The RT8237C/D PWM controller provides high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, I/O, and chipset RAM supplies in notebook computers. The constant on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns "instant-on" response to load transients while maintaining a relatively constant switching frequency. The RT8237C/D achieves high efficiency at a reduced cost by eliminating the current sense resistor found in traditional current mode PWMs. Efficiency is further enhanced by its ability to drive very large synchronous rectifier MOSFETs and enter diode emulation mode at light load condition. The buck conversion allows this device to directly step down high voltage batteries at the highest possible efficiency. The pre-set frequency selections minimize design effort required for new designs. The RT8237C/D is intended for CPU core, chipset, DRAM, or other low voltage supplies as low as 0.7V. The RT8237CZQW is available in a WDFN-10L 3x3 package, The RT8237D is available in a WQFN-12L 2x2 package.
Feature
- Wide Input Voltage Range : 4.5V to 26V
- Output Voltage Range : 0.7V to 3.3V
- Built-in 0.5% 0.7V Reference Voltage
- Quick Load-Step Response within 100ns
- 4700ppm/°C Programmable Current Limit by Low Side RDS(ON) Sensing
- 4 Selectable Frequency Setting
- Soft-Start Control
- Drives Large Synchronous-Rectifier FETs
- Integrated Boot Switch
- Built-in OVP/OCP/UVP
- Thermal Shutdown
- Power Good Indicator
- RoHS Compliant and Halogen Free
Applications
- Notebook Computers
- CPU Core Supply
- Chipset/RAM Supply as Low as 0.7V
- Generic DC/DC Power Regulator
