UM3501
UM3501 is Synchronous Step-Down DC-DC Converter manufactured by Union Semiconductor.
600m A, 1.2MHz, Synchronous Step-Down DC-DC Converter UM3501 SOT23-5
UM3501DA DFN6L 2.0×2.0
General Description
UM3501 is a high-efficiency pulse-width-modulated (PWM) step-down DC-DC converter, capable of delivering 600m A output current over a wide input voltage range from 2.5V to 5.5V. The target application of UM3501 is for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources within the range such as cellular phones, PDAs and handy-terminals. Internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application. The UM3501 automatically turns off the synchronous rectifier while the inductor current is low and enters discontinuous PWM mode. This can increase efficiency at light load condition. UM3501 enter shutdown mode and consumes less than 0.1u A when EN pin is pulled low. The operation frequency is set to 1.2MHz. This along with small SOT23-5 package and DFN6L 2.0×2.0 package provides small PCB area application. Other Features include lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection.
Applications z Cellular and Smart Phones z Microprocessors and DSP Core
Supplies z Wireless and DSL Modems z PDAs, GPS z MP3 Player z Portable Instruments
Features z High Efficiency: Up to 90% z 1.2MHz Constant Switching Frequency z 600m A Output Current z Integrated Main Switch and Synchronous
Rectifier. No Schottky Diode Required z 2.5V to 5.5V Input Voltage Range z Low Quiescent Current: 50µA z Thermal Fault Protection z <1µA Shutdown Current z Lead Free SOT23-5 Package and DFN6L
2.0×2.0 Package
Typical Application Circuit
C1 4.7u F
L1 2.2u H
R2 634K
VOUT 1.8V
C3 10u F
R1 316K
________________________________________________________________________ http://.union-ic. Rev.07 Nov.2016
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Pin Configurations
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