LNB voltage regulator offers a complete solution with simple design

Designed for analog and digital satellite receivers, the Texas Instruments TPS65235-1 is a monolithic voltage regulator with I2C interface; specifically to provide the 13V to 18V power supply and the 22kHz tone signal to the LNB down converter in the antenna dish or to the multi-switch box. It offers a complete solution with minimum component count, low power dissipation together with simple design and I2C standard interface. The device features high power efficiency. The boost converter integrates a 140mohm power MOSFET running at 1MHz or 500kHz selectable switching frequency. Drop out voltage at the linear regulator is 0.8V to minimize power loss. It provides multiple ways to generate the 22kHz signal. Integrated linear regulator with push-pull output stage generates 22kHz tone signal superimposed at the output even at zero loading. Current limit of linear regulator can be programmed by external resistor with ±10% accuracy. Full range of diagnostic read by I2C is available for system monitoring. The device has a special design at FCCM mode to avoid the audible noise especially when VIN is higher or closer to the VLNB output. It supports advanced DiSEqC 2.x standard with 22-kHz tone detection circuit and output interface.