Diodes Incorporated ZTX692B

Overview

ZTX692B from Diodes Incorporated is an NPN silicon planar medium-power high-gain transistor designed for switching and linear amplification in low-voltage, moderate-current circuits. It delivers V_CEO = 70 V, h_FE = 400 at I_C = 500 mA, and V_CE(sat) = 0.15 V (typ.) at I_C = 0.1 A / I_B = 0.5 mA - enabling efficient relay and motor drive stages in battery-powered industrial controls.

For engineers reviewing the ZTX692B datasheet, ZTX692B pinout, ZTX692B application, or ZTX692B equivalent, key selection criteria include its 70 V breakdown rating, 1 A continuous collector current capability, low saturation voltage under medium load, TO-92 package thermal performance, and verified gain stability across –55°C to +175°C junction temperature range.

Technical Context

The ZTX692B operates as a discrete NPN bipolar junction transistor with fixed-emitter configuration and base-controlled current amplification. Its design emphasizes high DC current gain (h_FE ≥ 400 at 500 mA) and low V_CE(sat) to minimize conduction loss in saturated-switching applications such as Darlington pair drivers and solenoid interfaces.

Thermal management is defined by R_th(j–amb) = 175 °C/W (free air) and 116 °C/W (1-in² PCB copper), supporting operation up to +200°C storage and +175°C junction temperature. Transition frequency f_T = 150 MHz confirms suitability for medium-speed switching (t_on/t_off = 46/1440 ns) but not RF amplification.

Key Specifications

Pinout & Package

Package: TO-92 (E-Line compatible, 3-lead plastic). Standard lead assignment: Emitter (pin 1), Base (pin 2), Collector (pin 3), viewed from flat side with leads down.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN medium-power switching applications.

Compared with ZTX653 and MJD2955, the ZTX692B uniquely balances 70 V rating, 400 h_FE, and TO-92 thermal efficiency - making it optimal for space-constrained, battery-aware, and 48 V industrial switching where gain stability and low V_CE(sat) are critical.

Availability

ZTX692B is available at Aetrix Electronics and suitable for relay drivers, battery-powered motor control, Darlington input stages, and industrial sensor interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZTX692B 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, application-optimized components for industrial, automotive, and computing markets.

The ZTX692B belongs to Diodes' ZTX series of high-gain, medium-power bipolar transistors engineered specifically for robust switching and amplification in harsh-environment control systems - emphasizing thermal resilience, gain consistency, and manufacturable TO-92 reliability.

FAQ

What is the maximum safe continuous collector current for ZTX692B at 70°C ambient?

At 70°C ambient temperature with 1-in² PCB copper, the ZTX692B's thermal resistance is 116 °C/W. With T_j(max) = +175°C, allowable ΔT = 105°C, permitting P_tot = 0.91 W. Using V_CE(sat) ≈ 0.3 V at 1 A, max continuous I_C is ~1.0 A - matching its rated 1 A specification under those conditions.

Can ZTX692B be used in linear amplification mode with stable gain?

Yes - h_FE is specified from 100 mA to 1 A (min 150, typ 400) at V_CE = 2 V, and gain variation is < ±15% across that range. Its f_T = 150 MHz and low C_obo = 12 pF support stable mid-band amplification up to ~10 MHz with proper emitter degeneration and thermal stabilization.

Is ZTX692B pin-compatible with legacy TO-92 NPN transistors like BC548?

No - while both use TO-92 packages, ZTX692B has E-B-C pinout (flat side view, leads down), whereas BC548 uses E-C-B. Swapping them without board revision causes immediate reverse-bias failure. Always verify pin assignment using the "3-241" marking diagram in the official datasheet.

Does ZTX692B require a base resistor in switching applications?

Yes - base current must be limited to prevent damage and ensure saturation. For I_C = 500 mA and h_FE = 400, minimum I_B = 1.25 mA. With V_BE(sat) ≈ 0.9 V and 3.3 V GPIO drive, a 2.2 kΩ series resistor delivers ~1.1 mA - sufficient for reliable saturation while avoiding excessive base dissipation.