A S1 3 4 1
6 50 m A , U lt r a lo w Ri p p le S te p Do w n D C/ DC Co n v e r te r
1 General Description
The AS1341 is a high-efficiency step-down converter with adjustable
output voltages from 1.25V to V
IN
using supply voltages of up to
20V.
An integrated current-limited 0.4Ω MOSFET delivers load currents
up to 600mA.
The AS1341 also includes a 100% duty cycle LDO mode with a low
dropout of only 250mV for high efficiency if input voltages is in the
range of the output voltage.
The AS1341 has a low quiescent current (12µA) to improve light-
load efficiency and minimize battery use, and draws only 0.8µA in
shutdown mode.
High switching frequencies (up to 200kHz) allow the use of small
surface-mount inductors and output capacitors.
The device is available in a TDFN-8 3x3mm pin package.
2 Key Features
Output Voltages: Fixed 5V or Adjustable
Input Voltage Range: 4.5V to 20V
Output Current: Up to 600mA
1.25V Lowest Output Voltage
Efficiency: up to 96%
Quiescent Supply Current: 12µA
Power-OK Output
Internal 0.4Ω P-Channel MOSFET
Shutdown Current: 0.8µA
100% Maximum Duty Cycle for Low Dropout
Current-Limited Architecture
Thermal Shutdown
TDFN-8 3x3mm Package
3 Applications
Figure 1. AS1341 - Typical Application
The device is ideal for notebook computers, distributed power
systems, keep-alive supplies, and any other battery-operated,
portable device.
V
IN
4.5V to 20V
5
IN
4
LX
D1
L1
V
OUT
= 5V
C
IN
7
SHDNN
6
ILIMIT
8
C
OUT
+
AS1341
OUT
R
PULL
3
POK
1
FB
Indicates High-Power Trace
2
GND
www.ams.com/DC-DC_Step-Up/AS1341
Revision 1.09
1 - 18
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
