STMicroelectronics L296HT

Overview

L296HT from STMicroelectronics is a high-current stepdown switching regulator delivering 4 A output current with adjustable output voltage from 5.1 V to 40 V, ±2 % on-chip reference accuracy, 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 L296HT datasheet, L296HT pinout, L296HT application, or L296HT equivalent, key selection concerns include output current capability, external current limit programming (L296P variant), crowbar overvoltage protection interface, remote inhibit control, and Multiwatt-15 horizontal package thermal performance.

Technical Context

The L296HT implements a fixed-frequency PWM regulation loop using an internal 5.1 V zener-zap-trimmed reference, sawtooth oscillator, error amplifier, and comparator driving a high-current output stage. Regulation stability is set via external RC network on pin 9 (frequency compensation).

It supports synchronization across multiple units via pin 7 (SYNC INPUT), provides open-collector reset output (pin 14) with programmable delay (pin 13), and integrates crowbar circuitry with voltage sense input (pin 1) and SCR gate drive output (pin 15) for overvoltage protection at ±20 % threshold deviation.

Key Specifications

Pinout & Package

Package: Multiwatt-15 horizontal (HT suffix), thermally enhanced plastic power package with exposed metal tab (R_{th j-case} = 3 °C/W), designed for heatsink mounting and high-power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with L296PHT, L296HT lacks external current limit adjustment but shares identical pinout, thermal performance, and crowbar/reset functionality; versus LM2678-ADJ, it provides integrated protection and sequencing features at the cost of higher component count and larger package.

Availability

L296HT is available at Aetrix Electronics and suitable for industrial power supplies, automated test equipment, motor drive pre-regulators, and telecom distributed power systems requiring stable component supply and long-term obsolescence management.

Supply support for L296HT 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, specializing in power management, automotive ICs, and industrial control solutions.

The L296 series belongs to ST's high-current monolithic switching regulator product line, designed specifically for rugged industrial and programmable power applications demanding reliability, integrated protection, and minimal external components.

FAQ

What is the difference between L296HT and L296PHT?

L296HT is the horizontal-mount version of the standard L296 regulator with fixed internal current limiting. L296PHT is the horizontal-mount variant of the L296P, which adds external programmability of the current limit threshold via a resistor on pin 4. Both share identical pinout, thermal characteristics, crowbar, reset, and sync functionality - the sole functional distinction is current limit adjustability.

Can L296HT be used for 5.1 V fixed-output applications without external feedback components?

Yes - connecting pin 10 (feedback input) directly to pin 2 (output) configures L296HT for fixed 5.1 V output, leveraging its internal ±2 % trimmed reference. No external resistors or dividers are required. The minimal application circuit (Figure 36 in datasheet) confirms this configuration uses only input/output capacitors, inductor, and recirculation diode.

Does L296HT support synchronization with other switching regulators?

Yes - pin 7 (SYNC INPUT) allows multiple L296HT units to operate in phase-aligned mode. One device uses its internal oscillator (pins 11 and 7 tied), while others connect pin 7 to that master's pin 7 and omit their own oscillator RC network. This reduces beat frequencies and EMI in multi-rail systems, as confirmed in Figure 40 of the datasheet.

What thermal derating applies to L296HT at elevated ambient temperatures?

L296HT has R_{th j-amb} = 35 °C/W maximum. At T_amb = 70 °C, maximum allowable power dissipation drops to ~5.7 W (from 20 W at T_case ≤ 90 °C), implying ~1.5 A output at 12 V (assuming 2 V dropout and 85 % efficiency). Derating curves in Figure 22 confirm linear reduction above 25 °C ambient, requiring heatsink design per actual layout and airflow.