AS1321_1 Datasheet, PDF (1/13 Pages) ams AG – 130mA Step-Up DC-DC Converter

Datasheet
AS1321
130mA Step-Up DC-DC Converter
1 General Description
The AS1321 is a high-efficiency step-up DC-DC con-
verter designed to generate a fixed output 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 reg-
ulation 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.
2 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
3 Applications
The AS1321 is ideal for low-power applications 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 +5.0V supply or as
a battery backup.
Figure 1. AS1321 - Typical Application Diagram
2
BATT
+1.5V to +5.0V
Battery
CIN
22µF
4
L1
LX
10µH
On
1
Off
SHDNN
AS1321
5
OUT
COUT
22µF
6
RESETN
+5.0V
Output
R1
100kΩ
RESETN
Output
3
GND
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