Product Brief
AS1329
Low Voltage, Micropower, DC-DC Step-Up Converters
1 General Description
2 Key Features
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95% Efficiency
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.
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
High-speed switching frequency (1.2MHz) and internally
compensated PWM current mode design provide highly-
reliable DC-DC conversion, especially when driving
white LEDs.
High-Speed Fixed-Frequency: 1.2MHz
Internal PMOS Synchronous Rectifier
Automatic Powersave Operation (AS1329A&B)
Continuous Switching at Light Loads (AS1329C)
Anti-Ringing Control Minimizes EMI
Logic Controlled Shutdown (< 1µA)
Output Range: 2.5 to 5.0V
The converters are available as the standard products
listed in Table 1.
Table 1. Standard Products
Model
Light Load Switching
Medium Load
Automatic Powersave Operation
AS1329A
AS1329B Light Load Automatic Powersave Operation
AS1329C Continuous Switching
The devices contain two internal MOSFET switches:
one NMOS switch and one PMOS synchronous rectifier.
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.
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.
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.
Figure 1. Typical Application Diagram – Single Cell to 3.3V Synchronous Boost Converter
L1
4.7µH
1
SW
VOUT
3.3V
160mA
6
5
AA Battery
VOUT
VIN
C2
10µF
C1
10µF
R1
1.02MΩ
1%
AS1329
4
3
On
Off
SHDNN
FB
R2
604kΩ
1%
2
GND
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