Renesas Electronics introduces the 100V, 4A half-bridge N-MOSFET series of drivers for automotive applications

Renesas Electronics introduces the new 100V, 4A half-bridge N-MOSFET family of drivers for automotive applications -ISL784x4. The ISL784x4 series includes three models: ISL78424, ISL78444 (three-state level PWM input, high and low side drive output), and ISL78434 (high and low side drive independent input and output). The ISL784x4 half-bridge N-MOSFET driver complements the ISL78224 four-phase bidirectional controller, enabling it to deliver up to 3kW of power and more than 95% efficiency for 12V-48V power converters used in light hybrid vehicles. The ISL784x4 driver is also ideal for 12V-24V bi-directional DC/DC power converters, as well as other high-current buck or boost power conversion applications.

The ISL784x4 driver simplifies the drive of high-current MOSFETs by providing separate source and fill current drive pins. This allows designers to easily adjust the rise and fall rates of the DC/DC converter switching node voltage using external drive resistors, thereby reducing electromagnetic interference (EMI). The ISL784x4 also provides adaptive dead-time control to ensure accurate turn-on switching operation, preventing through current that can occur when two DC/DC converter switches are turned on at the same time. In addition, the adaptive dead-time control of the ISL78424 and ISL78434 detects voltage at the MOSFET's gate, eliminating potential drive voltage detection errors due to voltage drops on the drive resistance.

The ISL784x4 series drivers are ideal for high-current DC/DC power converter applications, such as 12-48V power converters for 48V light hybrid vehicles. They increase efficiency by providing a powerful drive capability with 3A peak source current and 4A peak perfusion current. The powerful gate drive capability enables them to quickly switch high-current MOSFETs with large gate capacitors, thereby reducing switching losses.

Adaptive dead-time control of half-bridge MOSFET drivers minimizes excess dead-time, thereby reducing conduction losses and further improving the conversion efficiency of DC/DC power supplies. In addition, the ISL784x4 series drivers offer voltage ratings for 48V automotive systems, for which the switching nodes can withstand 70V DC and transient voltages of up to 86V infrequently. Similarly, the bootstrap node of the high-side driver can withstand 86V DC voltage and transient voltages up to 100V.

Akira Daiichi, Vice President, Automotive Systems Project Management, Renesas Electronics, said: "Our new ISL784x4 series half-bridge driver is the first driver product to combine adaptive dead-time control for gate voltage detection with independent source and fill current drive control. The highly integrated ISL78424, ISL78434 and ISL78444 offer several of the best features in their class, outperforming competing half-bridge drives while providing our customers with the best performance and ease of use."

Key features of ISL78424, ISL78434, and ISL78444:

● 3A source current /4A perfusion current drive output
● Three-state level PWM input (ISL78424 and ISL78444)
● Independent HI/LI drive input (ISL78434)
● Independent source current and perfusion current drive output (ISL78424 and ISL78434)
● Wide supply voltage range from 8V to 18V
● Integrated 3Ω bootstrap FET switch without external Schottky diode
● Single resistance control adjusts self-adaptive dead zone time
● Complies with AEC-Q100 Class 1 standard, operating temperature range from -40°C to + 140°C

The ISL78424 and ISL78444, which use three-state level PWM signals, can be combined with the ISL78224 four-phase bidirectional synchronous PWM controller for power conversion between 12V and 48V buses in 48V light hybrid vehicles. Designers can also use Renesas' RH850 microcontroller for ASIL safety monitoring, system control and vehicle communication. The ISL78424 and ISL78444 can also be combined with the ISL78225 four-phase controller or the ISL78220 six-phase controller to enable power design for automotive audio amplifiers.