AS1345 Factsheet

High Efficiency
www.ams.com/AS1345
AS1345 – 18V, High Efficiency, DC-DC Step-Up Converter
We provide innovative
analog solutions to
- 90% Efficiency
the most challenging
applications in sensor
and sensor interfaces,
- Single Lithium Cell input range
- Multiple Peak Inductor Current Selection
- Adjustable and Preset Options
- Battery disconnect in shutdown
power management,
and wireless.
General Description
The AS1345 high efficiency DC-DC step-up converter contains an internal Nchannel power switch and an internal P-channel battery isolation switch. The device
operates from a 2.9V to 5.0V supply and can boost voltages up to 18V. A hysteretic
control scheme is used to provide the highest operating efficiency over a wide
range of input and output load conditions. The internal MOSFET switches reduce
the external component count, and a high switching frequency supports the use of
tiny surface mount components. Additional power-saving attributes include a very
low quiescent current and a true shutdown mode. The AS1345 offers a variety of
factory set inductor peak currents, allowing the user to optimise the converter for
different display sizes. When a 500mA inductor current limit is selected, the AS1345
is capable of providing 18V @ 20mA output. Built-in safety features protect the IC
from fault conditions.
Applications
Features
-
-
Small and low current demand LCD panels
Polymer LEDs (OLED)
Cell phones
PDAs
Readers
Mobile terminals
3D shutter glasses
AS1345 Block Diagram
10uF
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
LX
VDD
10uF
100k
ON
POK
Input Voltage Range: 2.9V to 5.0V
Adjustable Output Voltage Range: 5.0V to 18V
Fixed Output Voltages: 12V, 15V and 17V
Output Current up to 40mA
Peak Coil Currents: 100, 200, 350 and 500 mA
High speed hysteretic operating mode
90% Efficiency
18V @ 20mA from a single Li-Ion battery input
True Shutdown
1.8V CMOS compatible
Short Circuit and Thermal Protection
Packages:
• 8-pin (2x2mm) TDFN
• 8-bumps (1.65x0.98 mm) WL-CSP with 0.4mm pitch
AS1345
EN
FB
Vout = 5.0V to 18V
47pF
GND
OFF
Device
Peak Coil Current
AS1345A
100
adjustable or fixed
R2
mA
1uF to 10uF
R3
Output
AS1345B
200
adjustable or fixed
AS1345C
350
adjustable or fixed
AS1345D
500
adjustable or fixed
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[email protected]
© 02/2013 by ams
Subject to change without notice
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ams AG
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