Diodes Incorporated ZDT694TC

Overview

ZDT694TC from Diodes Incorporated is a dual NPN medium-power high-gain transistor in SM-8 (SOT-223-8) package, rated for 120V V_CEO, 0.5A continuous collector current, and minimum h_FE of 400 at 200mA. It serves as a robust switching or linear amplification device in automotive power supplies and industrial control interfaces requiring high breakdown voltage and AEC-Q101 reliability.

For engineers reviewing the ZDT694TC datasheet, ZDT694TC pinout, ZDT694TC application, or ZDT694TC equivalent, key selection criteria include its dual-die thermal derating behavior, R_θJA of 55.6°C/W (single die), V_CE(sat) ≤ 0.25V at 0.1A/0.5mA, and compliance with halogen-free, RoHS, and PPAP requirements for automotive-grade production.

Technical Context

This dual NPN transistor integrates two electrically isolated silicon die in a single SM-8 thermally enhanced leadframe package. Each die supports independent operation with identical absolute maximum ratings: 120V V_CBO/V_CEO, 0.5A I_C, and 2.25W P_D (single die active).

Its high DC current gain (h_FE ≥ 400 @ I_C = 200mA, V_CE = 2V) enables low-base-drive switching in relay drivers and motor control stages, while f_T = 130MHz supports moderate-frequency amplification up to ~10MHz with stable gain.

Key Specifications

Pinout & Package

Package: SM-8 (8-lead SOT-223 variant), molded plastic with UL 94V-0 rating, matte tin-plated leads, 0.117g weight. Thermal path optimized via exposed collector leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZXTN2010Z and MBT3904DW1T1G, ZDT694TC uniquely delivers dual 120V/0.5A NPN channels with AEC-Q101 validation and thermal performance optimized for PCB-mounted power dissipation - making it irreplaceable in automotive and industrial 24–48V switching applications requiring reliability and headroom.

Availability

ZDT694TC is available at Aetrix Electronics and suitable for automotive lighting systems, industrial PLC I/O modules, DC-DC auxiliary supplies, and motor control feedback circuits requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZDT694TC 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, manufacturing, and sales operations across Asia, Europe, and North America.

ZDT694TC belongs to Diodes' high-reliability bipolar transistor product line, engineered specifically for automotive and industrial power interface applications demanding AEC-Q101 qualification, high-voltage tolerance, and thermally robust packaging.

FAQ

What is the thermal relationship between the two NPN transistors in the ZDT694TC?

The two NPN die share a common collector leadframe (Pins 1–3 and 8), resulting in coupled thermal resistance. When both die operate simultaneously, R_θJA degrades from 55.6°C/W to 45.5°C/W, and total P_D is limited to 2.75W. Designers must apply derating curves from the datasheet's Figure 3 to ensure junction temperature remains below 150°C under combined load conditions.

Can ZDT694TC be used in linear amplifier configurations?

Yes - its f_T = 130MHz, h_FE ≥ 400, and low V_CE(sat) support Class-A and Class-AB small-signal amplification up to ~10MHz. However, linear operation requires strict adherence to SOA limits (Figure 4), especially pulse-width-dependent power constraints, and careful attention to base bias stability due to gain variation with temperature.

Is the SM-8 package compatible with standard SOT-223 reflow profiles?

Yes - the SM-8 package is JEDEC-compliant and rated for moisture sensitivity Level 1. It supports standard lead-free reflow profiles (peak 260°C, 60s above 217°C) per J-STD-020. The exposed collector pad requires solder paste coverage matching Diodes' AP02001 recommended pad layout to ensure mechanical reliability and thermal performance.

Does ZDT694TC support parallel operation of both transistors for higher current?

No - the two NPN transistors are electrically isolated but thermally coupled. Parallel operation without individual current-sharing resistors risks thermal runaway due to h_FE mismatch and shared R_θJA. For >0.5A loads, use one transistor per channel with independent base drive and thermal management per the Safe Operating Area curves in the datasheet.