Diodes Incorporated ZTX795ASTZ

Overview

ZTX795ASTZ 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 converter feedback stages and relay drivers.

For engineers reviewing the ZTX795ASTZ datasheet, ZTX795ASTZ pinout, ZTX795ASTZ application, or ZTX795ASTZ 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 BJT operates in common-emitter configuration with fixed-current gain characteristics optimized for medium-speed switching (t_on = 100 ns, t_off = 1900 ns) and analog amplification. Its f_T = 100 MHz at I_C = −50 mA / V_CE = −5 V supports stable RF pre-driver use up to VHF band edges.

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 suitability for heatsink-assisted mounting in regulated power supplies.

Key Specifications

Pinout & Package

Package: TO-92-compatible E-Line (3-lead, straight lead form, epoxy molded). Pin identification follows standard BJT orientation: viewed from flat side with leads down, left-to-right is Emitter (E), Base (B), Collector (C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX753, ZTX795ASTZ adds 40 V breakdown margin and 25% higher gain for improved noise immunity in noisy industrial environments; versus MJD2955T4G, it trades raw current capacity for compact size and lower system-level thermal overhead in sub-ampere applications.

Availability

ZTX795ASTZ is available at Aetrix Electronics and suitable for industrial relay drivers, DC-DC converter feedback circuits, high-voltage sensor interfaces, and automotive engine control modules requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for ZTX795ASTZ 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for industrial, computing, consumer, and communications markets.

ZTX795ASTZ belongs to the ZTX high-voltage BJT product line, engineered for ruggedized linear and switching applications where breakdown voltage, gain consistency, and thermal resilience are prioritized over ultra-high speed or RF optimization.

FAQ

Is ZTX795ASTZ RoHS compliant and halogen-free?

Yes. ZTX795ASTZ meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. The device uses lead-free matte tin plating on leads and complies with JEDEC J-STD-020 moisture sensitivity level (MSL) 1 for unlimited floor life at ≤30°C/85% RH.

Can ZTX795ASTZ replace ZTX795A in existing designs?

Yes - ZTX795ASTZ is a direct replacement for ZTX795A. Both share identical electrical specifications, TO-92-compatible E-Line packaging, pinout (E-B-C), and thermal ratings. The "STZ" suffix denotes tape-and-reel packaging for automated assembly; no circuit or layout changes are required.

What is the recommended PCB layout for optimal thermal performance?

Mount ZTX795ASTZ on FR-4 with ≥1 in² (2.54 cm²) of 2-oz copper connected directly to the collector pad. Use thermal vias (≥4 × 0.3 mm diameter) under the collector pad to inner ground planes. Keep base/emitter traces short and avoid routing high-dI/dt signals near the base connection to minimize switching noise coupling.

Does ZTX795ASTZ require a base resistor in switching applications?

Yes. A base resistor is mandatory to limit I_B and ensure proper saturation. For I_C = −500 mA and h_FE = 250, minimum I_B = −2 mA is required. With V_BE(sat) = −0.95 V and 3.3 V logic drive, a 1.2 kΩ resistor delivers −2.0 mA, achieving reliable saturation while preventing excessive base current during transients.