The Si9161 Optimized-Efficiency Controller for RF Power Amplifier Boost Converter is a fixed-frequency, pulse- widthmodulated 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.