AS1330 austriamicrosystems, AS1330 Datasheet - Page 8

• Manufacturer Part Number: AS1330
• Description: 4mhz, Low Voltage, Dc-dc Step-up Converter
• Manufacturer: austriamicrosystems

AS1330
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1330 can operate from a single-cell input voltage (V
rent mode PWM control for exceptional line- and load-regulation. With low R
and PMOS switches, the device maintains high-efficiency from light to heavy loads.
Modern portable devices frequently spend extended time in low-power or standby modes, switching to high power-
drain only when certain functions are enabled. The AS1330 is ideal for portable devices since it maintain high-power
conversion efficiency over a wide output power range, thus increasing battery life in these types of devices.
In addition to high-efficiency at moderate and heavy loads, the AS1330 includes an automatic powersave mode that
improves efficiency of the power converter at light loads. The powersave mode is initiated if the output load current
falls below a factory programmed threshold.
Figure 19. AS1330 - Block Diagram
Low-Voltage Start-Up
The AS1330 requires V
NMOS switch up to a maximum peak inductor current of 650mA (typ), with 1.5ms (approx.) off-time during start-up,
allowing the devices to start up into an output load.
With a V
mode, the AS1330 operates independent of V
tenths of a volt without affecting output regulation. The limiting factor for the application is the ability of the battery to
supply sufficient energy to the output.
www.austriamicrosystems.com/DC-DC_Step-Up/AS1330
AA Battery
OUT
On
Off
4.7µF
C1
> 1.65V, the start-up circuitry is disabled and normal fixed-frequency PWM operation is initiated. In this
SENSE
VIN
EN
6
4
1
Powersave
IN
Start Up
of only 0.85V (typ) or higher to start up. The low-voltage start-up circuitry controls the internal
OSC
Shutdown
Control
Control
PWM
Generator
4MHz
Ramp
Powersave
Comp
PWM
Operation
Control
Shutdown
A
B
+
–
–
MUX
A/B
Compensator
IN
, allowing extended operating time as the battery can drop to several
Slope
Sense & POK
1µH
Logic
L1
R
C
Revision 1.04
C
C
Sync Drive
IN
Control
) below 1V, and features fixed frequency (4MHz) and cur-
C
Σ
P2
1
2
0.25Ω
SW
GND
Current
Sense
DS(ON)
AS1330
Good
V
g
OUT
m
Amp
Error
0.35Ω
and gate charge internal NMOS
–
+
–
+
0.8V
Ref
1.65V
5
VOUT
3
FB
4
POK
4.7µF
C2
Output
1.8V
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