The LT8709 operates over a –4.5V to –80V input voltage range and produces an output voltage from –0.1V to as high as 60V or from –1.4V to as low as –80V. The device’s synchronous operation replaces the output diode with a high efficiency P-channel MOSFET, thereby increasing efficiency, allowing for a higher output current (up to 20A), and eliminating the heat sink typically required in medium to high power applications. The rail-to-rail output current monitor and control enables the device to be configured as a current source. Fixed operating frequency is selectable from 100kHz to 750kHz and can be synchronized to an external clock. The LT8709 features an EN/FBIN pin circuit for slowly varying input signals and is also used for input voltage regulation to avoid collapsing a high impedance supply. The LT8709 is available in a 20-lead TSSOP package.