STMicroelectronics L7815ABD2T

Overview

L7815ABD2T 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 protection, short-circuit protection, and ±2 % output voltage tolerance over –40 °C to +125 °C operating junction temperature. It serves as a local on-card power supply in industrial control modules requiring stable mid-rail biasing for op-amps and microcontroller peripherals.

For engineers reviewing the L7815ABD2T datasheet, L7815ABD2T pinout, L7815ABD2T application, or L7815ABD2T equivalent, key selection criteria include dropout voltage (2 V at 1 A), load regulation (≤30 mV from 5 mA to 1.5 A), supply voltage rejection (58 dB at 120 Hz), and TO-220FP package thermal resistance (R_thJC = 5 °C/W).

Technical Context

This device implements a monolithic series-pass regulator architecture with internal current limiting, safe-area protection, and thermal shutdown-enabling robust operation without external protection circuitry. Its fixed-output design eliminates feedback network complexity while maintaining tight DC accuracy across line, load, and temperature variations.

It operates with a minimum input-to-output differential of 2 V and requires only two external capacitors (0.33 µF input, 0.1 µF output) for stability. The TO-220FP package provides insulated mounting and enhanced thermal performance versus standard TO-220, supporting >1 A delivery with adequate heatsinking.

Key Specifications

Pinout & Package

The L7815ABD2T is housed in a TO-220FP package-a full-packaged, electrically insulated variant of TO-220 with vertical lead frame and metal tab for heatsinking. The plastic insulation eliminates need for insulating washers when mounted to grounded heat sinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM7815CD2T, L7815ABD2T adds guaranteed operation down to –40 °C and lower thermal resistance in TO-220FP; versus MC7815BD2TG, it offers 3.6 mA lower quiescent current and tighter load regulation (30 mV vs 100 mV), improving accuracy in precision analog designs.

Availability

L7815ABD2T is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, test equipment power subsystems, and medical diagnostic signal chains requiring stable component supply with traceable sourcing and long-term lifecycle management.

Supply support for L7815ABD2T 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 silicon solutions for automotive, industrial, and power management applications.

The L78 series belongs to ST's legacy positive voltage regulator IC product line, engineered for robust local regulation in cost-sensitive, high-reliability embedded systems where simplicity, protection, and thermal resilience are prioritized over ultra-low dropout or switching efficiency.

FAQ

What is the minimum input voltage required for regulation with L7815ABD2T?

The minimum input voltage is 17 V DC, calculated as the sum of the nominal output (15 V) and the maximum dropout voltage (2 V at 1 A and 25 °C). At higher loads or elevated temperatures, dropout may increase slightly; design margin should include worst-case thermal conditions and input ripple.

Can L7815ABD2T be used without a heatsink?

Yes, for low-power applications (<300 mA) at ambient temperatures ≤40 °C, the TO-220FP package can operate without an external heatsink. However, at 1 A continuous load, junction temperature rise exceeds safe limits without heatsinking-R_thJA = 60 °C/W implies ~60 °C rise above ambient, requiring thermal management per application conditions.

Does L7815ABD2T require input and output capacitors?

Yes: a minimum 0.33 µF ceramic capacitor must be placed within 1 cm of the IN pin, and a minimum 0.1 µF ceramic capacitor must be placed within 1 cm of the OUT pin. These stabilize internal feedback and suppress high-frequency oscillation; omitting them risks instability or output ripple amplification.

How does the thermal shutdown behave during overload conditions?

When junction temperature exceeds ~165 °C, the device disables the pass transistor and halts output current. Once the die cools by ~10–15 °C, regulation automatically resumes-no manual reset or power cycle is needed. This hiccup-mode behavior protects against sustained shorts while allowing recovery after transient faults.