ISL85402

Support is limited to customers who have already adopted these products.

The ISL85402 is a synchronous buck controller with a 125mΩ high-side MOSFET and low-side driver integrated. The ISL85402 supports a wide input range of 3V to 36V in buck mode. It supports 2.5A continuous load under conditions of 5V V_OUT, V_IN range of 8V to 36V, 500kHz and +105°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, which is related to input voltage, output voltage, duty cycle, switching frequency, board layout and ambient temperature, etc. Refer to “Output Current” on page 14 for more details. The ISL85402 has a flexible selection of operation modes of forced PWM mode and PFM mode. In PFM mode, the quiescent input current is as low as 180µA (AUXVCC connected to V_OUT). 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, which greatly expands the operating input voltage range down to 2.5V or lower (Refer to “Typical Application Schematic III - Boost Buck Converter” on page 5). The ISL85402 offers the most robust current protections. It uses peak current mode control with cycle-by-cycle current limiting. It is implemented with frequency foldback under current limit condition; besides that, the hiccup overcurrent mode is also implemented to guarantee reliable operations under harsh short conditions. The ISL85402 has comprehensive protections against various faults including overvoltage and over-temperature protections, etc.