AS1329 Datasheet, PDF (1/2 Pages) ams AG – Low Voltage, Micropower, DC-DC Step-Up Converters

AS1329
Product Brief
Low Voltage, Micropower, DC-DC Step-Up Converters
1 General Description
2 Key Features
The AS1329A, AS1329B and the AS1329C are synchro-
nous, fixed frequency, very high-efficiency DC-DC boost
converters capable of supplying 3.3V at 160mA from a
single AA-supply. Compact size and minimum external
parts requirements make these devices perfect for mod-
ern portable devices.
High-speed switching frequency (1.2MHz) and internally
compensated PWM current mode design provide highly-
reliable DC-DC conversion, especially when driving
white LEDs.
! 95% Efficiency
! Single-Cell Operation
! Delivers 160mA @ 3.3V (from Single AA Cell)
! Delivers 220mA @ 5.0V (from Two AA Cells)
! Delivers 570mA @ 3.3V (from Two AA Cells)
! Low Start-Up Voltage: 0.85V
The converters are available as the standard products
listed in Table 1.
Table 1. Standard Products
Model
Light Load Switching
! High-Speed Fixed-Frequency: 1.2MHz
! Internal PMOS Synchronous Rectifier
! Automatic Powersave Operation (AS1329A&B)
AS1329A
Medium Load
Automatic Powersave Operation
AS1329B Light Load Automatic Powersave Operation
AS1329C
Continuous Switching
! Continuous Switching at Light Loads (AS1329C)
! Anti-Ringing Control Minimizes EMI
! Logic Controlled Shutdown (< 1µA)
The devices contain two internal MOSFET switches:
one NMOS switch and one PMOS synchronous rectifier.
! Output Range: 2.5 to 5.0V
! 6-pin TSOT-23 Package
Anti-ringing control circuitry reduces EMI by damping
the inductor in discontinuous mode, and the devices
exhibit extremely low quiescent current (< 1µA) in shut-
down.
In shutdown mode the battery is connected directly to
the output enabling the supply of real-time-clocks.
The AS1329 is available in a 6-pin TSOT-23 package.
3 Applications
The AS1329 is ideal for low-power applications where
ultra-small size is critical as in medical diagnostic equip-
ment, hand-held instruments, pagers, digital cameras,
remote wireless transmitters, MP3 players, LCD bias
supplies, cordless phones, GPS receivers, and PC
cards.
Figure 1. Typical Application Diagram – Single Cell to 3.3V Synchronous Boost Converter
L1
4.7µH
AA Battery
C1
10µF
1 SW
6
5
VIN
VOUT
AS1329
On
4
3
Off
SHDNN
FB
2 GND
R1
1.02MΩ
1%
R2
604kΩ
1%
C2
10µF
VOUT
3.3V
160mA
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Revision 1.01
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