Key features
Ultra-wide input voltage range: 3V to 36V
Optional mode operation
Forced PWM mode
Optional porcelain programmable PFM/PWM boundaries
300μAIC quiescent current (porcelain, no-load); 180μA Input Quiescent Current (No Load, V-OUT connected to AUXVCC)
Less than 3μA standby input current (IC for people with disabilities)
Business topology
Synchronous buck
Nonsynchronous buck
Two-stage boost and buck
Programmable frequency and frequency synchronization capability from 200kHz to 2.2MHz
±1% tight voltage regulation accuracy
Reliable overcurrent protection
Temperature compensated current sensing
Cycle-by-cycle current limit, frequency foldback
Hiccup mode for worst-case short-circuit conditions
4x4 QFN package in 20 LD
Pb-free (RoHS compliant)
description
The ISL85402 is a 125mΩ high-side MOSFET and low-side driver integrated synchronous buck controller. The ISL85402 supports a wide input voltage range of 3V to 36V. Regarding output current capability from a thermal perspective, the ISL85402 can typically support continuous loads of 2.5A, 5V output, 500kHz in the range of 8V to 30V, +85°C ambient temperature and still air under five to five conditions. For any particular application, the actual maximum output current depends on the die temperature dissipated in the IC's power supply, which is related to the input voltage, output voltage, duty cycle, switching frequency, board layout, and ambient temperature not exceeding +125°C and other reference outputs on page 13 for details. The ISL85402 has a flexible choice of operating modes in forced PWM mode and PFM mode. In PFM mode, the quiescent input current is 180μA (AUXVCC is connected to V low). The load boundary between PFM and PWM can be programmed to cover a wide range of applications. A low-side driver that can be used to drive an external low-side MOSFET for synchronous buck, or leave a standard nonsynchronous buck idle. The low-side driver can also be used to drive as a preregulator, which greatly extends the input voltage range for operation by 3V or less (refer to Typical Application Circuit Diagram III, Same IC-Controlled Buck-Boost Converter-Boost Converter). The ISL85402 provides the strongest current protection. It uses cycle-by-cycle current-limiting peak current mode control. It is implemented with frequency foldback current limiting conditions; Hiccup overcurrent protection mode, in addition to ensuring reliable operation under harsh short-term conditions. The ISL85402 provides comprehensive protection against various faults, including overvoltage and overtemperature protection