STMicroelectronics L7815ABD2T-TR

Overview

L7815ABD2T-TR from STMicroelectronics is a three-terminal positive linear voltage regulator delivering a fixed +15 V output with up to 1.5 A continuous current, thermal overload and short-circuit protection, and ±2 % output voltage tolerance over −40 °C to +125 °C operating junction temperature. It uses a TO-220FP package and serves as a local on-card power supply in industrial control modules requiring stable, low-noise 15 V bias for op-amps, microcontrollers, and analog sensors.

For engineers reviewing the L7815ABD2T-TR datasheet, L7815ABD2T-TR pinout, L7815ABD2T-TR application, or L7815ABD2T-TR equivalent, key selection criteria include guaranteed operation across extended temperature, dropout voltage of 2 V at 1 A, load regulation ≤100 mV (5 mA–1.5 A), supply voltage rejection of 58 dB at 120 Hz, and thermal resistance junction-to-case of 5 °C/W in TO-220FP.

Technical Context

This device implements a monolithic series-pass linear regulator architecture with internal current limiting, safe-area protection, and thermal shutdown circuitry. Its feedback loop maintains regulated output under varying line (VI = 17.5–30 V) and load (IO = 5 mA–1.5 A) conditions while sustaining 15 V ±2 % accuracy at TJ = −40 to +125 °C.

The L7815ABD2T-TR requires only two external capacitors (CI ≥ 0.33 µF, CO ≥ 0.1 µF) for stability and ripple suppression. Its 2 V dropout enables use with 17.5 V minimum input in 15 V systems, and its 10 µV/√Hz output noise supports precision analog signal chains without additional filtering.

Key Specifications

Pinout & Package

Package: TO-220FP (3-lead, vertical mounting, isolated tab, 5 °C/W R_thJC).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7815CD2T, the L7815ABD2T-TR adds guaranteed −40 °C startup and tighter thermal derating control; versus MC7815BD2TG, it offers superior thermal resistance (5 vs. 8 °C/W) and lower quiescent current (4.4–6 vs. 8 mA), making it preferred for high-reliability through-hole designs with moderate power dissipation.

Availability

L7815ABD2T-TR is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, programmable logic controller I/O cards, and test equipment requiring stable component supply with long-term lifecycle assurance.

Supply support for L7815ABD2T-TR 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The L78 series is ST's flagship family of three-terminal positive linear regulators, engineered for robustness and ease-of-use in local on-card regulation across harsh environments - emphasizing thermal resilience, intrinsic protection, and wide-input-range compatibility.

FAQ

What is the minimum input voltage required for stable 15 V output?

The L7815ABD2T-TR requires a minimum input voltage of 17.5 V to maintain regulation at full 1.5 A load and maximum junction temperature, based on its 2 V dropout specification. At lighter loads or lower temperatures, operation down to 17 V is feasible, but design margin should retain ≥17.5 V under worst-case conditions including line drop and ripple.

Can this regulator be used without a heatsink?

Yes, for loads ≤300 mA at 25 °C ambient with adequate PCB copper area (≥4 cm² 2 oz copper pour under tab), the TO-220FP package can dissipate heat without an external heatsink. Above that, thermal calculations using R_thJA = 60 °C/W show junction temperature exceeding 125 °C; a heatsink or forced airflow is required for sustained >0.5 A operation.

Does it require input and output capacitors, and what values are recommended?

Yes: a minimum 0.33 µF ceramic capacitor on the input (close to Pin 1) and 0.1 µF ceramic on the output (close to Pin 3) are mandatory for stability per the datasheet. For improved transient response and ripple rejection, 10 µF–100 µF low-ESR electrolytic or tantalum capacitors may be added in parallel, but the ceramics must remain in place.

How does its short-circuit protection behave during sustained fault conditions?

Under sustained short-circuit, the L7815ABD2T-TR limits output current to ~220 mA (I_sc) and activates thermal shutdown when junction temperature reaches ~165 °C. It cycles on/off autonomously until the fault is removed, preventing damage. Peak short-circuit current reaches 2.2 A briefly (<100 ms), sufficient to blow a properly rated fuse upstream if needed.