This document describes the features and characteristics of the KA78XX/KA78XXA series of three-terminal positive regulators produced by Fairchild Semiconductor Corporation. These regulators have an output current of up to 1A, multiple selectable output voltages, thermal overload protection, short circuit protection, etc. They employ internal current limiting, thermal shutdown, and safe operating area protection, making them virtually indestructible. With adequate heat sinking, they can deliver over 1A of output current. Although primarily designed as fixed voltage regulators, they can be used with external components to obtain adjustable voltages and currents.
The KA78XX/KA78XXA series are 3‑terminal positive voltage regulators offered in TO‑220 and D‑PAK packages. They provide fixed output voltages ranging from 5 V to 24 V and include internal current limiting, thermal shutdown, and safe‑operating‑area protection.
The document lists absolute maximum ratings, detailed electrical characteristics for each voltage version, ordering information, and legal disclaimer. It is intended for designers who need precise specifications for circuit integration.
| Output Current | up to 1 A |
|---|---|
| Output Voltages | 5 V, 6 V, 8 V, 9 V, 10 V, 12 V, 15 V, 18 V, 24 V |
| Thermal Overload Protection | Yes |
| Short Circuit Protection | Yes |
| Package Types | TO‑220, D‑PAK |
The dropout voltage is about 2 V when the regulator supplies 1 A.
They are offered in TO‑220 and D‑PAK surface‑mount packages.