2.25MHz 600mA Synchronous Step-Down Converter


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The RT2657 is a high efficiency Pulse-Width-Modulated (PWM) step-down DC/DC converter, capable of delivering 600mA output current over a wide input voltage range from 2.7V to 5.5V. The RT2657 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 RT2657 enters Low Dropout Mode when normal Pulse -Width Mode cannot provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT2657 enters shut-down mode and consumes less than 5μA 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 RT2657 is available in the small WDFN-6SL 2x2 package.


  • Portable Instruments
  • Game Console and Accessories
  • Microprocessors and DSP Core Supplies
  • Cellular Phones
  • Wireless and DSL Modems
  • PC Cards
  • Automotive InfoTainMent
Key Spec.
Status Active
Vin (min) (V) 2.7
Vin (max) (V) 5.5
Number of Outputs 1
Vout (min) (V) 0.6
Vout (max) (V) 5.5
Output Adj. Method Resistor
Iout (max) (A) 0.6
Current Limit (typ) (A) 1.5
Freq (typ) (kHz) 2250
Ext Sync No
Ron_HS (typ) (mOhm) 230
Ron_LS (typ) (mOhm) 250
Iq (typ) (mA) 0.3
Features 100% Duty Cycle;Cycle-by-Cycle Current Limit;Enable Input;Force PWM;Internal Compensation;OCP;OVP;SCP;Stable with Ceramic Capacitor
Package Type WDFN2x2-6S
  • VIN Range 2.7V to 5.5V
  • VOUT Range 0.6V to 5.5V (100% Duty Ratio Operation)
  • VREF = 0.6V
  • ISD ≤ 5μA (VEN = 0V)
  • Current Mode Control, Internal Compensation
  • Fixed FSW 2.25MHz
  • Enable (VIH = 1V, VIL = 0.4V); Int. Soft-Start (0.3ms)
  • Up to 600mA Output Current
  • Up to 90% Efficiency
  • Peak ILIMIT (1.5A Typical / 0.8A Min); UVLO; UVP; VIN and VOUT OVP; and OTP (150°C)
  • No Schottky Diode Required
  • Internal Compensation to Reduce External Components
  • RoHS Compliant and Halogen Free
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2.25MHz 600mA Synchronous Step-Down Converter2013/12/04
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