Diodes Incorporated ZTX792A

Overview

ZTX792A from Zetex Semiconductors (now Diodes Incorporated) is a PNP silicon planar medium-power high-gain bipolar junction transistor designed for switching and linear amplification in low-voltage, moderate-current applications. It features V_CEO = −70 V, h_FE = 800 at I_C = −10 mA, V_CE(sat) = −0.45 V at I_C = −500 mA/I_B = −5 mA, and f_T = 100 MHz - enabling use in flash gun converters and motor drivers where low saturation loss and robust gain are critical.

For engineers reviewing the ZTX792A datasheet, ZTX792A pinout, ZTX792A application, or ZTX792A equivalent, key selection criteria include its TO-92-compatible E-Line package, PNP polarity with −2 A continuous collector current rating, −1.5 W practical PCB-mounted power dissipation, and verified performance across −55°C to +200°C junction temperature range.

Technical Context

The ZTX792A operates as a medium-power PNP BJT optimized for high-current switching with minimal voltage drop: it delivers V_CE(sat) ≤ −0.5 V at I_C = −2 A/I_B = −200 mA and maintains h_FE ≥ 200 up to I_C = −1 A under V_CE = −2 V bias. Its f_T = 100 MHz supports fast switching in pulse-driven circuits like camera flash inverters.

Thermal design is enabled by R_th(j–amb) = 175 °C/W (free air) and 116 °C/W (1-inch² PCB copper), with safe operating area validated for single-pulse conditions up to 2 A/−70 V. The device meets absolute maximum ratings including V_CBO = −75 V, V_EBO = −5 V, and T_j = +200°C.

Key Specifications

Pinout & Package

Package: TO-92-compatible E-Line (3-lead, plastic, through-hole); lead configuration confirmed as Emitter–Base–Collector (E-B-C) from pin 1 to pin 3 per Zetex documentation and Diodes Incorporated ZTX792A datasheet Figure 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD2955 and BC807-40, the ZTX792A uniquely balances TO-92 mountability, 2 A capability, and high h_FE, making it optimal for space-limited, gain-sensitive medium-power switching where thermal mass is constrained and no heatsink can be added.

Availability

ZTX792A is available at Aetrix Electronics and suitable for flash gun converters, battery-powered motor drivers, Darlington pair drivers, and industrial battery management systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZTX792A 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

Zetex Semiconductors was a UK-based analog and discrete semiconductor specialist acquired by Diodes Incorporated in 2008; known for high-performance BJTs, MOSFETs, and interface ICs targeting precision and ruggedness.

The ZTX series was developed specifically for medium-power linear and switching applications demanding high gain, low saturation, and wide temperature resilience - especially in portable, automotive, and industrial power stages.

FAQ

What is the maximum continuous collector current for ZTX792A?

The ZTX792A is rated for −2 A continuous collector current (I_C) at T_amb = 25°C with adequate PCB copper area. Derating applies above 25°C: 5.7 mW/°C reduction in P_tot ensures safe operation up to +125°C ambient when mounted on ≥1 inch² copper.

Can ZTX792A replace a BC557 in a linear amplifier circuit?

No - while both are PNP BJTs, the ZTX792A has significantly higher current capability (−2 A vs. −100 mA), larger package (TO-92 E-Line vs. standard TO-92), and different h_FE profile (300–800 vs. 125–800). Substitution requires verifying bias network compatibility and thermal layout changes.

Is ZTX792A RoHS compliant and halogen-free?

Yes - as a Diodes Incorporated product, ZTX792A conforms to RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. Full compliance documentation is available under Diodes' part number ZTX792ASTZ with date code tracking.

What is the recommended PCB layout for optimal thermal performance?

Mount ZTX792A using minimum 1-inch² copper pour connected directly to the emitter pad (Pin 1) via multiple thermal vias. Avoid narrow traces on collector/base lines; keep base resistor close to Pin 2. Thermal resistance drops from 175 to 116 °C/W when using this layout, enabling full 1.5 W dissipation at +70°C ambient.