STMicroelectronics L7809ABV

Overview

L7809ABV from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed 9 V output with ±2 % tolerance, 1.5 A maximum output current, thermal overload and short-circuit protection, and operation across –40 °C to +125 °C junction temperature-used for local regulation in industrial power supplies and embedded control modules.

For engineers reviewing the L7809ABV datasheet, L7809ABV pinout, L7809ABV application, or L7809ABV equivalent, key selection criteria include dropout voltage (2 V at 1 A), load regulation (≤100 mV over 5 mA–1.5 A), supply voltage rejection (61 dB at 120 Hz), output noise (10 µV/√Hz), and thermal resistance (5 °C/W junction-to-case in TO-220FP).

Technical Context

This monolithic IC integrates internal current limiting, safe operating area (SOA) protection, and thermal shutdown circuitry-enabling robust operation without external protection components. Its architecture relies on a PNP pass transistor with feedback-controlled reference and error amplifier, optimized for stability with minimal external capacitance (0.33 µF input, 0.1 µF output).

Designed for fixed-output use, it supports adjustable configurations via external resistive dividers but requires minimum 5 mA load current for regulation. Input voltage range is 11.5 V to 26 V for reliable 9 V output under full load and extended temperature conditions.

Key Specifications

Pinout & Package

Supplied in TO-220FP package-a full-molded, isolated-tab variant of TO-220 with improved thermal performance (R_thJC = 5 °C/W) and creepage clearance for safety-critical applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7809CD2TR and MC7809BD2TG, the L7809ABV offers superior voltage accuracy and guaranteed industrial temperature operation in TO-220FP-making it optimal for applications where regulation stability and thermal resilience outweigh package-size constraints.

Availability

L7809ABV is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control modules, medical diagnostic instrumentation, and point-of-sale terminal designs requiring stable component supply and long-term manufacturability.

Supply support for L7809ABV 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 silicon solutions for automotive, industrial, and consumer markets.

The L78 series targets cost-effective, robust local regulation in space-constrained and thermally demanding applications-emphasizing protection integration, wide temperature operation, and compatibility with standard linear regulator footprints.

FAQ

What is the minimum input voltage required for stable 9 V output at 1.5 A?

The L7809ABV requires a minimum input voltage of 11.5 V to maintain regulation at full 1.5 A load and 25 °C junction temperature. At higher temperatures or with poor heatsinking, input must exceed 11.5 V by margin to accommodate increased dropout and thermal derating-typically ≥13 V recommended for robust operation.

Can L7809ABV be used without an input bypass capacitor?

No-STMicroelectronics specifies a minimum 0.33 µF ceramic capacitor between IN and GND, placed as close as possible to the device. Omitting it risks oscillation, poor transient response, and potential instability due to parasitic inductance in PCB traces, especially under fast load steps or high-frequency noise.

How does thermal resistance differ between TO-220FP and standard TO-220 packages?

TO-220FP has R_thJC = 5 °C/W versus 5 °C/W for standard TO-220-but its molded isolation eliminates need for insulating washers, improving thermal transfer to heatsinks. R_thJA is 60 °C/W (TO-220FP) vs. 50 °C/W (TO-220), meaning TO-220FP requires slightly larger heatsink area for same power dissipation in still air.

Is L7809ABV compatible with lead-free reflow soldering processes?

Yes-L7809ABV in TO-220FP package is qualified for standard lead-free reflow per JEDEC J-STD-020, with peak temperature up to 260 °C for 30 seconds. The device's plastic body and internal wire bonds are rated for Pb-free assembly; no special prebake or moisture sensitivity level (MSL) handling is required.