LNBH29
LNB supply and control IC with step-up and I²C interface
Datasheet
-
production data
Low-drop post regulator and high efficiency
step-up PWM with integrated power N-MOS
allowing low power losses
Overload and overtemperature internal
protection with I²C diagnostic bits
LNB short-circuit dynamic protection
+/- 4 kV ESD tolerant on output power pins
QFN16 (4x4) / (3x3)
Applications
STB satellite receivers
TV satellite receivers
PC card satellite receivers
Features
Complete interface between LNB and I²C bus
Built-in DC-DC converter for single 12 V supply
operation and high efficiency (typ. 93% @
0.5 A)
Selectable output current limit by external
resistor
Compliant with main satellite receiver output
voltage specifications
Accurate built-in 22 kHz tone generator suits
widely accepted standards
EXTM pin, auxiliary 22 kHz modulation input
(LNBH29E) extends design flexibility
22 kHz tone waveform integrity guaranteed
also at no load condition
Description
Intended for analog and digital satellite
receivers/Sat-TV and Sat-PC cards, the LNBH29
series is a monolithic voltage regulator and
interface IC, assembled in QFN16 (3x3) and
QFN16 (4x4) specifically designed to provide the
13 / 18 V power supply and the 22 kHz tone
signaling 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 a simple design and I²C
standard interfacing.
Table 1. Device summary
Order codes
LNBH29PTR
LNBH29EPTR
LNBH29QTR
LNBH29EQTR
Packages
QFN16 (3x3)
QFN16 (3x3)
QFN16 (4x4)
QFN16 (4x4)
Packaging
Tape and reel
Tape and reel
Tape and reel
Tape and reel
March 2013
This is information on a product in full production.
DocID023065 Rev 3
1/31
www.st.com
31
Contents
LNBH29
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
2.14
DiSEqC™ data encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
LNBH29: data encoding by external DiSEqC envelope control
through the DSQIN pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
LNBH29E: DISEQC data encoding by external 22 kHz signal
connected to the EXTM pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Output current limit selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Output voltage selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Diagnostic and protection functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Surge protection and TVS diodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
VMON: output voltage diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PDO: overcurrent detection on output pull-down stage . . . . . . . . . . . . . . . 6
Power-on I²C interface reset and undervoltage lockout . . . . . . . . . . . . . . . 6
PNG: input voltage minimum detection . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
COMP: boost capacitors and inductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
OLF: overcurrent and short-circuit protection and diagnostic . . . . . . . . . . . 7
OTF: thermal protection and diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3
4
5
6
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Typical application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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
2/31
DocID023065 Rev 3
LNBH29
Contents
7
I²C interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.1
7.2
7.3
7.4
Write mode transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Read mode transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DATA register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
STATUS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8
9
10
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
DocID023065 Rev 3
3/31
Block diagram
LNBH29
1
Block diagram
Figure 1. Block diagram
ADDR SCL SDA
LX
PWM CTRL
I²C Digital core
DSQIN
(1)
DAC
Drop control
Tone ctrl
Diagnostics
Protections
Isense
PGND
VUP
ISEL
Linear
Regulator
Voltage
reference
R3
R2
Gate ctrl
Current
Limit
selection
VOUT
R1
GND
BYP VCC
EXTM
(2)
AM11889v1
1. DSQIN pin available only on the LNBH29.
2. EXTM pin available only on the LNBH29E.
4/31
DocID023065 Rev 3
LNBH29
Application information
2
Application information
This IC has a built-in DC-DC step-up converter that, from a single source from 9 V to 17.5 V,
generates the voltages (V
UP
) that allow the linear post-regulator to work with a minimum
dissipated power of 0.5 W typ. @ 500 mA load (the linear post-regulator drop voltage is
internally kept at V
UP
- V
OUT
= 1 V typ.). The IC is also provided with an undervoltage
lockout circuit that disables the whole circuit when the supplied V
CC
drops below a fixed
threshold (4.7 V typically). The step-up converter is provided with a soft-start function which
reduces the inrush current during startup. The SS time is internally fixed at 4 ms typ. to
switch from 0 to 13 V and 6 ms typ. to switch from 0 to 18 V.
2.1
DiSEqC™ data encoding
The LNBH29 series includes two versions with different DiSEqC control pin solutions:
LNBH29 with DSQIN pin and LNBH29E with EXTM pin.
The LNBH29 is provided with the DSQIN logic input pin (TTL compatible) to be controlled by
an external DiSEqC data envelope source which activates the internal 22 kHz tone
generator factory trimmed. This guarantees the tone output waveform in accordance with
the DiSEqC standards.
The LNBH29E is provided with the EXTM analogic modulation input pin to be connected to
an external 22 kHz DiSEqC tone source. The tone output waveform depends on the
characteristics of an external signal injected by means of the EXTM pin.
2.2
LNBH29: data encoding by external DiSEqC envelope control
through the DSQIN pin
If an external DiSEqC code envelope source is available, it is possible to use the internal 22
kHz generator activated during the tone transmission by connecting the DiSEqC envelope
source to the DSQIN pin (see
Section 5: Typical application circuits).
In this way, the internal
22 kHz signal is superimposed to the V
OUT
DC voltage to generate the LNB output 22 kHz
tone. During the period in which the DSQIN is kept HIGH, the internal control circuit
activates the 22 kHz tone output.
The 22 kHz tone on the V
OUT
pin is activated with about 6 µs delay from the DSQIN TTL
signal rising edge, and it stops with a delay time in the range of 15 µs to 60 µs after the 22
kHz TTL signal on DSQIN has expired (refer to
Figure 2).
Figure 2. Tone enable and disable timing (using envelope signal)
DSQIN
~ 6 µs
Tone
Output
AM10427v1
15 µs ~ 60 µs
DocID023065 Rev 3
5/31
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
