ST LNBH24L handbook
Datasheet
LNBH24L is a monolithic voltage regulator and interface IC from ST company, it is designed for analog and digital DUAL satellite receivers/Sat-TV, Sat-PC cards, specially designed to provide the 13 / 18 V power supply and the 22 kHz tone signaling for two independent LNB down-converters in the antenna dishes and/or multi-switch box.