Diodes Incorporated ZTX953STOB

Overview

ZTX953STOB from Diodes Incorporated is a PNP silicon planar medium-power high-current transistor rated for −3.5 A continuous collector current, −100 V V_CEO, and −140 V V_CBO, with V_CE(sat) as low as −140 mV at I_C = −2 A / I_B = −200 mA. It delivers excellent DC current gain (h_FE = 200 min at I_C = −1 A) and operates from −55°C to +200°C junction temperature, used in industrial power switching and linear regulator pass elements.

For engineers reviewing the ZTX953STOB datasheet, ZTX953STOB pinout, ZTX953STOB application, or ZTX953STOB equivalent, key selection criteria include verified PNP polarity, TO-92-compatible E-Line package thermal resistance (R_th(j-amb) = 150°C/W), low saturation voltage under high-current drive, and documented safe operating area up to 10 A pulsed.

Technical Context

This PNP bipolar junction transistor employs a planar epitaxial structure optimized for medium-power linear and switching operation. Its design supports high-current capability with low V_CE(sat) across I_C = −100 mA to −4 A and maintains usable h_FE ≥ 50 even at I_C = −4 A under V_CE = −1 V.

Thermal performance is defined by R_th(j-case) = 50°C/W and R_th(j-amb) = 150°C/W on 1-inch² PCB copper, enabling stable operation up to +200°C junction temperature. Switching times (t_on = 110 ns, t_off = 460 ns) are specified at I_C = −2 A with forced β = 1.

Key Specifications

Pinout & Package

Package: TO-92-compatible E-Line (3-318), molded plastic case with leads arranged in straight-line configuration. Standard lead finish is matte tin; device is RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX951STOB, ZTX953STOB provides 40% higher continuous current and 44% lower V_CE(sat) at 2 A, while MJD2955G trades compactness and speed for vastly superior power handling-making ZTX953STOB optimal for mid-power, space-limited PNP switching.

Availability

ZTX953STOB is available at Aetrix Electronics and suitable for industrial linear regulators, high-side load switches, motor pre-drivers, and overcurrent protection circuits requiring stable component supply and extended temperature operation.

Supply support for ZTX953STOB 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, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Malaysia, and Taiwan.

ZTX953STOB belongs to the ZTX series of high-reliability bipolar transistors engineered for industrial power control and ruggedized linear applications demanding wide temperature range and proven robustness.

FAQ

Is ZTX953STOB suitable for surface-mount assembly?

No. ZTX953STOB uses a through-hole E-Line TO-92-compatible package with straight leads designed for axial insertion and wave soldering. It lacks SMT-compatible terminations or land patterns, and its thermal performance is validated only for PCB-mounted copper area, not reflow profiles.

What is the maximum safe operating voltage with resistive base drive?

The absolute maximum V_CEO is −100 V with base open. With resistive base drive, safe operation requires ensuring V_EB does not exceed −6 V and that base current remains within −100 mA to −400 mA range per datasheet test conditions to avoid second breakdown.

Does ZTX953STOB have built-in ESD protection?

No. The ZTX953STOB is an unprotected bipolar transistor with no integrated ESD structures. Per datasheet Absolute Maximum Ratings, V_EB must not exceed −6 V, and handling requires standard static-sensitive device precautions including grounded workstations and ionized air.

Can ZTX953STOB replace ZTX953 in existing designs?

Yes. ZTX953STOB is a direct revision of ZTX953 with identical electrical specifications, pinout, and package dimensions. The "STOB" suffix denotes tape-and-reel packaging and compliance with updated environmental standards (RoHS/halogen-free), with no functional or parametric changes.