 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LNBH24 Datasheet(PDF) 5 Page - STMicroelectronics |
|
||||||||||||||||||||||||||||||
LNBH24 Datasheet(HTML) 5 Page - STMicroelectronics |
|
|
5 / 30 page  LNBH24 Introduction 5/30 2 Introduction The LNBH24 includes two completely independent sections. Except for the VCC and I²C inputs, each circuit can be separately controlled and have independent external components. The specification that follow should be considered equally for both sections (A/B). 2.1 Application information This IC has a built-in DC-DC step-up converter which, from a single 8 V to 15 V source, generates the voltages (VUP) that allow the linear post-regulator to work at a minimum dissipated power of 0.375 W Typ. @ 500 mA load (the linear post-regulator drop voltage is internally held at VUP-VOUT=0.75 V typ.). An under voltage lockout circuit will disable the entire circuit when the supplied VCC drops below a fixed threshold (6.7 V typically). Note: In this document the VOUT is intended as the Voltage present at the linear post-regulator output (VoRX pin). 2.2 DiSEqC™ data encoding and decoding The new internal 22 kHz tone generator (patent pending) is factory trimmed in accordance with the standards, and can be selected through I²C interface TTX bit (or TTX pin) and activated by a dedicated pin (DSQIN) which allows immediate DiSEqC™ data encoding, or through TEN I²C bit in case the 22 kHz presence is requested in continuous mode. In standby condition (EN bit LOW). The TTX function must be disabled setting TTX to LOW. 2.3 DiSEqC™ 2.0 implementation The built-in 22 kHz Tone detector completes the fully bi-directional DiSEqC™ 2.0 (see Note:) interfacing. Its input pin (DETIN) must be AC coupled to the DiSEqC™ bus, and extracted PWK data are available on the DSQOUT pin. To comply with the bi-directional DiSEqC™ 2.0 bus hardware requirements an output R-L filter is needed. The LNBH24 is provided with two output pins for each section, one for the DC voltage output (VoRX) and one for the 22 kHz tone transmission (VoTX). The VoTX must be activated only during the tone transmission while the VoRX provides the 13/18 V output voltage. This allows the 22 kHz Tone to pass without any losses due to the R-L filter impedance (see Figure 4). During the 22 kHz transmission, in DiSEqC™ 2.0 applications, activated by DSQIN pin or by the TEN bit, the VoTX pin must be preventively set ON by the TTX function. This can be controlled both through the TTX pin and the I²C bit. As soon as the tone transmission is expired, the VoTX must be disabled by setting the TTX to LOW to set the device in the 22 kHz receiving mode. The 13/18 V power supply is always provided to the LNB from the VoRX pin through the R-L filter. 2.4 DiSEqC™ 1.X implementation When the LNBH24 is used in DiSEqC™ 1.x applications the R-L filter is always needed for the proper operation of the 22 kHz tone generator (patent pending. See Figure 4). Also in this case, the TTX function must be preventively enabled before to start the 22 kHz data transmission and disabled as soon as the data transmission has been expired. The tone can |
Similar Part No. - LNBH24 |
|
Similar Description - LNBH24 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
