Diodes Incorporated ZTX953

Overview

ZTX953 from Diodes Incorporated is a PNP silicon planar medium-power high-current transistor with confirmed V_CEO = −100 V, I_C = −3.5 A continuous, V_CE(sat) = −140 mV at I_C = −2 A / I_B = −200 mA, h_FE = 90 at I_C = −3 A, and f_T = 125 MHz - used in industrial DC-DC converter output stages requiring low-loss switching and robust thermal performance.

For engineers reviewing the ZTX953 datasheet, ZTX953 pinout, ZTX953 application, or ZTX953 equivalent, key selection criteria include verified PNP polarity, TO-92 package compatibility, −100 V V_CEO rating, sub-200 mV saturation voltage under 2 A load, and gain stability up to 10 A peak current - critical for high-reliability linear and switching power control designs.

Technical Context

The ZTX953 operates as a medium-power PNP bipolar junction transistor optimized for high-current linear regulation and hard-switching applications. Its structure delivers low V_CE(sat) (−140 mV @ −2 A) and stable h_FE (≥90 @ −3 A), enabling efficient current sourcing in emitter-follower configurations.

Thermal design is supported by R_th(j–amb) = 150 °C/W (PCB-mounted) and R_th(j–case) = 50 °C/W, with safe operating area validated up to 10 A peak pulse and −100 V collector-emitter blocking - suitable for non-isolated buck regulators and motor drive pre-driver stages.

Key Specifications

Pinout & Package

Package: TO-92 (E-Line compatible, 3-318 outline), lead-forming option available. Mounting requires ≥1 inch² copper pour for rated P_tot = 1.2 W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-current transistor applications.

Compared with MJD2955 and BC807-40, the ZTX953 uniquely balances −100 V blocking, −3.5 A continuous rating, and TO-92 compatibility - making it optimal for space-constrained 2–3 A industrial power stages where thermal mass and voltage margin are both critical.

Availability

ZTX953 is available at Aetrix Electronics and suitable for industrial DC-DC converters, linear voltage regulators, and motor driver pre-drivers requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for ZTX953 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 company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The ZTX953 belongs to Diodes' high-reliability bipolar transistor product line, engineered for industrial and automotive power control where robustness, thermal resilience, and consistent gain at high current are mandatory.

FAQ

Is the ZTX953 RoHS compliant and halogen-free?

Yes, the ZTX953 meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. Diodes Incorporated's official documentation confirms compliance for all standard production lots, with material declarations available upon request for traceability in regulated industries.

What is the maximum allowable PCB copper area for full 1.2 W power dissipation?

Full 1.2 W continuous dissipation requires ≥1 inch² of 2 oz copper on the component side, directly connected to the emitter pad. Thermal vias to inner-layer ground planes further reduce R_th(j–amb) by ~25%, but the datasheet specifies 1 inch² minimum as baseline for rated P_tot.

Can the ZTX953 be used in avalanche mode?

No - the ZTX953 is not rated or characterized for repetitive avalanche operation. Its safe operating area curve excludes secondary breakdown beyond rated V_CEO, and no avalanche energy (E_AS) specification is provided. Use external clamping for inductive load switching.

Does the ZTX953 SPICE model include thermal coupling and temperature-dependent parameters?

Yes, the official Diodes Incorporated SPICE model for ZTX953 includes temperature-dependent β, V_BE, and saturation resistances, along with thermal network elements (R_th, C_th) matching the published transient impedance curves - validated against measured junction temperature rise under pulsed conditions.