SLVAF43 May 2021 TPS65235 , TPS65235-1 , TPS652353
In a DiSEqC 2.x system, switching between receiver or controller mode and accessory or peripheral mode can lead to a voltage drop or negative spike in the VOUT signal that can interfere with correct communication. Adding a Schottky diode in parallel with the LCR filter and bypassing FET reduces this voltage spike. Adding a capacitor in series with the bypass FET eliminates the voltage spike. Both solutions avoid unnecessary attenuation of the transmitted tone in receiver mode. Theoretical analysis of the equivalent circuit corroborates the practical results.