AN3352 Datasheet, PDF (1/26 Pages) STMicroelectronics – Dual LNB power supply based on the LNBH24L

AN3352
Application note
Dual LNB power supply based on the LNBH24L
supply and control IC with step-up and I²C interface
Introduction
This application note is intended to provide additional information and suggestions for the
correct use of the LNBH24L device. All waveforms shown are based on the demonstration
board order code STEVAL-CBL008V1 described in Section 3.
The LNBH24L is an integrated solution for supplying/interfacing two independent LNB
down-converters in antenna dishes and/or multi-switch box. It gives good performance in a
simple and cheap way, with minimum external components necessary. It includes all
functions needed for LNB supplying and interfacing, in accordance with international
standards. Moreover, it includes an I²C bus interface and, thanks to a fully integrated step-up
DC-DC converter, it functions with a single input voltage supply ranging from 8 V to 15 V.
Figure 1.
LNBH24L internal block diagram
TTX-A ISEL-A ADDR -A SDA SCL ADDR -B Vcc Byp Vcc-L ISEL-B TTX-B
LX -A
P-GND -A
Rsense
Vup -A
VoRX -A
VoTX -A
EXTM-A
DSQIN -A
TTX-A
PDC-A
Preregulator
+U.V.lockout
+P.ON reset
EN-A
VSEL-A
TEN-A
EN-A
VSEL-A
TTX-A
TEN-B
EN-B
VSEL-B
TTX-B
EN-B
VSEL-B
ISEL-A
VOUT-A Control
VOUT-B Control
ISEL-B
Linear Post -reg
+Protections
+Diagnostics
FB
22 kHz
Oscillator
I²C Diagnostics
Linear Post -reg
+Protections
+Diagnostics
FB
22 kHz
Oscillator
LX -B
Rsense
P-GND -B
Vup -B
TTX-B
VoRX -B
VoTX -B
EXTM-B
Pull Down
Controller
TEN-A
LNBH24L
TEN-B
Pull Down
Controller
DSQIN -B
PDC-B
A-GND
AM09362v1
November 2011
Doc ID 018526 Rev 3
1/26
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