The AS1321 is a high-efficiency step-up DC-DC converter designed to generate a fixed voltage of +5.0V.
The AS1321 achieves an efficiency of up to 96%. The minimum input voltage is 1.5V, the output voltage is fixed at 5.0V, and output current is up to 130mA (@ 2V VBATT).
In order to save power the AS1321 features a shutdown mode, where it draws less than 1µA. In shutdown mode the battery is connected directly to the output enabling the supply of real-time-clocks.
The AS1321 provides a power-on reset output that goes high-impedance when the output reaches 90% of its regulation point.
The SHDNN trip threshold of the AS1321 can be used as an input voltage detector that disables the device when the battery voltage falls to a predetermined level.
An internal synchronous rectifier is included, which is parallel with the external Schottky diode.
The AS1321 is available in a 6-pin SOT23 package.
The AS1321 is ideal for low-power applications where ultra-small size is critical as in medical diagnostic equipment, hand-held instruments, pagers, digital cameras, remote wireless transmitters, cordless phones, and PC cards.
The device is also perfect as a local 5.0V supply or as a battery backup.
AS1321 5.0V DC-DC Step up Block Diagram
