LNBH21 STMicroelectronics, LNBH21 Datasheet - Page 3

• Manufacturer Part Number: LNBH21
• Description: LNB SUPPLY AND CONTROL IC WITH STEP-UP CONVERTER ANC I2C INTERFACE
• Manufacturer: STMicroelectronics

Specifications of LNBH21

• Semi-lowdrop Post Regulator And High Efficiency Step-up Pwm For Low Power Loss: Typ. 0.56W @ 125mA

TABLE A: PIN CONFIGURATIONS
1, 6, 10,
PIN N°
11, 20
18
17
16
19
12
13
14
15
2
9
5
8
3
4
7
SYMBOL
DSQOUT DiSEqC Output
SENSE
DSQIN
DETIN
EXTM
ADDR
GATE
V
V
GND
SDA
ISEL
SCL
BYP
V
V
O
O
CC
UP
RX
TX
Supply Input
External Switch Gate
Current Sense Input
Step-up Voltage
Output Port during
22KHz Tone RX
Serial Data
Serial Clock
DiSEqC Input
Tone Detector Input
External Modulator
Ground
Bypass Capacitor
Current Limit Select
Output Port during
22KHz Tone TX
Address Setting
NAME
8V to 15V IC 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
DC/DC 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
RX Output to the LNB in DiSEqC 2.0 application. See truth tables for
voltage selections on page 8 and description on page 5.
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 controller. The LNBH21 will use this
code to modulate the internally generated 22kHz carrier. Set to GND
this pin if not used.
22kHz Tone Detector Input. Must be AC coupled to the DiSEcQ 2.0
bus.
Open drain output of the tone Detector to the main controller for
DiSEcQ 2.0 data decoding. It is LOW when tone is detected.
External Modulation Input acts on V
AC source. If not used, can be left open.
Pins Connected to Ground.
Needed for internal preregulator filtering
Set high or floating for Iout<=750mA, connect to ground for
I
Output of the linear post-regulator/modulator to the LNB. See truth
tables for voltage selections.
Four I
voltage. See address pin characteristics table.
OUT
2
C bus addresses available by setting the Address Pin level
450mA.
2
C bus.
2
C bus.
FUNCTION
O
TX. Needs DC decoupling to the
LNBH21
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