Diodes Incorporated ZHB6790TA

Overview

ZHB6790TA from Zetex (now Diodes Incorporated) is a monolithic H-bridge bipolar transistor array comprising two NPN and two PNP transistors in a single SM-8 (SOT-223-8) package, designed for bidirectional DC motor control and load switching. It supports 40 V supply, delivers 2 A continuous collector current per transistor, exhibits V_CE(sat) as low as 0.1 V (NPN) and –0.14 V (PNP) at 100 mA, and operates from –55 °C to +150 °C.

For engineers reviewing the ZHB6790TA datasheet, ZHB6790TA pinout, ZHB6790TA application, or ZHB6790TA equivalent, key selection criteria include verified dual-pair conduction capability (Q1/Q3 or Q2/Q4), thermal resistance of 62.5 °C/W under dual-transistor-on condition, safe operating area validation for 100 µs–1 s pulses, and confirmed SM-8 footprint compatibility with 50 mm × 50 mm FR4 PCB copper layout.

Technical Context

The ZHB6790TA integrates complementary NPN/PNP pairs optimized for synchronous H-bridge operation: Q1/Q4 and Q2/Q3 form opposing switch legs, enabling four-quadrant control without external cross-conduction protection circuitry. Each transistor features independent base terminals (B1–B4) and shared emitter/collector groupings (E1/E4, E2/E3, C1/C2, C3/C4), supporting discrete gate drive and current-sense node access.

Thermal design is defined by dual-mode power derating: 1.25 W for any single transistor "on", and 2 W when opposing pairs (Q1+Q3 or Q2+Q4) conduct simultaneously-reflecting its intended use case. Transient thermal resistance curves are provided for pulse widths from 100 µs to 100 s, calibrated to both full-copper and minimum-copper PCB mounting conditions.

Key Specifications

Pinout & Package

Package: SM-8 (8-lead SOT-223 variant), 6.3–6.7 mm × 3.3–3.7 mm body, 1.7 mm height, with exposed thermal pad (pin 5) tied to internal collector common planes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar H-bridge transistor array applications.

Compared with NSS40501MR6T1G and ZXBM5210, ZHB6790TA uniquely provides monolithic, thermally coupled NPN/PNP pairs with verified dual-transistor SOA and SPICE-model-supported design-making it optimal for cost-sensitive, high-reliability discrete H-bridge implementations where drive logic is already implemented externally.

Availability

ZHB6790TA is available at Aetrix Electronics and suitable for industrial motor control, automotive seat/mirror actuation, and PLC output modules requiring stable component supply, long-lifecycle support, and validated thermal performance on standard FR4 PCBs.

Supply support for ZHB6790TA 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

Zetex plc (acquired by Diodes Incorporated in 2008) was a UK-based designer of high-performance analog and discrete semiconductors, known for innovation in bipolar and RF devices.

The ZHB6790TA belongs to Zetex's monolithic H-bridge transistor family, engineered specifically for compact, thermally robust DC load switching in industrial and automotive environments where discrete transistor matching and PCB-level thermal management are critical.

FAQ

What is the maximum continuous current rating per transistor in the ZHB6790TA?

The ZHB6790TA supports 2 A continuous collector current per transistor when mounted on a 50 mm × 50 mm FR4 PCB with full copper coverage and operated at T_amb = 25 °C. Derating applies above 25 °C at 16 mW/°C for dual-pair operation (Q1+Q3 or Q2+Q4), and the absolute maximum junction temperature is 150 °C.

Does the ZHB6790TA include internal protection features such as overtemperature shutdown or current limiting?

No-the ZHB6790TA is a bare bipolar transistor array with no integrated protection circuitry. It relies on external base drive control, PCB copper thermal mass, and system-level monitoring (e.g., current sense resistors, microcontroller ADC feedback) for safe operation. Its Safe Operating Area (SOA) charts define the voltage-current-time boundaries within which it can operate without secondary breakdown.

Can the ZHB6790TA be used with 5 V logic-level microcontrollers directly?

No-base drive must be calculated per transistor. At 2 A I_C, required base current is 30 mA (NPN) or –50 mA (PNP). Standard 5 V GPIO cannot source/sink this; a dedicated base driver (e.g., ULN2003 for NPN, UDN2981 for PNP) or discrete buffer stage is mandatory to ensure saturation and avoid thermal runaway.

Is the thermal pad (Pin 5) electrically isolated or internally connected?

Pin 5 is the exposed thermal pad and is internally connected to all four collector nodes (C1, C2, C3, C4). It must be soldered to a large copper pour tied to the positive supply rail (for NPN collectors) or ground (if PNP collectors are referenced to GND), and cannot be left floating or grounded independently without violating voltage isolation between transistor sections.