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The RT8237L 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 RT8237L 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 to 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 the effort required for new designs. The RT8237L is intended for CPU core, chipset, DRAM, or other low voltage supplies down to 0.7V. The RT8237L is available in the VQFN-16L 3x3 package.

The recommended junction temperature range is -40°C to 125°C and ambient temperature range is -40°C to 85°C.

Applications

  • Notebook Computers
  • CPU Core Supply
  • Chipset/RAM Supply Down to 0.7V
  • Generic DC-DC Power Regulator
Key Spec.
RT8237L
Status Active
Vs (typ) (V) 5
Vin (min) (V) 4.5
Vin (max) (V) 26
Vout (min) (V) 0.7
Vout (max) (V) 3.3
Output Adj. Method Resistor
Freq (typ) (kHz) 435;510;570;645
Iq (typ) (mA) 0.5
Features Adjustable Current Limit;Adjustable Frequency;COT Control;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;OCP;Power Good;Selectable (PSM or PWM);UVP
Package Type VQFN3x3-16
Features
  • 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 Current Source for Current Limit RDS(ON)
  • Adjustable Current Limit with Low-side MOSFET
  • 4 Selectable Frequency Settings
  • Soft-Start Control
  • Drives Large Synchronous-Rectifier FETs
  • Integrated Boot Switch
  • Built-in OCP/UVP
  • Thermal Shutdown
  • Power Good Indicator
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