STMicroelectronics L296

Overview

L296 from STMicroelectronics is a monolithic stepdown switching regulator delivering 4 A output current with adjustable output voltage from 5.1 V to 40 V, ±2 % on-chip reference, up to 200 kHz switching frequency, and integrated soft start, reset output, thermal shutdown, and crowbar SCR drive - used in industrial power supplies and programmable DC sources.

For engineers reviewing the L296 datasheet, L296 pinout, L296 application, or L296 equivalent, this device supports remote inhibit, synchronous PWM operation, external current limiting (L296P variant), overvoltage crowbar protection, and high-efficiency (>90 %) regulation in multiwatt-15 package - critical for stable high-current DC-DC conversion where thermal robustness and system-level fault management are required.

Technical Context

The L296 implements a fixed-frequency PWM control architecture with an internal 5.1 V zener-zap-trimmed reference, sawtooth oscillator, error amplifier, and comparator driving an integrated power switch stage. Regulation loop stability is externally adjustable via RC network on pin 9.

It integrates multiple system-level functions: open-collector reset output (pin 14) with programmable delay (pin 13), TTL-compatible inhibit input (pin 6), synchronization input (pin 7), crowbar sense (pin 1) and gate drive (pin 15), and soft-start timing (pin 5) - enabling coordinated power sequencing and fault containment in multi-rail systems.

Key Specifications

Pinout & Package

The L296 is housed in a 15-lead Multiwatt^® plastic power package (vertical orientation), featuring integrated heat slug for direct PCB thermal coupling and rated for 20 W power dissipation at T_case ≤ 90 °C (R_{th j-case} = 3 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current stepdown regulator applications.

Compared with LM2678-ADJ and TPS54620, the L296 provides unique integration of crowbar protection, programmable reset with delay, and multi-device synchronization - making it irreplaceable in applications demanding fail-safe overvoltage response and deterministic power sequencing.

Availability

L296 is available at Aetrix Electronics and suitable for industrial programmable power supplies, distributed power systems, embedded system power sequencing, and remote load regulation requiring stable component supply and long-term lifecycle support.

Supply support for L296 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, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The L296 belongs to ST's legacy high-current switching regulator product line, engineered specifically for rugged industrial power conversion where integrated fault management, thermal resilience, and system-level coordination (sync, reset, inhibit) are mandatory.

FAQ

What is the difference between L296 and L296P?

The L296P adds external programmable current limiting via pin 4, allowing precise adjustment of overcurrent threshold using a resistor-to-ground. The standard L296 uses an internal fixed threshold (~4.5–7.5 A). Both share identical pinout, thermal shutdown, reset, sync, and crowbar functionality - the P variant targets applications needing tighter current tolerance or dynamic current scaling.

Can L296 operate with input voltage below 5.1 V?

No - the L296 requires minimum input voltage of 9 V per electrical characteristics (Vi ≥ 9 V for Vo = Vref to 36 V). Its internal regulator and switch driver cannot function reliably below this threshold. For sub-5.1 V outputs, a buck-boost or LDO solution is required; the L296 is strictly a stepdown regulator with Vin > Vout + dropout (≥2 V at 4 A).

How is crowbar protection implemented with L296?

Crowbar protection uses pin 1 (voltage sense) to monitor output or input voltage and pin 15 (SCR gate drive) to deliver up to 100 mA to trigger an external SCR. When sensed voltage exceeds nominal by ~20 %, the internal comparator activates pin 15, shorting the output through the SCR - acting independently of the regulation loop for sub-microsecond fault response.

Is thermal derating required for continuous 4 A operation?

Yes - at ambient temperatures above 55 °C or with insufficient heatsinking, power dissipation must be limited. With R_{th j-amb} = 35 °C/W, 4 A at 12 V output (Vin = 35 V) yields ~90 W input power and ~25 W device dissipation, requiring active cooling or derated output current. Derating curves in datasheet Figure 22 specify safe operating area based on case temperature.