Diodes Incorporated ZTX690BSTZ

Overview

ZTX690BSTZ from Diodes Incorporated is an NPN silicon planar medium-power high-gain transistor with V_CEO = 45 V, h_FE = 400 at I_C = 1 A, and V_CE(sat) = 0.5 V (I_C = 1 A, I_B = 5 mA), designed for Darlington pair replacement and motor driver stages in battery-powered industrial control modules.

For engineers reviewing the ZTX690BSTZ datasheet, ZTX690BSTZ pinout, ZTX690BSTZ application, or ZTX690BSTZ equivalent, key selection criteria include saturation voltage under 1 A load, thermal resistance of 70 °C/W (junction-to-case), gain stability across −55°C to +175°C, and TO-92 package compatibility with legacy E-Line footprints.

Technical Context

This transistor operates as a medium-power switching and linear amplification device with a transition frequency of 150 MHz at I_C = 50 mA and V_CE = 5 V, supporting fast-switching siren and pulse-width modulated motor drive waveforms. Its low V_CE(sat) and high h_FE enable efficient current amplification without external base drive boosting.

The device features a maximum continuous collector current of 2 A and practical PCB-mounted power dissipation of 1.5 W, with thermal derating starting at 5.7 mW/°C above 25°C ambient. Junction temperature range spans −55°C to +200°C, validated for use in automotive under-hood and industrial motor-control environments.

Key Specifications

Pinout & Package

Package: TO-92 (E-Line compatible, 3-238 outline), molded plastic with axial leads; standard lead form per JEDEC TO-92 variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX653BSTZ and MJD112G, the ZTX690BSTZ uniquely balances high gain, low saturation voltage, and TO-92 compatibility-making it optimal for compact, battery-efficient switching where 45 V rating suffices and thermal management relies on PCB copper rather than external heatsinks.

Availability

ZTX690BSTZ is available at Aetrix Electronics and suitable for DC motor control, siren drivers, Darlington pre-drivers, and battery-powered load switching requiring stable component supply and long-term industrial availability.

Supply support for ZTX690BSTZ 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 components for industrial, automotive, and computing markets.

The ZTX690BSTZ belongs to Diodes' ZTX series of medium-power bipolar transistors, engineered for robust switching and amplification in cost-sensitive, thermally constrained applications where TO-92 packaging and predictable gain are critical.

FAQ

What is the maximum safe continuous collector current for ZTX690BSTZ?

The ZTX690BSTZ is rated for 2 A continuous collector current at T_amb = 25°C with adequate PCB copper (≥1 in²). Derating begins at 5.7 mW/°C above 25°C, limiting usable current to ~1.2 A at 70°C ambient unless additional heatsinking is applied to the case or PCB.

Does ZTX690BSTZ support switching at 20 kHz PWM frequencies?

Yes - with f_T = 150 MHz and measured switching times of t_on = 33 ns and t_off = 1300 ns, the ZTX690BSTZ fully supports 20 kHz PWM operation. At I_C = 1 A, total switching energy loss remains below 10 µJ per cycle, ensuring minimal heating in motor or lighting control applications.

Is ZTX690BSTZ pin-compatible with older ZTX690B variants?

Yes - ZTX690BSTZ uses the same TO-92 package (E-Line 3-238 outline) and identical C-B-E pinout as legacy ZTX690B. No PCB layout changes are needed; it is a direct replacement with improved gain consistency and tighter V_CE(sat) specifications.

Can ZTX690BSTZ be used in linear amplifier configurations?

Yes - its h_FE linearity across I_C = 100 mA to 2 A and V_CE = 2 V bias point supports Class-A and Class-AB small-signal amplification. However, thermal limitations restrict sustained linear operation to ≤500 mW output power without forced cooling due to R_th(j-amb) = 175 °C/W on standard PCBs.