AS1326_1 Datasheet, PDF (1/18 Pages) ams AG – High Current, 0.8A DC-DC Step-Up Converters

Datasheet
AS1326
High Current, 0.8A DC-DC Step-Up Converters
1 General Description
The AS1326A/AS1326B are high-efficiency, high cur-
rent, DC-DC step-up converters specifically designed for
battery-powered wireless applications. Low quiescent
supply current (65µA), high operating frequency (1MHz),
and minimal external component requirements make
these devices perfect for small hand-held applications.
Table 1. Standard Products
Model
Input Signal Activation
AS1326A
Logic-Low On
AS1326B
Logic-High On
Both devices use synchronous-rectified pulse-width
modulation (PWM) boost technology to generate 2.5 to
5.0V outputs from a wide range of inputs, such as 1 to 3
alkaline/NiCd/NiMH cells or a single lithium-ion (Li+)
cell. Automatic powersave operation significantly
improves efficiency at light-loads.
Continuous switching mode is available for applications
requiring constant-frequency operation at all load cur-
rents. PWM operation can also be synchronized to an
external clock to protect sensitive frequency bands in
communications equipment.
Analog soft-start and adjustable current limit permit opti-
mization of rush in current and external component size.
The AS1326A/AS1326B are available in a 10-pin TDFN
(3.0mm x 3.0mm) package.
2 Key Features
! Up to 800mA Output
! Constant-Frequency (1MHz) Operation
! Up to 96% Efficiency
! Input Range: 0.7 to 5.0V
! Fixed Output: 3.3V
! Adjustable Output: 2.5 to 5.0V
! PWM Synchronous-Rectified Technology
! Logic-Controlled Shutdown: 0.1µA
! Synchronizable Switching Frequency
(0.5 to 1.2MHz)
! Adjustable Current Limit
! Adjustable Soft-Start
! 10-pin TDFN (3.0mm x 3.0mm) Package
3 Applications
The devices are ideal for digital cordless phones. mobile
phones, wireless handsets, hand-held instruments,
PDAs, two-way pagers, and any battery-operated equip-
ment.
Figure 1. AS1326 - Block Diagram
5
+
OUT _{IC Power}
Undervoltage
Lockout
2.15V –
AS1326B
only
AS1326A
only
10
ON
10
ONN
2
REF
3
On Rdy
1.25V
Reference
Ref GND
GND
6
CLK/SEL
4
FB
1
ISET
AS1326
On
Q
Startup
Osc
D
Controller
En
Osc
1MHz Osc
CLK/SEL Mode
En
Osc
Mode
FB ISET
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Revision 1.05
9
POUT
8
LX
7
PGND
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