Diodes Incorporated ZTX795ASTOB

Overview

ZTX795ASTOB from Diodes Incorporated is a PNP silicon planar medium-power high-gain bipolar junction transistor (BJT) designed for linear amplification and switching in industrial power control circuits. It delivers V_CEO = −140 V, h_FE = 250 at I_C = −0.2 A, and V_CE(sat) = −0.25 V at I_C = −500 mA / I_B = −50 mA - enabling robust operation in high-voltage DC-DC converters and relay drivers.

For engineers reviewing the ZTX795ASTOB datasheet, ZTX795ASTOB pinout, ZTX795ASTOB application, or ZTX795ASTOB equivalent, key selection criteria include verified PNP polarity, TO-92-compatible E-Line package thermal performance (R_th(j-amb) = 175 °C/W on 1-in² PCB copper), −140 V breakdown rating, low saturation voltage under high current, and gain stability across −55°C to +200°C junction temperature range.

Technical Context

This PNP BJT operates with emitter-grounded configuration in common-emitter amplifier and switch topologies. Its −140 V V_CEO and −140 V V_CBO support high-side switching in off-line power supplies, while f_T = 100 MHz enables stable gain up to audio and low-RF frequencies.

Thermal design relies on its dual thermal resistance ratings: R_th(j-amb) = 175 °C/W (free-air) and 116 °C/W (1-in² PCB copper), with R_th(j-case) = 70 °C/W confirming direct case-to-heatsink path viability. Saturation behavior is characterized at three drive levels (I_B/I_C = 10, 20, 40), supporting predictable turn-on timing in pulse-width modulated loads.

Key Specifications

Pinout & Package

Package: E-Line TO-92-compatible plastic package (3-lead, straight lead form), optimized for through-hole mounting on standard FR-4 PCBs with ≥1 in² copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-voltage switching applications.

Compared with ZTX753STOB and MJD2955T4G, ZTX795ASTOB uniquely balances −140 V breakdown, TO-92 mountability, and 250 h_FE, making it optimal for space-constrained, medium-current, high-voltage industrial controls where thermal derating and gain consistency are critical.

Availability

ZTX795ASTOB is available at Aetrix Electronics and suitable for industrial relay drivers, high-voltage linear regulators, DC-DC converter high-side switches, and overvoltage crowbar circuits requiring stable component supply across extended temperature and voltage ranges.

Supply support for ZTX795ASTOB 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 applications.

ZTX795ASTOB belongs to the ZTX series of high-voltage PNP transistors engineered for ruggedized power control in harsh-environment equipment such as factory automation systems and power infrastructure.

FAQ

What is the maximum safe continuous collector current for ZTX795ASTOB at 75°C ambient?

At T_amb = 75°C, derating from P_tot = 1.5 W at 25°C applies at 5.7 mW/°C. This yields 1.5 W − (50°C × 5.7 mW/°C) = 1.215 W max dissipation. Using V_CE(sat) ≈ −0.28 V at I_C = −400 mA, I_C(max) ≈ √(P_diss/R_CE(sat)) ≈ 420 mA - confirmed by datasheet's I_C = −0.5 A absolute max rating with appropriate thermal layout.

Can ZTX795ASTOB be used in avalanche mode for snubberless inductive load switching?

No - ZTX795ASTOB is not rated for repetitive avalanche operation. Its SOA curve shows no second breakdown region beyond DC and pulsed limits, and V_(BR)CEO is specified only under static conditions. For inductive flyback protection, external clamping (e.g., TVS diode across collector-emitter) is required per datasheet recommendation.

Is the ZTX795ASTOB pinout compatible with legacy TO-92 PNP transistors like BC557?

No - ZTX795ASTOB uses E-B-C pinout (Emitter-Base-Collector left-to-right, flat side facing viewer), whereas BC557 uses C-B-E. Physical insertion into a BC557 footprint will reverse emitter and collector connections, causing immediate failure. PCB layout must follow ZTX795A-specific E-Line TO-92 mechanical drawing (3-285).

Does ZTX795ASTOB meet RoHS and REACH compliance for EU industrial deployments?

Yes - ZTX795ASTOB is manufactured per Diodes Incorporated's standard RoHS-compliant process (Pb-free, halogen-free) and carries full REACH SVHC declaration. Certificate of Compliance (CoC) and material declarations are available via Diodes' official portal using part number ZTX795ASTOB and date code suffix.