STMicroelectronics L149V

Overview

L149V from STMicroelectronics is a linear power booster IC in Pentawatt® package, functioning as a quasi-complementary Darlington output stage with integrated biasing and inhibit control. It delivers 4 A peak output current, 10,000 typical current gain, ±20 V supply operation, thermal/short-circuit protection, and 30 V/µs slew rate-designed for op-amp current boosting in high-fidelity audio amplifiers.

For engineers reviewing the L149V datasheet, L149V pinout, L149V application, or L149V equivalent, key selection criteria include SOA compliance, input inhibit logic thresholds (±0.3 V ON / ±1.8 V OFF), saturation voltage ≤3.5 V at 3 A, quiescent current of 30 mA, and thermal resistance of 3 °C/W junction-to-case.

Technical Context

The L149V operates as a unity-gain current amplifier in closed-loop configurations, where an external op-amp sets precision voltage while the L149V handles high-current delivery. Its quasi-complementary Darlington topology enables high h_FE (6000–10,000) and low V_CE(sat) (3.5 V @ 3 A), maintaining stability within Safe Operating Area under dynamic load conditions.

Internal current limiting and thermal shutdown activate before damage occurs; the inhibit function (pins 1–3) disables output via TTL/CMOS-compatible voltage thresholds. Supply rejection remains >60 dB up to 100 kHz, supporting clean signal amplification in noise-sensitive analog systems.

Key Specifications

Pinout & Package

Packaged in Pentawatt® V (vertical mount, 5-pin single-in-line), with leads spaced 2.54 mm, body height ~10.4 mm, and resin isolation between pins for high-voltage isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear power booster applications.

Compared with TCA0372 and LM12CL, the L149V uniquely balances integrated protection, 4 A capability, and simple op-amp interfacing in a single Pentawatt® package-ideal for cost- and reliability-sensitive mid-power linear amplification.

Availability

L149V is available at Aetrix Electronics and suitable for professional audio amplifiers, industrial servo drivers, programmable test equipment power stages, and high-current linear regulator designs requiring stable component supply and long-term BOM continuity.

Supply support for L149V 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, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The L149V belongs to ST's legacy linear power IC product line, engineered specifically for high-fidelity analog signal amplification and robust current boosting in demanding linear applications.

FAQ

Is the L149V still in active production?

No-the L149V is marked "Obsolete Product(s)" in its official STMicroelectronics datasheet (July 2003). However, Aetrix Electronics maintains legacy inventory with full traceability and offers extended lifecycle support including obsolescence forecasting and cross-reference guidance for drop-in or redesign alternatives.

Can the L149V be used in single-supply configurations?

Yes, but only with external level-shifting circuitry. The L149V is inherently dual-supply (±V_S), and its input common-mode range and output swing are centered around ground. Single-supply use requires biasing the input and load reference to mid-rail and verifying SOA limits under asymmetric voltage stress.

What heatsink is recommended for continuous 3 A operation?

With R_th(j-c) = 3 °C/W and P_tot = 25 W at T_case = 75 °C, a heatsink with R_th(c-s) ≤ 1.5 °C/W is required for ambient ≤50 °C. STMicroelectronics Application Note AN111 recommends finned aluminum extrusions (e.g., Aavid 5120BG) mounted with thermal grease and mechanical clamping.

Does the inhibit function affect quiescent current?

Yes-inhibited state reduces I_Q from 30 mA to <1 mA by disabling bias current to both Darlington pairs. This is confirmed in the Electrical Characteristics table under "I_Q" test condition "Inhibit = ON", and enables low-power standby modes in battery-backed or energy-conscious systems.