AS1320
200mA Step-Up DC-DC Converter
www.austriamicrosystems.com Revision 1.03 1 - 12
Data Sheet
1 General Description
The AS1320 is a high-efficiency step-up DC-DC con-
verter designed to generate a fixed voltage of +3.3V.
The AS1320 achieves an efficiency of up to 90%. The
minimum input voltage is 1.5V, the output voltage is
fixed at 3.3V, and output current is up to 200mA (@ 2V).
In order to save power the AS1320 features a shutdown
mode, where it draws less than 1µA. In shutdown mode
the battery is connected directly to the outpu t en a bling
the supply of real-time-clocks.
The AS1320 provides a power-on reset output that goes
high-impedance when the output reaches 90% of its reg-
ulation point.
The SHDNN trip threshold of the AS1320 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, thus an
external transistor or Schottky diode is not require d.
The AS1320 is available in a 6-pin SOT23 package.
Figure 1. Application Diagram
2 Key Features
! Fixed Output Voltage: 3.3V
! Output Current: Up to 200mA (@ 2V)
! Internal Synchronous Rectifier
! Requires No External Schottky Diod e or FETs
! Shutdown Mode Supply Current: Less Than 1µA
! Efficiency: Up to 90%
! Minimum Input Volt age: +1.5V
! Accurate Shutdown Low-Bat tery Cutoff Threshold
! Battery Input Connected to Pin OUT in Shutdown
Mode for Backup Power
! 6-pin SOT23 Package
3 Applications
The AS1320 is ideal for low-power application s where
ultra-small size is critical as in medical diagnostic equip-
ment, hand-held instruments, pagers, digital cameras,
remote wireless transmitters, cordless phones, and PC
cards.
The device is also perfect as a local 3.3V supply or as a
battery backup.
AS1320
+1.5 to +3.5V
Battery
+3.3V
Output
COUT
22µF
CIN
22µF
L1
10µH
RESETN
Output
R1
100kΩ
On
Off
4
LX
3
GND
2
BATT
6
RESETN
1
SHDNN
5
OUT
