличия
- Lowest unit cost in the 7805 family (против LM7805CT/NOPB)
- Wider output tolerance for non-precision loads (против L7805CV)
- GND-bonded tab simplifies heatsink mounting (против MC7805CTG)
Заметки по проектированию
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.
Информация о соответствии
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.
