AS1340
5 0 V, M i c r o p o w e r, D C - D C B o o s t C o n v e r t e r
Product Brief
1 General Description
The AS1340 boost converter contains a 1.4A internal
switch in a tiny TDFN-8 3x3mm package. The device
operates from a 2.7 to 5.5V supply, and can boost volt-
ages up to 50V output.
The output voltage can easily be adjusted by an external
resistor divider.
The AS1340 uses a unique control scheme providing
the highest efficiency over a wide range of load condi-
tions. An internal 1.4A MOSFET reduces external com-
ponent count, and a fixed high switching frequency
(1MHz) allows for tiny surface-mount components.
The AS1340 also features power-OK circuitry which
monitors the output voltage.
Additionally the AS1340 features a low quiescent supply
current and a shutdown mode to save power. During
shutdown an output disconnect switch separates the
input from the output.
The AS1340 is ideal for LCD or OLED panels with low
current requirements and can also be used in a wide
range of other applications.
The device is available in a low-profile TDFN-8 3x3mm
package.
2 Key Features
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2.7V to 50V Adjustable Output Voltage
2.7V to 50V Input Voltage Range
2.7V to 5.5V Supply Voltage Range
High Output Currents:
- 100mA @ 12V from 3.3V V
IN
- 50mA @ 24V from 3.3V V
IN
- 30mA @ 36V from 3.3V V
IN
Efficiency: Up to 90%
Switching Frequency: 1MHz
Output Disconnect
Power-OK Output
Operating Supply Current: 30µA
Shutdown Current: 0.1µA
TDFN-8 3x3mm Package
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3 Applications
The device is ideal for OLED display power supply, LCD
bias generators, mobile/cordless phones, palmtop com-
puters, PDAs and organizers, handy terminals or any
other portable, battery-powered device.
Figure 1. Typical Application Diagram
L
1
4.7µH
V
IN
= 2.7V
to 5.5V
V
OUT
= >V
IN
to 50V
5
LX
R
1
8
FB
R
2
On
Off
1
SHDNN
7, 9
GND
V
IN
= 2.7V
to 5.5V
VCC
C
OUT
VCC
3
L
1
6
LX
3
V
IN
= 2.7V
to 5.5V
C
IN
SWVIN
2
V
CC
4
POK
6
SWOUT
V
OUT
AS1340
V
IN
= 2.7V
to ~V
OUT
3
L
1
6
LX
V
OUT
If not needed the output disconnect switch can be left unconnected which will also increase the efficiency.
Additionally the supply of the chip can be split to allow higher supply voltages for the coil. In this case the output disconnect switch must not be used.
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Revision 1.01
1-2
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