Diodes Incorporated ZTX718STOA

Overview

ZTX718STOA from Diodes Incorporated (formerly Zetex) is a PNP silicon planar medium-power high-gain bipolar junction transistor, designed for switching and linear amplification in power control stages. It delivers 2.5A continuous collector current, -20V V_CEO, low V_CE(sat) down to -145mV at IC = -1.5A/IB = -50mA, and h_FE ≥ 300 at IC = -10mA - enabling robust gate driving of power MOSFETs in DC-DC converters.

For engineers reviewing the ZTX718STOA datasheet, ZTX718STOA pinout, ZTX718STOA application, or ZTX718STOA equivalent, key selection criteria include verified pulsed I_CM = -6A capability, thermal resistance R_th(j-amb) = 116°C/W on 1 in² PCB copper, and guaranteed h_FE ≥ 35 at IC = -4A for high-current saturation integrity.

Technical Context

This PNP BJT operates in common-emitter configuration with fixed-polarity biasing, supporting fast-switching duty cycles ≤2% via 40ns t_on and 670ns t_off under pulsed test conditions. Its safe operating area (SOA) is defined up to T_j = +200°C, with derated P_tot = 1W at T_amb = 25°C and 0.25W at 120°C.

The device exhibits strong current gain linearity across IC = -10mA to -6A (pulsed), with h_FE = 475 (typ.) at -10mA and h_FE = 35 (min.) at -6A - critical for maintaining drive strength in high-side switch drivers where base current scaling must track load transients.

Key Specifications

Pinout & Package

Package: TO-92 (E-Line compatible), through-hole, epoxy-molded plastic case with standard lead spacing and orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD2955G and BCP53-16, ZTX718STOA uniquely balances TO-92 manufacturability, 2.5A continuous rating, and verified 6A pulsed capability - making it optimal for cost-sensitive, medium-power gate drivers where thermal mass and layout simplicity are prioritized over ultra-high voltage or current headroom.

Availability

ZTX718STOA is available at Aetrix Electronics and suitable for power MOSFET gate drivers, DC-DC converter output stages, and motor control H-bridges requiring stable component supply, consistent parametric performance, and long-term obsolescence resilience.

Supply support for ZTX718STOA 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 acquired Zetex plc in 2008 and maintains its legacy high-performance discrete portfolio, emphasizing reliability, wide temperature operation, and application-specific optimization for power management.

ZTX718STOA belongs to Zetex's medium-power bipolar transistor family, engineered specifically for high-gain, low-saturation switching in compact power interface circuits - especially where complementary PNP/NPN pairing and TO-92 manufacturability are essential.

FAQ

What is the maximum allowable base current for reliable operation?

The absolute maximum rated base current is -500mA, but continuous operation above -200mA is not recommended without thermal derating. At IC = -2.5A, the datasheet specifies IB = -200mA for saturation - exceeding this risks localized heating and h_FE degradation. Pulse operation up to -500mA is permitted only at ≤2% duty cycle and <300µs width.

Can ZTX718STOA be used in parallel configurations?

No - ZTX718STOA lacks built-in emitter ballasting resistors and exhibits significant h_FE variation (300–475 typ.), making current sharing unstable without external balancing components. Parallel use is discouraged unless individual emitter resistors (≥0.1Ω) and matched devices are employed, which negates TO-92 space advantages.

Is the ZTX718STOA RoHS compliant?

Yes - Diodes Incorporated certifies ZTX718STOA as RoHS 2011/65/EU compliant, with lead-free terminations and halogen-free molding compound. The device meets JEDEC J-STD-020 moisture sensitivity level (MSL) 1 and has been qualified per AEC-Q101 for automotive-grade reliability where applicable.

How does thermal performance change with PCB copper area?

R_th(j-amb) drops from 175°C/W (no copper) to 116°C/W with ≥1 in² of 2-oz copper - a 34% improvement. Adding thermal vias under the emitter pad further reduces resistance by ~15%, but gains diminish beyond 1.5 in². Derating curves assume minimum 1 in²; smaller layouts require strict ambient temperature limits.