Diodes Incorporated ZTX968STOA

Overview

ZTX968STOA from Diodes Incorporated is a PNP silicon planar medium-power high-current transistor rated for -4.5 A continuous collector current, -12 V V_CEO, and -220 mV V_CE(sat) at I_C = -5 A / I_B = -200 mA. It delivers high DC current gain (h_FE = 300 min at I_C = -10 mA) and operates across -55°C to +200°C, commonly used in industrial power switching and linear regulator pass elements.

For engineers reviewing the ZTX968STOA datasheet, ZTX968STOA pinout, ZTX968STOA application, or ZTX968STOA equivalent, key selection criteria include verified PNP polarity, TO-92-compatible E-Line package thermal resistance (R_th(j-amb) = 150°C/W), saturation voltage under high-current drive, and safe operating area compliance at elevated junction temperatures.

Technical Context

This device is a discrete bipolar junction transistor optimized for medium-power linear and switching applications where low V_CE(sat) and stable h_FE over wide current ranges (-10 mA to -5 A) are critical. Its -12 V V_CEO rating and -20 A peak pulse capability support robust operation in relay drivers and power supply error amplifiers.

The ZTX968STOA features a Spice model for simulation validation and exhibits f_T = 80 MHz at I_C = -100 mA, enabling use in moderate-speed switching circuits. Its C_obo = 161 pF at V_CB = -20 V supports predictable turn-off behavior in inductive load control.

Key Specifications

Pinout & Package

Package: E-Line TO-92 compatible (3-lead plastic case, lead-forming option STOA denotes straight leads, tinned, axial orientation).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX968STOA, ZTX951STOA trades current capability for higher voltage tolerance, while MJD2955G offers superior thermal performance at the cost of package size and simulation support-selection depends on voltage headroom, thermal budget, and design verification requirements.

Availability

ZTX968STOA is available at Aetrix Electronics and suitable for industrial power supply regulation, DC motor direction control, and overcurrent protection circuits requiring stable component supply and consistent parametric performance across production batches.

Supply support for ZTX968STOA 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, computing, and consumer markets.

The ZTX series targets medium-power discrete applications demanding proven ruggedness, wide temperature operation, and validated SPICE models-designed specifically for power management, protection, and interface functions in mission-critical systems.

FAQ

What is the maximum safe continuous collector current for ZTX968STOA at 75°C ambient?

At T_amb = 75°C, derating per the thermal curve yields ~0.8 W max dissipation. With V_CE(sat) ≈ -150 mV at I_C = -2 A, power loss remains below 0.3 W. Thus, -4.5 A continuous rating holds only with adequate PCB copper area (≥1 inch²) and airflow; sustained operation above 60°C ambient requires thermal modeling.

Does ZTX968STOA support parallel operation for higher current handling?

Parallel operation is not recommended without external emitter resistors due to negative temperature coefficient of V_BE(sat), which causes current hogging. The datasheet does not specify matching tolerances or recommend paralleling. For >4.5 A, use a single higher-rated device like MJD2955G instead.

Is the ZTX968STOA RoHS compliant and halogen-free?

Yes. Diodes Incorporated confirms ZTX968STOA meets RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. The "STOA" suffix indicates lead-free, matte-tin plated leads and green molding compound compliant with IPC-4101D/126.

Can ZTX968STOA replace ZTX953 in existing designs?

No-ZTX953 is an NPN transistor (V_CEO = +100 V, I_C = +1.5 A), making it electrically incompatible with ZTX968STOA's PNP polarity and complementary biasing scheme. Direct substitution would invert logic and cause circuit failure; redesign of bias network and signal path is required.