1.2MHz, 2A, High Efficiency PWM Step-Down DC/DC Converter


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The RT8058A is a current mode PWM step-down converter. The chip is ideal for fixed frequency and low ripple applications over full range of load conditions. Its input voltage range is from 2.6V to 5.5V with a constant 1.2MHz switching frequency that allows it to adopt tiny, low cost capacitors and inductors with 2mm or less in height making it ideal for single-cell Li-lon/polymer battery applications. The low on resistance internal MOSFET can achieve high efficiency without the need of external schottky diodes in wide operating ranges and the output voltage is adjustable from 0.6V to 5V that can provide up to 2A load current. The RT8058A operates at 100% duty cycle for low dropout operation that extends battery life in portable devices.
The RT8058A is available in a WDFN-10L 3x3 package.


  • Portable Instruments
  • Microprocessors and DSP Core supplies
  • Cellular Telephones
  • Wireless and DSL Modems
  • Digital Cameras
  • PC Cards
Key Spec.
Status Active
Vin (min) (V) 2.6
Vin (max) (V) 5.5
Number of Outputs 1
Vout (min) (V) 0.6
Vout (max) (V) 5
Output Adj. Method Resistor
Iout (max) (A) 2
Current Limit (typ) (A) 3
Freq (typ) (kHz) 1200
Ext Sync No
Ron_HS (typ) (mOhm) 142
Ron_LS (typ) (mOhm) 96
Iq (typ) (mA) 0.34
Features 100% Duty Cycle;Current Mode Control;Enable Input;Force PWM;Internal Compensation;OCP;OTP;Power Good;Stable with Ceramic Capacitor;UVP
Package Type WDFN3x3-10
  • 0.6V Reference Allows Low Output Voltage
  • Low Dropout Operation : 100% Duty Cycle
  • 2A Load Current
  • < 2μA Shutdown Current
  • Up to 95% Efficiency
  • No Schottky Diode Required
  • 1.2MHz Constant Switching Frequency
  • Low RDS(ON) Internal Switches
  • Internally Compensated
  • Internal Soft-Start
  • Over temperature Protection
  • Short Circuit Protection
  • Small 10-Lead WDFN Package
  • RoHS Compliant and Halogen Free
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