LNBH25LPQR STMicroelectronics

LNBH25L LNB supply and control IC with step-up and IC interface Features Complete interface between LNB and IC bus Built-in DC-DC converter for single 12 V supply operation and high efficiency (typ. 93% 0.5 A) Selectable output current limit by external resistor Compliant with main satellite receiver output voltage specifications QFN24 (4 x 4 mm) Accurate built-in 22 kHz tone generator suits widely accepted standards 22 kHz tone waveform integrity guaranteed also at no load condition the LNB down-converter in the antenna dish or to Low-drop post regulator and high efficiency the multi-switch box. In this application field, it step-up PWM with integrated power N-MOS offers a complete solution with extremely low allowing low power losses component count and low power dissipation Overload and overtemperature internal together with a simple design and IC standard protection with IC diagnostic bits interfacing. LNB short-circuit dynamic protection +/- 4 kV ESD tolerant on output power pins Applications STB satellite receivers TV satellite receivers PC card satellite receivers Description Intended for analog and digital satellite receivers/Sat-TV and Sat-PC cards, the LNBH25L is a monolithic voltage regulator and interface IC, assembled in QFN24 (4x4) specifically designed to provide the 13/18 V power supply and the 22 kHz tone signalling to Table 1. Device summary Order code Package Packaging LNBH25LPQR QFN24 (4 x 4) Tape and reel February 2012 Doc ID 022634 Rev 2 1/28 www.st.com 28Contents LNBH25L Contents 1 Block diagram 3 2 Application information 4 2.1 DiSEqC data encoding (DSQIN pin) . 4 2.2 Data encoding by external 22 kHz tone TTL signal 4 2.3 Data encoding by external DiSEqC envelope control through the DSQIN pin 5 2.4 Output current limit selection . 5 2.5 Output voltage selection . 5 2.6 Diagnostic and protection functions 5 2.7 Surge protection and TVS diodes . 6 2.8 Power-on IC interface reset and undervoltage lockout . 6 2.9 PNG: input voltage minimum detection . 6 2.10 OLF: overcurrent and short-circuit protection and diagnostic . 7 2.11 OTF: thermal protection and diagnostic . 7 3 Pin configuration 8 4 Maximum ratings . 10 5 Typical application circuits 11 6 IC bus interface . 12 6.1 Data validity . 12 6.2 Start and stop condition 12 6.3 Byte format 12 6.4 Acknowledge 12 6.5 Transmission without acknowledge . 12 7 IC interface protocol . 14 7.1 Write mode transmission . 14 7.2 Read mode transmission . 15 7.3 Data registers 16 2/28 Doc ID 022634 Rev 2