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The RT8240A/B/C 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 RT8240A/B/C supports on chip voltage programming function between 1V and 1.05V by controlling G0 digital inputs.
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 RT8240A/B/C 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 RT8240A/B/C is intended for CPU core, chipset, DRAM, or other low voltage supplies as low as 1V. The RT8240A/B/C is available in a WQFN -12L 2x2 package.

Applications

  • Notebook Computers
  • CPU/GPU Core Supply
  • Chipset/RAM Supply
  • Generic DC/DC Power Regulator
Key Spec.
RT8240A RT8240B RT8240C
Status Active Active Active
Vs (typ) (V) 5 5 5
Vin (min) (V) 4.5 4.5 4.5
Vin (max) (V) 26 26 26
Vout (min) (V) 1 1 1
Vout (max) (V) 3.6 3.6 3.6
Output Adj. Method Digital;Resistor Digital;Resistor Digital;Resistor
Accuracy (+/- %) 0.5 0.5 0.5
Freq (typ) (kHz) 300 400 500
Iq (typ) (mA) 0.5 0.5 0.5
Ext Sync No No No
Features Adjustable Current Limit;Built-in Bootstrap Switch;COT Control;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;OVP;PSM;Power Good;SCP;Stable with Ceramic Capacitor;UVP Adjustable Current Limit;Built-in Bootstrap Switch;COT Control;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;OVP;PSM;Power Good;SCP;Stable with Ceramic Capacitor;UVP Adjustable Current Limit;Built-in Bootstrap Switch;COT Control;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;OVP;PSM;Power Good;SCP;Stable with Ceramic Capacitor;UVP
Package Type WQFN2x2-12 WQFN2x2-12 WQFN2x2-12
Features
  • Built-in 0.5% Reference Voltage
  • 1 Bit Programmable Output Voltage Between 1V and 1.05V with Integrated Transition Support
  • Output Voltage Range from 1V to 3.6V
  • Quick Load-Step Response within 100ns
  • Support Pure MLCC Output Capacitor
  • 4700ppm/°C Programmable Current Limit by Low Side RDS(ON) Sensing
  • 4.5V to 26V Battery Input Range
  • Internal Ramp Current Limit Soft-Start Control
  • Drives Large Synchronous Rectifier FETs
  • Integrated Boost Switch
  • Over/Under Voltage Protection
  • Thermal Shutdown
  • Power Good Indicator
  • RoHS Compliant and Halogen Free
Datasheet
TitleLast UpdateDownload
High Efficiency Single Synchronous Buck PWM Controller2017/05/16
Technical Documents
TitleItem TypeLast UpdateDownload
Richtek Product Selection Guide [Jan., 2024] Selection Guide2024/01/18
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT8240BZQWWQFN2x2-122500 Request Buy from Distributor
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