AS1321 Step-Up Converter IC

Description

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.

Key Features

• Fixed Output Voltage: 5.0V
• Output Current: Up to 130mA (@ 2V VBATT)
• Internal Synchronous Rectifier
• Shutdown Mode Supply Current: Less Than 1µA
• Efficiency: Up to 96%
• Minimum Input Voltage: +1.5V
• Accurate Shutdown Low-Battery Cutoff Threshold
• Battery Input Connected to Pin OUT in Shutdown Mode for Backup Power
• 6-pin SOT23 Package

Applications

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.

Block Diagram