Diodes Incorporated ZTX758STOA

Overview

ZTX758STOA from Diodes Incorporated is a PNP medium-power high-voltage transistor in E-Line (TO-92 compatible) package, rated for -400V V_CEO, -0.5A continuous collector current, and 1W power dissipation at +25°C ambient. It operates up to +200°C junction temperature and features low saturation voltage of -250mV at -50mA/-5mA drive, making it suitable for high-voltage switching in industrial power supplies and relay drivers.

For engineers reviewing the ZTX758STOA datasheet, ZTX758STOA pinout, ZTX758STOA application, or ZTX758STOA equivalent, key selection criteria include its -400V breakdown rating, AEC-Q101 qualification, thermal resistance of 175°C/W (min pad layout), and verified E-Line mechanical compatibility with TO-92 footprints in through-hole power control designs.

Technical Context

This PNP bipolar junction transistor is optimized for high-voltage linear and switching operation in DC-DC converters, lamp ballasts, and solenoid/relay interface circuits. Its BV_CEO = -400V and BV_CBO = -400V support robust isolation in off-state conditions, while h_FE = 50–400 across IC = -1mA to -200mA enables stable current amplification in base-driven configurations.

Thermal design is supported by R_θJA = 175°C/W under minimum recommended PCB layout and R_θJL = 70°C/W to collector lead, enabling reliable operation at T_J up to +200°C. ESD ratings meet JEDEC Class 3A HBM (≥4kV) and MM (≥400V), confirming suitability for assembly environments with moderate static control.

Key Specifications

Pinout & Package

E-Line (TO-92 compatible) package with molded green plastic case, matte tin-plated leads, and UL 94V-0 flammability rating. Weight: 0.159g. Seating plane defined at bottom of package; collector lead extends 13.0–13.97mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX758STOA, ZTX753 trades voltage headroom for smaller size and cost, while MJD2955T4G sacrifices voltage rating for tenfold current capacity and thermal mass-neither is pin-compatible, requiring layout revision.

Availability

ZTX758STOA is available at Aetrix Electronics and suitable for industrial power supply control, automotive relay interface, lamp ballast preheat circuits, and industrial solenoid driver applications requiring stable component supply with AEC-Q101 reliability assurance.

Supply support for ZTX758STOA 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 automotive, industrial, and computing markets.

The ZTX series targets medium-power bipolar transistors for high-voltage switching and linear regulation, emphasizing ruggedness, thermal stability, and AEC-Q101 compliance in compact through-hole packages.

FAQ

What is the maximum safe operating voltage for ZTX758STOA in continuous DC applications?

The ZTX758STOA is rated for V_CEO = -400V and V_CBO = -400V under DC conditions at T_A = +25°C. For reliable long-term operation, design voltage stress should remain ≤80% of rated value (i.e., ≤-320V) to accommodate transients and temperature derating. Derating curves in DS33299 show linear reduction to -200V at +125°C ambient.

Can ZTX758STOA replace a standard TO-92 PNP transistor like BC557 in existing layouts?

Yes-ZTX758STOA uses the E-Line package, which is mechanically identical to TO-92 (same pin spacing, lead diameter, and body dimensions per AP02002). Pinout is E-C-B (emitter-collector-base) when viewed from flat side with leads down, matching BC557 orientation. Electrical differences (higher voltage, lower h_FE at high current) require circuit validation but no footprint change.

How does the -250mV V_CE(sat) specification translate to real-world power loss?

At I_C = -50mA and I_B = -5mA, V_CE(sat) = -250mV yields conduction power loss of 12.5mW (P = V × I). This enables operation without heatsinking below 100mA loads on standard FR4, even at +70°C ambient. Loss rises to 50mW at -200mA, triggering thermal derating per the 175°C/W R_θJA curve.

Is ZTX758STOA suitable for pulse-width modulated (PWM) switching above 10kHz?

Yes-its f_T = 50MHz and documented turn-on/off times (t_on = 140ns, t_off = 2000ns) support PWM operation up to ~100kHz with acceptable switching loss. However, t_off dominates total cycle time; for >50kHz, ensure gate/base drive strength exceeds -10mA to minimize storage time and avoid secondary breakdown during transition.