lnbs21 STMicroelectronics, lnbs21 Datasheet - Page 4

• Manufacturer Part Number: lnbs21
• Description: Lnb Supply And Control Ic With Step-up Converter And I2c Interface
• Manufacturer: STMicroelectronics

LNBS21
Table 4: Pin Description
4/21
SYMBOL
DSQOUT DiSEqC Output
SENSE
DSQIN
DETIN
EXTM
ADDR
GATE
GND
OUT
SDA
SCL
BYP
V
LT1
LT2
V
CC
up
Supply Input
External Switch Gate
Current Sense Input
Step-up Voltage
Output Port
Serial Data
Serial Clock
DiSEqC Input
Detector In
External Modulator
Ground
Bypass Capacitor
Loop Through Switch
Loop Through Switch
Address Setting
NAME
8V to 15V supply. A 220µF bypass capacitor to
GND with a 470nF (ceramic) in parallel is
recommended
External MOS switch Gate connection of the
step-up converter
Current Sense comparator input. Connected to
current sensing resistor
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 of the linear post regulator modulator to the
LNB. See truth table for voltage selections.
Bidirectional data from/to I
Clock from I
When the TEN bit of the System Register is LOW,
this pin will accept the DiSEqC code from the main
modulate the internally generated 22kHz carrier. Set
to GND the pin if not used.
22kHz Tone Detector Input. Must be AC coupled to
the DiSEqC bus.
Open collector output of the tone Detector to the
main controller for DiSEqC data decoding. It is
LOW when tone is detected.
External Modulation Input. Need DC decoupling to
the AC source. If not used, can be left open.
Pins to be connected to ground.
Needed for internal preregulator filtering
In standby mode the power switch between LT1 and
LT2 is closed. Max allowed current is 900mA. this
pin can be left open if loop through function is not
needed.
Same as above
Four I
Address Pin level voltage
controller. The LNBS21 will use this code to
2
C bus addresses available by setting the
2
C bus.
FUNCTION
2
C bus.
vs. PACKAGE
1, 6, 10, 11, 20
PIN NUMBER
18
17
16
19
12
13
14
15
2
9
5
8
4
3
7