AS1329_13 Datasheet, PDF (1/20 Pages) ams AG – Low Vol tage, Micropower, DC-DC Step-Up Conver ters

AS1329
Low Voltage, Micropower, DC-DC Step-Up Converters
1 General Description
The AS1329A, AS1329B and the AS1329C are synchronous, 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
modern 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. The converters
are available as the standard products listed in Table 1.
Table 1. Standard Products
Model
Light Load Switching
AS1329A
Medium Load
Automatic Powersave Operation
AS1329B
Light Load Automatic Powersave Operation
AS1329C
Continuous Switching
The devices contain two internal MOSFET switches: one NMOS
switch and one PMOS synchronous rectifier. Anti-ringing control
circuitry reduces EMI by damping the inductor in discontinuous
mode, and the devices exhibit extremely low quiescent current (<
1µA) in shutdown.
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
2 Key Features
Low Start-Up Voltage: 0.85V
Output Range: 2.5V to 5.0V
Single-Cell Operation
Operating with coils down to 2.2µH
Delivers 160mA @ 3.3V (from Single AA Cell)
Delivers 220mA @ 5.0V (from Two AA Cells)
Delivers 570mA @ 3.3V (from Two AA Cells)
95% Efficiency
High-Speed Fixed-Frequency: 1.2MHz
Internal PMOS Synchronous Rectifier
Automatic Powersave Operation (AS1329A&B)
Continuous Switching at Light Loads (AS1329C)
Logic Controlled Shutdown (< 1µA)
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 equipment, hand-held
instruments, pagers, digital cameras, remote wireless transmitters,
MP3 players, LCD bias supplies, cordless phones, GPS receivers,
and PC cards.
L1
4.7µH
AA Battery
C1
10µF
On
Off
6
VIN
4
SHDNN
1 SW
AS1329
5
VOUT
3
FB
2 GND
R1
1.02MΩ
1%
R2
604kΩ
1%
C2
10µF
VOUT
3.3V
160mA
www.ams.com/DC-DC_Step-Up/AS1329
Revision 1.12
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