Diodes Incorporated ZHB6718TA

Overview

ZHB6718TA from Diodes Incorporated is a monolithic bipolar H-bridge IC integrating two NPN and two PNP transistors in a single SM-8 package, rated for 20V operation and 2.5A continuous collector current per switch. It delivers low saturation voltages (V_CE(sat) < 150 mV @ 1A for NPN; < –200 mV @ –1A for PNP) and supports bidirectional DC motor control in compact industrial actuators and automotive window lift modules.

For engineers reviewing the ZHB6718TA datasheet, ZHB6718TA pinout, ZHB6718TA application, or ZHB6718TA equivalent, key selection criteria include verified H-bridge topology, AEC-Q101 qualification, thermal resistance (R_θJA = 100°C/W), SOA derating on 50mm × 50mm FR4, and discrete BJT-level switching timing (t_ON/t_OFF ≤ 400 ns).

Technical Context

The ZHB6718TA implements a fully complementary BJT-based H-bridge with matched NPN/PNP pairs sharing common emitter connections and independent base terminals. Its internal layout enables simultaneous conduction of diagonally opposite transistors while preventing shoot-through via external logic-controlled base drive sequencing.

Thermal performance is defined under two mounting conditions: R_θJA = 100°C/W (single die active, 25mm × 25mm copper) and 62.5°C/W (dual-die active, full power sharing). Safe Operating Area curves are provided for both minimal-copper (1.5mm traces) and full-copper PCB layouts at DC and pulsed (100μs/1ms) conditions.

Key Specifications

Pinout & Package

Package: SM-8 (8-lead SOT-223 variant), molded green plastic, UL 94V-0 rated, 0.117 g mass. Lead finish: matte tin, solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK682-050-E and TB6612FNG, the ZHB6718TA uniquely balances AEC-Q101 compliance, 2.5A/20V bipolar performance, and SM-8 compactness-making it optimal for automotive and space-constrained industrial H-bridge applications where discrete BJT control and thermal predictability are prioritized.

Availability

ZHB6718TA is available at Aetrix Electronics and suitable for automotive power window modules, industrial linear actuators, medical infusion pumps, and robotics joint drivers requiring stable component supply and long-term lifecycle support.

Supply support for ZHB6718TA 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 semiconductor company specializing in discrete, analog, and mixed-signal devices, with manufacturing and test facilities across Asia and North America.

The ZHB6718TA belongs to Diodes' automotive-qualified bipolar power transistor family, engineered for robust, thermally efficient H-bridge motor control in safety-critical and high-reliability environments.

FAQ

What base drive current is required to saturate the ZHB6718TA at 2.5A output?

For NPN transistors, h_FE ≥200 at I_C = 2.5A, so minimum base current is 12.5 mA; typical design uses 50 mA to ensure deep saturation and low V_CE(sat). For PNP transistors, h_FE ≥150 at I_C = –2.5A, requiring ≥16.7 mA base current; datasheet recommends –200 mA for guaranteed performance under worst-case h_FE and temperature.

Can the ZHB6718TA be used in PWM motor control above 20 kHz?

Yes-the PNP t_ON is ≤40 ns and t_OFF ≤670 ns, while NPN t_OFF is ≤400 ns. At 20 kHz (50 μs period), switching losses remain manageable if dead time exceeds 1 μs. However, full 2.5A current should be limited to ≤10 kHz for thermal stability unless PCB copper area exceeds 50 mm × 50 mm.

Does the ZHB6718TA include internal protection features like overtemperature shutdown?

No-the ZHB6718TA is a bare-bones bipolar H-bridge with no integrated protection circuitry. External solutions are required: base current limiting resistors, flyback diodes across the motor, and optional external thermal monitoring via PCB copper temperature sensing or dedicated ICs such as the TMP300.

How does the SM-8 package compare thermally to standard SOT-223 for this device?

The SM-8 is an 8-lead variant of SOT-223 with two additional emitter leads and optimized internal leadframe geometry. Its R_θJL is 62°C/W-lower than typical SOT-223 (≈80°C/W)-due to dual emitter paths and enhanced thermal coupling to PCB copper. This enables 2× power handling versus standard SOT-223 when mounted on identical board area.