The ISL6237 dual step-down, switch-mode power-supply (SMPS) controller generates logic-supply voltages in battery-powered systems. The ISL6237 includes two pulse-width modulation (PWM) controllers, 5V/3.3V and 1.5V/1.05V. The output of SMPS1 can also be adjusted from 0.7V to 5.5V. The SMPS2 output can be adjusted from 0.5V to 2.5V by setting REFIN2 voltage. This device features a linear regulator providing 3.3V/5V, or adjustable from 0.7V to 4.5V output via LDOREFIN. The linear regulator provides up to 100mA output current with automatic linear-regulator bootstrapping to the BYP input. When in switchover, the LDO output can source up to 200mA. The ISL6237 includes on-board power-up sequencing, power-good (POK_) outputs, digital soft-start, and internal soft-stop output discharge that prevents negative voltages on shutdown.

Features

• Wide Input Voltage Range 5.5V to 25V

• Dual Fixed 1.05V/3.3V and 1.5V/5.0V Outputs or Adjustable 0.7V to 5.5V (SMPS1) and 0.5V to 2.5V (SMPS2), ±1.5% Accuracy

• 1.7ms Digital Soft-Start and Independent Shutdown

• Fixed 3.3V/5.0V, or Adjustable Output 0.7V to 4.5V, ±1.5% (LDO): 200mA

• 2.0V Reference Voltage

• Constant ON-TIME Control with 100ns Load-Step Response

• Selectable Switching Frequency

• rDS(ON)Current Sensing

• Programmable Current Limit with Foldback Capability

• Selectable PWM, Skip or Ultrasonic Mode

• BOOT Voltage Monitor with Automatic Refresh

• Independent POK1 and POK2 Comparators

• Soft-Start with Pre-Biased Output and Soft-Stop

• Independent ENABLE

• High Efficiency - Up to 97%

• Very High Light Load Efficiency (Skip Mode)

• 5mW Quiescent Power Dissipation

• Thermal Shutdown

• Extremely Low Components Count

• Pb-Free Plus Anneal Available (RoHS Compliant)