2.25MHz 1A Synchronous Step-Down Converter


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The RT8057A is a high efficiency Pulse-Width-Modulated (PWM) step-down DC/DC converter, capable of delivering 1A output current over a wide input voltage range from 2.7V to 5.5V. The RT8057A is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources such as cellular phones, PDAs, hand-held devices, game console and related accessories.The internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical applications. The RT8057A enters Low Dropout Mode when normal Pulse-Width Mode cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT8057A enters shut-down mode and consumes less than 1μA when the EN pin is pulled low. The switching ripple is easily smoothed-out by small package filtering elements due to a fixed operating frequency of 2.25MHz.The RT8057A is available in a small WDFN-6SL 2x2 package.


  • Portable Instruments
  • Game Console and Accessories
  • Microprocessors and DSP Core Supplies
  • Cellular Phones
  • Wireless and DSL Modems
  • PC Cards
Key Spec.
Status Active
Vin (min) (V) 2.7
Vin (max) (V) 5.5
Number of Outputs 1
Vout (min) (V) 0.6
Output Adj. Method Resistor
Iout (max) (A) 1
Current Limit (typ) (A) 1.5
Freq (typ) (kHz) 2250
Ext Sync No
Ron_HS (typ) (mOhm) 250
Ron_LS (typ) (mOhm) 200
Iq (typ) (mA) 0.081
Features 100% Duty Cycle;Current Mode Control;Enable Input;Internal Compensation;OCP;PSM;Stable with Ceramic Capacitor
Package Type TSOT-25;WDFN2x2-6S
  • 2.7V to 5.5V Wide Input Operation Range
  • 2.25MHz Fixed-Frequency PWM Operation
  • Up to 1A Output Current
  • Up to 90% Efficiency
  • 0.6V Reference Allows Low Output Voltage
  • Internal Soft-Start
  • No Schottky Diode Required
  • Internal Compensation to Reduce External Components
  • Low Dropout Operation : 100% Duty Cycle
  • RoHS Compliant and Halogen Free
TitleLast UpdateShareDownload
2.25MHz 1A Synchronous Step-Down Converter2011/03/17
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