LNBH23
LNBs supply and control IC with step-up and I²C interface
Datasheet
−
production data
Features
■
■
Complete interface between LNB and I²C bus
Built-in DC-DC converter for single 12 V supply
operation and high efficiency (typ. 93% @ 0.75
A), with integrated NMOS
Selectable output current limit by external
resistor
Compliant with main satellite receiver systems
specifications
New accurate built-in 22 kHz tone generator
suits widely accepted standards (patent
pending)
Fast oscillator start-up facilitates DiSEqC™
encoding
Built-in 22 kHz tone detector supports bi-
directional DiSEqC™ 2.0
Very low-drop post regulator and high
efficiency step-up PWM with integrated power
NMOS allow low power losses
Two output pins suitable to by-pass the output
R-L filter and avoid any tone distortion (R-L
filter as per DiSEqC™ 2.0 specs, see typ.
application circuits)
Overload and over-temperature internal
protections with I²C diagnostic bits
Output voltage and output current level
diagnostic feedback by I²C bits
LNB short circuit dynamic protection
±
4 kV ESD tolerant on output power pins
PowerSSO-24
(Exposed pad)
QFN32 (5 x 5 mm.)
(Exposed pad)
■
■
■
■
■
■
Description
Intended for analog and digital satellite
receivers/sat-TV, sat-PC cards, the LNBH23 is a
monolithic voltage regulator and interface IC,
assembled in PowerSSO-24 ePAD and QFN32 (5
x 5 mm.) ePAD, specifically designed to provide
the 13/18 V power supply and the 22 kHz tone
signalling to the LNB down-converter in the
antenna dish or to the multi-switch box. In this
application field, it offers a complete solution with
extremely low component count, low power
dissipation together with simple design and I²C
standard interfacing.
■
■
■
■
■
Table 1.
Device summary
Order code
LNBH23PPR
LNBH23QTR
Package
PowerSSO-24 (Exposed pad)
QFN32 (Exposed pad)
Packaging
Tape and reel
Tape and reel
February 2013
This is information on a product in full production.
Doc ID 13356 Rev 8
1/32
www.st.com
32
Contents
LNBH23
Contents
1
2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
DiSEqC™ data encoding and decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
DiSEqC™ 2.0 implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
DiSEqC™ 1.X implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Data encoding by external tone generator (EXTM) . . . . . . . . . . . . . . . . . . 5
I²C interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Output voltage selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Diagnostic and protection functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Output voltage diagnostic - VMON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
22 kHz tone diagnostic - TMON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Minimum output current diagnostic - IMON . . . . . . . . . . . . . . . . . . . . . . . . 6
Output current limit selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Over-current and short circuit protection and diagnostic . . . . . . . . . . . . . . 7
Thermal protection and diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3
4
5
6
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
I²C bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.1
6.2
6.3
6.4
6.5
Data validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Start and stop condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Byte format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Transmission without acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7
LNBH23 software description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1
7.2
Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
System register (SR, 1 byte) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Doc ID 13356 Rev 8
2/32
LNBH23
Contents
7.3
7.4
7.5
7.6
7.7
Transmitted data (I²C bus write mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Diagnostic received data (I²C read mode) . . . . . . . . . . . . . . . . . . . . . . . . 17
Power-on I²C interface reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Address pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DiSEqC™ implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8
9
10
11
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Doc ID 13356 Rev 8
3/32
Block diagram
LNBH23
1
Figure 1.
Block diagram
Block diagram
ISEL
TTX
ADDR
SDA SCL
Vcc
Byp Vcc-
L
LX
PWM
PWM
Controller
Controller
Preregulator
+U.V.lockout
+P.ON reset
EN
VSEL
VSEL
TTX
ITEST
EN
Rsense
P-GND
I²C interface
Vup
VOUT Control
TEN
VoRX
Linear Post-reg
+Modulator
+Protections
+Diagnostics
22KHz
Oscill.
I²C Diagnostics
VoTX
TTX
22KHz Tone
Amp. Diagn.
22KHz Tone
Freq. Detector
DETIN
EXTM
DSQOUT
DSQIN
VCTRL
LNBH23
A-GND
4/32
Doc ID 13356 Rev 8
LNBH23
Application information
2
Application information
This IC has a built-in DC-DC step-up converter with integrated NMOS that, from a single
source from 8 V to 15 V, generates the voltages (V
UP
) that let 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 kept at V
UP
-V
ORX
=0.75 V typ.). An under voltage lockout
circuit will disable the whole circuit when the supplied V
CC
drops below a fixed threshold (6.7
V typically).
Note:
In this document the output voltage (V
O
) is intended as the voltage present at the linear
post-regulator output (V
ORX
pin).
2.1
DiSEqC™ data encoding and decoding
The new internal 22 kHz tone generator (patent pending) is factory trimmed in accordance
to the standards, and can be selected by I²C interface TTX bit (or TTX pin) and activated by
a dedicated pin (DSQIN) that allows immediate DiSEqC™ data encoding, or through TEN
I²C bit in case the 22 kHz presence is requested in continuous mode. In stand-by condition
(EN bit LOW) The TTX function must be disabled setting TTX to LOW.
2.2
DiSEqC™ 2.0 implementation
The built-in 22 kHz tone detector completes the fully bi-directional DiSEqC™ 2.0 interfacing
(see
Note 1).
It’s input pin (DETIN) must be AC coupled to the DiSEqC™ BUS, and
extracted PWK data are available on the DSQOUT pin. To comply to the bi-directional
DiSEqC™ 2.0 bus hardware requirements an output R-L filter is needed. The LNBH23 is
provided with two output pins, one for the dc voltage output (V
oRX
) and one for the 22 kHz
tone transmission (V
oTX
). The V
oTX
must be activated only during the tone transmission
while the V
oRX
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
typ. application circuit).
During the 22 kHz transmission, in DiSEqC™ 2.0 applications, activated by DSQIN pin or by
the TEN bit, the V
oTX
pin must be preventively set ON by the TTX function. This can be
controlled both through the TTX pin and by I²C bit. As soon as the tone transmission is
expired, the V
oTX
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 V
oRX
pin through the R-L filter.
2.3
DiSEqC™ 1.X implementation
When the LNBH23 is used in DiSEqC™ 1.x applications the R-L filter is always needed for
the proper operation of the new 22 kHz tone generator (patent pending. See application
circuit). 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 be activated both with the DSQIN pin or the TEN I²C bit. The DSQIN internal
circuit activates the 22 kHz tone on the V
oTX
output with 0.5 cycles ±25 µs delay from the
TTL signal presence on the DSQIN pin, and it stops with 1 cycles ±25 µs delay after the TTL
signal is expired.
Doc ID 13356 Rev 8
5/32
微控制器 MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
