Si9160
Vishay Siliconix
Controller for RF Power Amplifier Boost Converter
FEATURES
D
High Frequency Switching (up to 2 MHz)
D
Optimized Output Drive Current (350 mA)
D
Standby Mode
D
Wide Bandwidth Feedback Amplifier
D
Single-Cell LiIon and Three-cell NiCd or NiMH Operation
DESCRIPTION
The Si9160 Controller for RF Power Amplifier Boost Converter
is a fixed-frequency, pulse-width-modulated power conversion
controller designed for use with the Si6801 application specific
MOSFET. The Si9160 and the Si6801 are optimized for high
efficiency switched-mode power conversion at 1 MHz and
over. The device has an enable pin which can be used to put
the converter in a low-current mode compatible with the
standby mode of most cellular phones. A wide bandwidth
feedback amplifier minimizes transient response time allowing
the device to meet the instantaneous current demands of
today’s digital protocols. The input voltage range
accommodates minimal size and cost battery pack
configurations.
Frequency control in switching is important to noise
management techniques in RF communications. The Si9160
is easily synchronized for high efficiency power conversion at
frequencies in excess of 1 MHz.
Optimizing the controller and the synchronous FETs results in
the highest conversion efficiency over a wide load range at the
switching frequencies of interest (1 MHz or greater). It also
minimizes the overshoot and gate ringing associated with
drive current and gate charge mismatches.
When disabled, the converter requires less than 330
mA.
This
capability minimizes the impact of the converter on battery life
when the phone is in the standby mode.
Finally, operating voltage is optimized for LiIon battery
operation (2.7 V to 4.5 V) and can also be used with three-cell
NiCd or NiMH (3 V to 3.6 V), as well as four-cell NiCd or NiMH
(4 V to 4.8 V) battery packs.
The Si9160 is available in both standard and lead (Pb)-free
packages.
APPLICATION CIRCUIT
4.7
mH
1
20
mF
LS4148
2
3
Si9160
V
DD
0.1
mF
100 k
0.1
mF
2.2 k
10 k
N/C
D
MAX
COMP
FB
NI
V
REF
0.1
mF
GND
V
S
D
R
D
S
PGND
UVLO
SET
C
OSC
R
OSC
ENABLE
56 pF
12 k
To Power
Management
1.2 k
0.1
mF
100
W
5600 pF
3.6 k
4
D
1
S
1
S
1
G
1
D
2
8
7
6
5
LS4148
20
mF
6 V @ 500 mA
1 Cell
LiIon
Si6801
S
2
S
2
G
2
Document Number: 70029
S-40700—Rev. H, 19-Apr-04
www.vishay.com
1
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