Features

NPN bipolar transistor
High current capability for its package class
High DC current gain (hFE)
Suitable for switching applications
Suitable for audio and general-purpose amplification
Fast switching characteristics
Compact through-hole package
Easy to integrate into conventional PCB designs
Useful for both new designs and replacement/repair work

Typical Applications

Electronic switching circuits
Audio amplifier stages
Power-control circuits
LED switching and driver circuits
Relay driver circuits
General-purpose transistor amplifiers
Signal-processing circuits
Electronic repair and replacement
Microcontroller-controlled switching

How It Works

The ZTX690B has three terminals:

Base (B) – controls the transistor
Collector (C) – carries the controlled current
Emitter (E) – provides the current return path

A small base current allows a larger collector-to-emitter current to flow. This makes the transistor useful for controlling loads that cannot be driven directly from a low-current control signal.

Important Specifications

Parameter	Description
Type	NPN BJT
Configuration	Single transistor
Terminals	Base, Collector, Emitter
Mounting	Through-hole
Main Functions	Switching & amplification
Applications	General-purpose, audio, driver circuits

ZTX690B NPN Transistor