|Intersil's ISL85402 is a synchronous buck controller with a 125 mΩ high-side MOSFET and low-side driver integrated. The ISL85402 supports a wide input voltage range from 3 V to 36 V. Regarding the output current capability from the thermal perspective, the ISL85402 can typically support continuous load of 2.5 A under conditions of 5 V VOUT, VIN range of 8 V to 30 V, 500 kHz, and +85°C ambient temperature with still air. For any specific application, the actual maximum output current depends upon the die temperature not exceeding +125°C with the power dissipated in the IC. This is related to input voltage, output voltage, duty cycle, switching frequency, board layout and ambient temperature.
The ISL85402 has flexible selection of operation modes including forced PWM mode and PFM mode. In PFM mode, the quiescent input current is as low as 180 µA (AUXVCC connected to VOUT). The load boundary between PFM and PWM can be programmed to cover wide applications.
The low-side driver can be either used to drive an external low-side MOSFET for a synchronous buck, or left unused for a standard non-synchronous buck. The low-side driver can also be used to drive a boost converter as a pre-regulator followed by a buck controlled by the same IC, greatly expanding the operating input voltage range down to 3 V or lower.