Diodes Incorporated ZDT758TC

Overview

ZDT758TC from Diodes Incorporated is a dual PNP medium-power transistor in SM-8 (SOT-223-8) package, rated for -400 V V_CEO and -0.5 A continuous collector current per die, with V_CE(sat) = -0.25 V at I_C = -50 mA/I_B = -5 mA, used in high-voltage DC-DC converter output stages and industrial relay drivers.

For engineers reviewing the ZDT758TC datasheet, ZDT758TC pinout, ZDT758TC application, or ZDT758TC equivalent, key selection criteria include breakdown voltage symmetry (-400 V V_CBO/V_CEO), dual-die thermal derating (22 mW/°C when both dies active), and h_FE = 40–50 at I_C = -100 mA for linear switching control.

Technical Context

This dual PNP device integrates two independent high-voltage transistors on a single SM-8 substrate, sharing no internal connection between dies-each has isolated C1/B1/E1 and C2/B2/E2 terminals. Its -400 V V_CEO(SUS) rating supports sustained operation under repetitive avalanche stress in flyback snubber circuits.

Thermal design requires PCB copper area ≥2 in² per die to achieve θ_JA = 45.5 °C/W (both dies active); f_T = 50 MHz at I_C = -20 mA/V_CE = -20 V enables use in <100 kHz switching topologies with controlled turn-off delay (t_off = 2000 ns).

Key Specifications

Pinout & Package

Package: SM-8 (8-lead SOT-223 variant), surface-mount, thermally enhanced with exposed die pad. Dual isolated transistor structure: Die 1 (C1, B1, E1) and Die 2 (C2, B2, E2) share no internal connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZDT758TC, ZXT758MC trades 100 V breakdown headroom and 20% h_FE for lower unit cost, while DMT3005LSD sacrifices integration density and thermal coupling benefits to reduce package complexity and enable single-die replacement flexibility.

Availability

ZDT758TC is available at Aetrix Electronics and suitable for industrial relay drivers, high-voltage DC-DC converters, capacitor discharge ignition systems, and high-voltage sensor bias supplies requiring stable component supply across extended temperature ranges.

Supply support for ZDT758TC 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.

ZDT758TC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for ruggedized industrial power control where reliability under repetitive avalanche stress and thermal predictability are primary design goals.

FAQ

What is the maximum allowable junction temperature for ZDT758TC?

The absolute maximum junction temperature is +150°C, consistent with its specified operating temperature range of -55°C to +150°C. This limit applies regardless of whether one or both dies are active, and must be verified using θ_JA = 45.5 °C/W (both dies) and actual PCB copper area.

Can ZDT758TC be used in linear amplifier configurations?

Yes-its h_FE = 40–50 at I_C = -100 mA and V_CE = -10 V, combined with low V_CE(sat), supports Class-A and Class-AB linear operation in high-voltage analog stages such as HV op-amp output buffers and precision current sources.

Is the SM-8 package lead-free and RoHS compliant?

Yes-ZDT758TC is manufactured in a lead-free, RoHS-compliant SM-8 package per Diodes Incorporated's standard qualification, with matte tin plating and halogen-free molding compound meeting JEDEC J-STD-020 and IPC/JEDEC J-STD-033 requirements.

How does thermal performance differ when only one die is active?

When only one die operates, θ_JA degrades to 55.6 °C/W and derating is 18 mW/°C-meaning total power must be reduced by ~22% versus dual-die operation to maintain the same junction temperature, due to reduced heat-spreading efficiency across the shared die pad.