LNBH25PQR STMicroelectronics

LNBH25 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 receivers output voltage specification (15 programmable levels) 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 Low-drop post regulator and high efficiency step-up PWM with integrated power N-MOS Description allowing low power losses Intended for analog and digital satellite LPM function (low power mode) to reduce receivers/Sat-TV and Sat-PC cards, the LNBH25 dissipation is a monolithic voltage regulator and interface IC, Overload and overtemperature internal assembled in QFN24 4x4 specifically designed to protections with IC diagnostic bits provide the 13/18 V power supply and the 22 kHz tone signalling to the LNB down-converter in the LNB short-circuit dynamic protection antenna dish or to the multi-switch box. In this +/- 4 kV ESD tolerant on output power pins application field, it offers a complete solution with extremely low component count and low power Applications dissipation together with a simple design and IC standard interfacing. STB satellite receivers TV satellite receivers PC card satellite receivers Table 1. Device summary Order code Package Packaging LNBH25PQR QFN24 (4 x 4) Tape and reel February 2012 Doc ID 022433 Rev 4 1/34 www.st.com 34Contents LNBH25 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 LPM (low power mode) . 5 2.5 DiSEqC 2.0 implementation 6 2.6 Output current limit selection . 6 2.7 Output voltage selection . 6 2.8 Diagnostic and protection functions 6 2.9 Surge protections and TVS diodes . 7 2.10 FLT: fault flag . 7 2.11 VMON: output voltage diagnostic 7 2.12 TMON: 22 kHz tone diagnostic . 8 2.13 TDET: 22 kHz tone detection . 8 2.14 IMON: minimum output current diagnostic . 8 2.15 PDO: overcurrent detection on output pull-down stage . 8 2.16 Power-on IC interface reset and undervoltage lockout . 8 2.17 PNG: input voltage minimum detection . 8 2.18 ISW: inductor switching current limit . 9 2.19 COMP: boost capacitor ESR . 9 2.20 OLF: overcurrent and short-circuit protection and diagnostic . 9 2.21 OTF: thermal protection and diagnostic 10 3 Pin configuration . 11 4 Maximum ratings . 13 5 Typical application circuits 14 6 IC bus interface . 16 2/34 Doc ID 022433 Rev 4