LNBH21

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TABLE A: PIN CONFIGURATIONS

PIN N°

SYMBOL

NAME

FUNCTION

18

Supply Input

8V to 15V IC supply. A 220µF bypass capacitor to GND with a 470nF

(ceramic) in parallel is recommended

17

GATE

External Switch Gate

External MOS switch Gate connection of the step-up converter

16

SENSE

Current Sense Input

DC/DC Current Sense comparator input. Connected to current

sensing resistor

19

Step-up Voltage

Input of the linear post-regulator. The voltage on this pin is monitored

by internal step-ut controller to keep a minimum dropout across the

linear pass transistor

Output Port during

22KHz Tone RX

RX Output to the LNB in DiSEqC 2.0 application. See truth tables for

voltage selections on page 8 and description on page 5.

12

SDA

Serial Data

13

SCL

Serial Clock

14

DSQIN

DiSEqC Input

When the TEN bit of the System Register is LOW, this pin will accept

the DiSEqC code from the main

µcontroller. The LNBH21 will use this

code to modulate the internally generated 22kHz carrier. Set to GND

this pin if not used.

9

DETIN

Tone Detector Input

22kHz Tone Detector Input. Must be AC coupled to the DiSEcQ 2.0

bus.

15

DSQOUT DiSEqC Output

Open drain output of the tone Detector to the main

µcontroller for

DiSEcQ 2.0 data decoding. It is LOW when tone is detected.

5

EXTM

External Modulator

AC source. If not used, can be left open.

1, 6, 10,

11, 20

GND

Ground

Pins Connected to Ground.

8

BYP

Bypass Capacitor

Needed for internal preregulator filtering

3

ISEL

Current Limit Select

Set high or floating for Iout<=750mA, connect to ground for

Output Port during

22KHz Tone TX

Output of the linear post-regulator/modulator to the LNB. See truth

tables for voltage selections.

7

ADDR

Address Setting

voltage. See address pin characteristics table.