RP502x Series

Step-down DC/DC Converter with Synchronous Rectifier

Data Sheet / Flyer
Data Sheet * Flyer

The RP502x Series are CMOS-based step-down DC/DC converters with synchronous rectifier.

Each of these ICs consists of an oscillator, a reference voltage unit, an error amplifier, a switching control circuit, a soft-start circuit, protection circuits, an UVLO circuit, and switching transistors. By adopting the synchronous rectification with built-in switching transistors, high efficient step-down DC/DC converter can be composed of only an inductor and capacitors.

As protection circuits, the current limit circuit and the latch protection circuit are built into the ICs. The current limit circuit controls the peak current of LX at each clock cycle. Latch protection circuit maintains the built-in driver in OFF state if the load current exceeds the limit value for a certain period of time. To cancel the latch protection, disable the ICs with a chip enable circuit and then enable it again or make the power supply voltage lower than UVLO.

The setting voltage for the RP502x Series is the output voltage fixed type with built-in feedback resistance that is adjustable in 0.1V step with the accuracy of ± 1.5% or ±24mV. The packages for the ICs are WLCSP-6-P2 and DFN1616-6, which enable the high-density mounting. The switching mode for the ICs is selectable from the PWM/VFM auto switching type, which achieves the high efficiency at the light load condition or PWM fixed type, which switches at the fixed frequency.

Supply Current Typ. 750μA (at normal)
Typ. 180μA (at light road)
Input Voltage Range 2.5V to 5.5V(VOUT>=1.0V)
2.5V to 4.5V(VOUT<1.0V) 
Absolute Maximum Ratings 6.0V
Output Voltage Range 0.8V to 3.3V (0.1V steps) 
Output Voltage Accuracy ±1.5% (VOUT>=1.6V)
±24mV (VOUT<1.6V) 
Oscillator Frequency Typ. 3.3MHz 
Maximum Duty Min. 100% 
Built-in Driver ON Resistance Typ. Pch. 0.5Ω, Nch. 0.5Ω(VIN=3.6V) 
UVLO Detector Threshold Typ. 2.2V 
Soft Start Time Typ. 0.12ms 
Lx Current Limit Typ. 900mA(VOUT>=1.2V)
Typ. 800mA(VOUT<1.2V) 
Latch type Protection Circuit Typ. 1.5ms 
Chip Enable Function "H" Active
Packages WLCSP-6-P2, DFN1616-6
  • Power source for battery-powered equipments.
  • Power source for hand-held communication equipments, cameras, VCRs, camcorders.
  • Power source for HDDs, portable equipments.

Data Sheet Flyer Design Guide
RP502x Series (1.19MB) RP502x Series RP502xxxxB Series
Package Info. Mark Info. Quality Assurance Data
WLCSP-6-P2 RP502Z Reliability
DFN1616-6 RP502L Reliability

All PDF files are less than 1MB unless otherwise stated.

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