STMicroelectronics L7806CT

Overview

L7806CT from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 6 V ±2% output at up to 1.5 A, featuring thermal overload protection, short-circuit protection, and safe operating area (SOA) protection. It operates with input voltages up to 35 V (for 6 V output), maintains regulation down to 5 mA load, and is commonly used in industrial power supplies, embedded control boards, and local point-of-load regulation where stable low-noise DC voltage is required.

For engineers reviewing the L7806CT datasheet, L7806CT pinout, L7806CT application, or L7806CT equivalent, key selection considerations include dropout voltage (2 V @ 1 A), load regulation (≤120 mV over 5 mA–1.5 A), supply voltage rejection (59 dB @ 120 Hz), junction temperature range (0 to 125 °C), and TO-220 package thermal resistance (R_thJA = 50 °C/W).

Technical Context

The L7806CT implements a monolithic series-pass linear regulation architecture with internal current limiting, thermal shutdown, and SOA protection-enabling robust operation without external protection circuitry. Its feedback loop stabilizes output voltage against line and load variations while maintaining low output noise (45 µV/√Hz, 10 Hz–100 kHz).

Designed for fixed-output use, it requires only two external capacitors (0.33 µF input, 0.1 µF output) for stability per standard application circuits. The device's 2 V dropout voltage and 17–19 mΩ output resistance define its dynamic response and load transient behavior under varying conditions.

Key Specifications

Pinout & Package

Package: TO-220 (3-pin, vertical mounting, metal tab connected to GND). Standard through-hole package with integrated heat transfer via tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7806CDT, L7806CT offers superior ripple rejection and lower output noise-critical for analog signal chains-while MC7806CT adds extended temperature qualification at identical performance, making it suitable for harsh-environment deployments where L7806CT's commercial-grade rating (0–125 °C) is insufficient.

Availability

L7806CT is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and point-of-sale terminal designs requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for L7806CT 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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The L78 series belongs to ST's legacy linear regulator product line, designed specifically for cost-effective, robust local DC-DC conversion in space-constrained and thermally demanding applications where switching noise must be avoided.

FAQ

What is the minimum load current required for regulation?

The L7806CT requires a minimum load current of 5 mA to maintain regulation. Below this threshold, output voltage may rise above nominal due to internal biasing limitations. Applications with intermittent or ultra-low-power sleep modes should include a bleeder resistor (e.g., 1.2 kΩ) to ensure compliance.

Can L7806CT be used with an input voltage below 8 V?

No-operation below 8 V violates the recommended input range and risks dropout. At 1 A load, the 2 V dropout requires ≥8 V input; at lighter loads, regulation degrades below ~7.5 V. Sustained use below specification risks output instability and increased thermal stress.

Is a heat sink mandatory for 1.5 A operation?

Yes-without a heat sink, the TO-220 package's R_thJA = 50 °C/W causes junction temperature to exceed 125 °C at 1.5 A with >10 °C/W ambient rise. A 10 °C/W heatsink (e.g., Aavid 5780) is recommended to sustain full-rated current at 50 °C ambient.

How does the L7806CT behave during short-circuit events?

Under short-circuit, the L7806CT limits output current to ~0.55 A (sustained) and activates thermal shutdown if junction temperature exceeds ~165 °C. It recovers automatically once cooled, with no latch-up or damage-enabling "fire-and-forget" protection in field-deployed equipment.