STEVAL-LNBH02 STMicroelectronics

S T E VA L - L N B H 0 2 Power supply evaluation board for LNB based on the LNBH25S Data brief Description This evaluation board implements a DC-DC converter based on the LNBH25S device. It is used to power LNBs inside dish antennas to receive satellite TV signals. The LNBH25S is an integrated solution for supplying / interfacing satellite LNB modules in accordance with international standards. It is a simple and complete solution for dual tuner satellite receivers and provides high performance at low cost with a low external component count. The LNBH25S evaluation board includes an IC bus interface and an internal 22 kHz tone generator which is factory trimmed and can be controlled by the DSQIN pin (TTL compatible), Features allowing immediate DiSEqC data encoding. Complete interface between LNB and IC bus Thanks to a fully integrated step-up DC-DC Built-in DC-DC converter for single 12 V converter, it functions with a single input voltage supply operation and high efficiency (typ. supply source ranging from 8 V to 16 V. 93% at 0.5 A) Selectable output current limit by external resistor Compliant with main satellite receivers output voltage specification (15 programmable levels) 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 for low power losses LPM function (low power mode) to reduce dissipation Overload and overtemperature internal protection with IC diagnostic bits LNB short-circuit dynamic protection +/- 4 kV ESD tolerant on output power pins RoHS compliant September 2016 DocID029704 Rev 1 1/4 www.st.com For further information contact your local STMicroelectronics sales office Schematic diagram STEVAL-LNBH02 1 Schematic diagram Figure 1: STEVAL-LNBH02 circuit schematic D2 V V OUT UP LNBOUT D1 C5 D3 C2A C2B C3 LNBH25S LX BPSW L1 DiSEqC 22 KHz TTL Tone enable control Vin DSQIN or Vcc 12 V DiSEqC envelope TTL C4 DSQOUT C1 DL1 SDA 2 I C Bus FLT +5 V SCL R2 R1 (RSEL) ADDR ISEL Byp DETIN C6 P-GND A-GND GSPG0909161100SG 2/4 DocID029704 Rev 1