ISL9491A

DATASHEET ISL9491, ISL9491A Single Output LNB Supply Voltage Regulator for Satellite Set-Top Box Applications FN6531 Rev 1.00 August 12, 2015 These devices are designed for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise blocks (LNBs) of single antenna ports. Each device consists of a current-mode boost converter and a low-noise linear regulator along with the circuitry required for tone injection and pin controllable interface. The device makes the total LNB supply design simple, efficient and compact with low external component count. The current-mode boost converters provide the linear regulator with input voltage that is set to the voltage at the VOUT pin plus a minimal drop to insure minimum power dissipation across the internal LDO. This maintains constant voltage drop across the linear pass element while permitting adequate voltage range for tone injection. The final regulated output voltage is available at the cathode ...