AS1302
5V/30mA Adaptive Inductorless Boost Converter
www.austriamicrosystems.com Revision 1.02 1 - 18
Datasheet
1 General Description
The AS1302 is a 30mA inductorless boost converter
using a double H-bridge charge-pump topology with two
external flying capacitors. The AS1302 charge pump
features 1:2 and 2:3 operation modes as well as a 1:1
operation mode where the input is directly connected to
the output.
The AS1302 runs on a 1.2MHz fixed frequency and is
utilized with a low noise regulati on scheme to allow
usage together with sensitive RF circuitry from the same
battery supply. Additionally to increase efficiency the
AS1302 switches to 49kHz at light loads.
Designed to reside in portable and space limited
equipment the 1.2MHz charge pump converts a 2.9V to
5.15V input to regulated 5V output with 3% accuracy.
The shutdown function reduces the supply current to
<1µA and disconnects the load from the output. The
integrated soft-start circuitry prevents high inrush
currents being drawn from the battery during start-up.
The AS1302 includes built-in under-voltage lockout,
short circuit-, and thermal pr ot ection circuitry.
The AS1302 is available in TDFN (3x3x0.8mm) 10-pin
and an extremely small 1.2x1.2mm WL-CSP 8-bumps
package with 0.4mm pitch.
2 Key Features
! Up to 90% Efficiency
! 2.9V to 5.15V Input Voltage
! Regulated 5V Outpu t
! Automatic Mode Switching
! <1µA Shutdown Current
! Startup with Full Load (within 1ms)
! Up to 30mA Load Current
! Short Circuit Protection
! Output Disconnected During Shutdown
! Soft-Start
! No Inductor Required
! Small External Components Required
(COUT =2.2µF, CFLY =220nF)
! Low Noise Fixed Frequ ency (1.2MHz, 49kHz)
Charge Pump:
- 1:1 Battery Feed Through Mode
- 2:3 Single Phase Mode
- 1:2 Single Phase Mode
! Package Options:
- TDFN (3x3x0.8mm) 10-pin
- WL-CSP 8-bumps with 0.4mm Pitch
3 Applications
The device is ideal for two or three AA cells or a single
Li-Ion battery cell to 5V conversion, mobile phones,
portable instruments, microprocessor based systems
and remote data-acquisition systems
.
Figure 1. AS1302 - Typical Application Diagram
VBATT
C
BAT
AS1302
2.2µF
VBATT
EN
GND
VOUT
C1+
C1-
C2+
C2-
VOUT = 5V
C
OUT
2.2µF
On
Off
C
FLY1
C
FLY2
2.9V to 5.15V
220nF
220nF
