Diodes Incorporated ZTX755

Overview

ZTX755 from Diodes Incorporated is a PNP silicon planar medium-power bipolar junction transistor (BJT) designed for linear amplification and medium-current switching in industrial control and power management circuits. It features −150 V V_CEO, −1 A continuous collector current, 1 W power dissipation at 25°C, low −0.5 V V_CE(sat) at −1 A/−200 mA drive, and operates across −55°C to +200°C junction temperature range.

For engineers reviewing the ZTX755 datasheet, ZTX755 pinout, ZTX755 application, or ZTX755 equivalent, key selection criteria include verified PNP polarity, TO-92-compatible E-Line package compatibility, guaranteed −150 V breakdown rating, saturation performance under high-current switching, and thermal stability in sustained conduction mode.

Technical Context

The ZTX755 is a discrete PNP BJT optimized for medium-power analog and switching applications where high voltage blocking and controlled gain are required. Its h_FE ranges from 20 to 50 at −1 A, with f_T = 30 MHz at −10 mA, supporting audio-frequency amplification and moderate-speed switching up to ~100 kHz.

It exhibits low leakage (ICBO ≤ −100 nA at −125 V), tight V_BE(sat) = −1.1 V at −500 mA/−50 mA, and robust safe operating area (SOA) up to 1 A DC with derating above 25°C ambient - enabling reliable use in relay drivers, power supply error amplifiers, and overvoltage protection stages.

Key Specifications

Pinout & Package

Package: E-Line TO-92 compatible (3-lead plastic package, same footprint as standard TO-92 but with modified lead form for automated insertion).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP medium-power transistor applications.

Compared with ZTX753 and BC327-40, the ZTX755 uniquely balances −150 V blocking, −1 A current, and −0.5 V saturation in a TO-92-compatible package - making it the only option among the three qualified for industrial 100 VDC bus monitoring and relay driving with flyback immunity.

Availability

ZTX755 is available at Aetrix Electronics and suitable for industrial relay drivers, linear regulator error amplifiers, overvoltage protection circuits, and DC motor half-H-bridge stages requiring stable component supply and long-term manufacturability.

Supply support for ZTX755 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 Taiwan and China.

The ZTX series targets medium-power discrete applications demanding high-voltage PNP/NPN transistors with enhanced thermal and SOA performance for industrial and automotive subsystems.

FAQ

Is ZTX755 RoHS compliant and halogen-free?

Yes, ZTX755 meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. The E-Line TO-92 package uses matte tin-plated leads and environmentally compliant molding compound, with full material declarations available in Diodes Incorporated's PPAP documentation.

Can ZTX755 replace ZTX754 in existing designs?

Yes, ZTX755 is a direct upgrade to ZTX754 with identical pinout, package, and thermal characteristics, but offers −150 V V_CEO (vs. −125 V) and tighter V_CE(sat) specification. No layout or drive circuit changes are needed, and it improves surge margin in relay and protection applications.

What is the maximum allowable base current for continuous operation?

The absolute maximum peak pulse base current is −2 A, but for continuous DC operation, I_B must be limited to −200 mA to maintain −1 A I_C within SOA limits and avoid thermal runaway. Derating is required above 25°C ambient per the published thermal resistance curve.

Does ZTX755 require a heatsink in 1 W operation?

At 25°C ambient and 1 W dissipation, the junction temperature reaches ~175°C using the specified R_θJA = 125°C/W. A minimal copper pad (≥1 cm²) is mandatory; for sustained operation above 50°C ambient or >500 mW, a dedicated heatsink or forced airflow is required to stay within the −55°C to +200°C T_j range.