AS1312
Ultra Low Quiescent Current, Hysteretic DC-DC Step- Up Converter
1 General Description
The AS1312 is an ultra low IQ hysteretic step-up DC-DC converter.
2 Key Features
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Input voltage range: 0.7V to 5.0V
Fixed output voltage range: 2.5V to 5.0V
Peak output current: 200mA
The AS1312 achieves an efficiency of up to 94% and is designed to
operate from a +0.7V to +5.0V supply, the output voltage is fixed in
50mV steps from +2.5V to 5.0V.
Quiescent current: 1µA
In order to save power the AS1312 features a shutdown mode,
where it draws less than 100nA. In shutdown mode the battery is not
connected to the output.
Shutdown current: < 100nA
Up to 94% efficiency
If the input voltage exceeds the output voltage the device is in a
feedthrough mode and the input is directly connected to the output
voltage.
Output disconnect in shutdown
Feedthrough mode when VIN > VOUT
Adjustable low battery detection or Power-OK output selectable
No external diode or transistor required
Over temperature protection
In light load operation, the device enters a sleep mode when most of
the internal operating blocks are turned off in order to save power.
This mode is active approximately 50µs after a current pulse
provided that the output is in regulation.
Packages:
The AS1312 also offers an adjustable low battery detection. If the
battery voltage decreases below a threshold defined by two external
resistors on pin LBI, the LBO output is pulled to logic low. LBO is
working as Power-OK when LBI is connected to GND.
- 8-pin (2x2) TDFN
- 8-pin WL-CSP with 0.4mm pitch
The AS1312 is available in a 8-pin (2x2) TDFN and a 0.4mm pitch 8-
pin WL-CSP package.
3 Applications
The AS1312 is an ideal solution for handheld devices and battery
powered products.
Figure 1. AS1312 - Typical Application Diagram
L1 = 6.8µH
LX
V
IN
0.7V to 5.0V
Low Battery Detect
VIN
LBI
LBO
R
3
R
1
C1 = 22µF
V
OUT
2.5V to 5.0V
AS1312
VOUT
REF
R
2
C2 = 10µF
On
Off
EN
C
REF = 100nF
GND
www.ams.com/DC-DC_Step-Up
Revision 1.12
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