SI9161 Datasheet, PDF (1/12 Pages) Vishay Siliconix – Optimized-Efficiency Controller for RF Power Amplifier Boost Converter

Si9161
Vishay Siliconix
Si9161
Optimized-Efficiency Controller for RF Power
Amplifier Boost Converter
FEATURES
• Si9160 architecture optimized for “light-load” efficiency
• High Frequency Switching (up to 2 MHz)
• Optimized Output Drive Current (300 mA)
• Standby Mode
• Wide Bandwidth Feedback Amplifier
• Single-Cell LiIon and Three-cell NiCd or NiMH Operation
DESCRIPTION
The Si9161 Optimized-Efficiency 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 Si9161 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. It
has a light-load pin which enables circuitry optimizing
efficiency at loads typical of receive operation. 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 Si9161
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 µA. 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.
APPLICATION CIRCUIT
FaxBack 408-970-5600, request 70747
www.siliconix.com
S-60752—Rev. B, 05-Apr-99
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