The AT7109 is a dual channel, constant frequency, synchronous step-down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.0V input voltage range and has a constant 1.5MHz switching frequency, enabling the use of tiny, low cost capacitors and inductors 1mm or less in height. Each output voltage is adjustable from 0.6V to 4.2V. Internal synchronous 0.35Ω, 1A power switches provide high efficiency without the need for external Schottky diodes.  

The current mode operation achieves fast line and load transient response. To maximize battery life, the p-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 250μA for each output. In shutdown, the device draws <1μA. 

 

AT7109 FEATURES 

•  High Efficiency: Up to 93% 

•  800mA Output Current 

•  2.5V to 5.5V Input Voltage Range 

•  1.5MHz Constant Frequency Operation 

•  No Schottky Diode Required 

•  Low Dropout Operation: 100% Duty Cycle  

•  0.6V Reference Allows Low Output Voltages 

•  Shutdown Mode Draws ≤ 1uA Supply Current 

•  Current Mode Operation for Excellent Line and Load Transient Response  

•  Thermal Fault Protection 

•  Short Circuit Protection

 

AT7109  APPLICATION 

•  Cellular Telephones 

•  Wireless and DSL Modems 

•  Digital Still Cameras 

•  Mp3 Players