AS1302-BTDT AMSCO [austriamicrosystems AG], AS1302-BTDT Datasheet - Page 11

• Manufacturer Part Number: AS1302-BTDT
• Description: 5V/30mA Adaptive Inductorless Boost Converter
• Manufacturer: AMSCO [austriamicrosystems AG]

AS1302
Datasheet - D e t a i l e d D e s c r i p t i o n
Switch Configuration
The AS1302 has nine built-in power switches in the shape of two coupled H-bridge topologies. The system features
1:2 and 2:3 operation modes as well as a 1:1 operation where the input is directly connected to the output.
In 2:3 operation mode two flying capacitors are placed in series and each capacitor is charged to the half of the input
voltage. In pumping phase the flying capacitors are placed in parallel. The bottom-plates of the parallel flying
capacitors C
capacitors is boosted to a voltage equal to V
output, the output voltage in the 2:3 mode can be up to one and a half of V
5V, the regulation loop adapts the power transistor’s on-resistance to drop some voltage.
In 1:2 operation both flying capacitors are placed in parallel to the input voltage, and therefore charged to the input
voltage. During pumping phase the input voltage is connected to the bottom of the charged flying capacitors. The
voltage at the top-plates of the parallel capacitors is now boosted to 2V
capacitors to the output, the output can be charged to twice the voltage of V
5V the regulation loop limits the charge transfer to the output.
www.austriamicrosystems.com
Figure 33. 2:3 Operating Mode
Figure 34. 1:2 Operating Mode
+2.9V to 5.15V
+2.9V to 5.15V
V
V
BATT
BATT
FLY1
and C
FLY2
Charging Phase
are connected to the input voltage so that the voltage at the top-plates of the flying
SW2
C
SW2
C
Charging Phase
FLY1
FLY1
SW4
SW4
SW1
SW1
SW3
SW3
BATT
C
C
FLY2
FLY2
+ V
V
+5V
V
OUT
+5V
OUT
Revision 1.02
BATT
+2.9V to 5.15V
/2. By connecting the top-plates of the capacitors to the
+2.9V to 5.15V
V
BATT
V
BATT
BATT
BATT
. By connecting the top-plates of the
BATT
. If the top-plate voltage is higher than
. If the top-plate voltage is higher than
Pumping Phase
Pumping Phase
SW2
C
SW2
FLY1
C
FLY1
SW4
SW1
SW4
SW1
SW3
C
SW3
FLY2
C
FLY2
V
+5V
OUT
V
+5V
OUT
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