STMicroelectronics L7805ABP

Overview

L7805ABP from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 5 V ±2 % output with up to 1.5 A continuous current, thermal overload and short-circuit protection, and operation across –40 °C to +125 °C junction temperature. It serves as a local on-card power supply in industrial control modules, automotive body electronics, and embedded microcontroller power rails where stable 5 V bias is required.

For engineers reviewing the L7805ABP datasheet, L7805ABP pinout, L7805ABP application, or L7805ABP equivalent, key selection considerations include its guaranteed extended-temperature performance, 2 V dropout at 1 A, 68 dB supply voltage rejection at 120 Hz, 10 µV/√Hz output noise, and compatibility with standard TO-220FP mounting and heat sinking.

Technical Context

The L7805ABP implements a monolithic series-pass transistor architecture with internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry-enabling robust operation without external protection components. Its feedback loop maintains regulation under line variations from 7.5 V to 25 V input and load steps from 5 mA to 1.5 A.

Designed for fixed-output use, it requires only two external capacitors (0.33 µF input, 0.1 µF output) for stability per ST's test circuits. The device does not require a minimum load for regulation beyond 5 mA, and its output voltage drift is specified at –1.1 mV/°C over temperature.

Key Specifications

Pinout & Package

Supplied in TO-220FP package (3-lead, full-pack plastic, isolated tab), featuring vertical mounting capability and improved thermal resistance vs. standard TO-220 (R_thJC = 5 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output linear regulator applications.

Compared with LM7805CDT/NOPB, the L7805ABP delivers tighter regulation, wider temperature support, and lower noise-justifying its use in industrial and automotive contexts. Against MC7805BDTRKG, it offers superior PSRR and lower output noise while maintaining identical thermal and tolerance specs, making it preferable for mixed-signal applications.

Availability

L7805ABP is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, embedded microcontroller boards, and medical sensor interfaces requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for L7805ABP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensing solutions for industrial, automotive, and consumer markets.

The L78 series belongs to ST's legacy positive voltage regulator IC product line, engineered for rugged, low-cost, drop-in replacement of older 78xx regulators-with emphasis on extended temperature operation, integrated protection, and compatibility with legacy PCB footprints.

FAQ

What is the minimum input voltage required for stable 5 V output at 1.5 A?

The L7805ABP requires a minimum input voltage of 7.0 V under full-load conditions due to its 2.0 V dropout specification at 1 A (derated to ~2.1 V at 1.5 A). For reliable operation across temperature and line variation, ST recommends VI ≥ 7.5 V. Input below this risks dropout and output collapse, especially at high junction temperatures.

Can L7805ABP be used without a heatsink?

Yes, for loads ≤500 mA at ambient temperatures ≤40 °C and still-air conditions, the TO-220FP package's R_thJA of 60 °C/W allows operation within safe junction limits without a heatsink. At 1.5 A or elevated ambient, a heatsink reducing R_thJA to ≤25 °C/W is required to keep T_J ≤125 °C-verified using P_D = (V_IN – 5 V) × I_OUT and thermal calculations.

Does L7805ABP require an input bypass capacitor?

Yes-ST specifies a minimum 0.33 µF ceramic capacitor placed within 1 cm of the input pin to prevent oscillation and suppress high-frequency noise from upstream converters or long traces. Omitting it risks instability, especially with high-impedance sources or >10 cm input wiring. Tantalum or aluminum electrolytic caps alone are insufficient due to ESL limitations.

How does the L7805ABP behave during short-circuit events?

Under sustained short-circuit, the L7805ABP limits output current to ~0.2 A (steady-state) while monitoring die temperature. If junction temperature exceeds ~165 °C, thermal shutdown activates, disabling the pass element until cooldown. Upon recovery, it auto-restarts-no latch or manual reset required. Peak fault current reaches 2.2 A briefly before foldback engages.