ST LNBH23L User Manual

LNB supply and control IC with step-up and I²C interface

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 receivers output

voltage specification

■ Auxiliary modulation input (EXTM pin)

facilitates DiSEqC™ 1.X encoding

■ Accurate built-in 22 kHz tone generator suits

widely accepted standards

■ Low-drop post regulator and high efficiency

step-up PWM with integrated power NMOS
allow low power losses

■ Overload and over-temperature internal

protections with I²C diagnostic bits

■ LNB short circuit dynamic protection

■ ± 4 kV ESD tolerant on output power pins

Applications

LNBH23L

QFN32 (5 x 5 mm)

(Exposed pad)

Description

Intended for analog and digital satellite receivers,
the LNBH23L is a monolithic voltage regulator
and interface IC, assembled in QFN32 5 x 5
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.

■ STB satellite receivers

■ TV satellite receivers

■ PC card satellite receivers

Table 1. Device summary

Order code Package Packaging

LNBH23LQTR QFN32 (5 x 5 mm) Exposed pad Tape and reel

November 2010 Doc ID 15335 Rev 4 1/25

www.st.com

25

Contents LNBH23L

Contents

1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1 DiSEqC™ data encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2 DiSEqC™ 1.X implementation by EXTM pin . . . . . . . . . . . . . . . . . . . . . . . 5

2.3 DiSEqC™ 1.X implementation with VOTX and EXTM pin connection . . . . 5

2.4 PDC optional circuit for DiSEQC™ 1.X applications using VOTX

signal on to EXTM pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.5 I²C interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.6 Output voltage selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.7 Diagnostic and protection functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.8 Over-current and short circuit protection and diagnostic . . . . . . . . . . . . . . 6

2.9 Thermal protection and diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.10 Output current limit selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5 Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

6 I²C bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.1 Data validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.2 Start and stop condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.3 Byte format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.4 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.5 Transmission without acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7 LNBH23L software description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.1 Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.2 System register (SR, 1 byte) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.3 Transmitted data (I²C bus write mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.4 Diagnostic received data (I²C read mode) . . . . . . . . . . . . . . . . . . . . . . . . 17

2/25 Doc ID 15335 Rev 4

LNBH23L Contents

7.5 Power-on I²C interface reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7.6 Address pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7.7 DiSEqC™ implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Doc ID 15335 Rev 4 3/25

Block diagram LNBH23L

1 Block diagram

Figure 1. Block diagram

LX

LX

P-GND

P-GND

Vup

Vup

Vup

Vup

Vup

Vup

VoRX

VoRX

VoTX

VoTX

EXTM

EXTM

DSQIN

DSQIN

Rsense

Rsense

TTX

TTX

PWM

PWM

Controller

Controller

ISEL TTX

ISEL TTX

EN

EN

VSEL

VSEL

Linear Post-reg

Linear Post-reg

+Protections

+Protections
+Diagnostics

+Diagnostics

FB

FB

22kHz

22kHz
Oscill.

Oscill.

VSEL

VSEL

TTX

TTX

VOUT Control

VOUT Control

..

.

..

..

.

..

TEN

TEN

SDA SCL

ADDR

ADDR

SDA SCL

I²C interface

I²C interface

I²C OLF and OTF

I²C OLF and OTF

Diagnostics

Diagnostics

Pull Down

Pull Down

Controller

Controller

LNBH23L

LNBH23L

BypV

BypV

CC

CC

Preregulator

Preregulator
+U.V.lockout

+U.V.lockout

+

+

+

+

+

+
+P.ON reset

+P.ON reset

EN

EN

V

V

CC-L

CC-L

PDC

PDC

A-GND

A-GND

4/25 Doc ID 15335 Rev 4

LNBH23L Application information

2 Application information

This IC has a built-in DC-DC step-up converter that, from a single source from 8 V to 15 V,
generates the voltages (V
dissipated power of 0.55 W typ. @ 500 mA load (the linear post-regulator drop voltage is
internally kept at V

UP

whole circuit when the supplied V

Note: In this document the V

output (V

oRX

pin).

2.1 DiSEqC™ data encoding

The internal 22 kHz tone generator 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. Besides the internal 22 kHz tone
generator, the auxiliary modulation pin (EXTM) can be driven by an external 22 kHz source
and in this case TTX must be set to low.

) that let the linear post-regulator to work at a minimum

UP

- V

= 1.1 V typ.). An under voltage lockout circuit will disable the

OUT

is intended as the voltage present at the linear post-regulator

OUT

drops below a fixed threshold (6.7 V typically).

CC

2.2 DiSEqC™ 1.X implementation by EXTM pin

In order to improve design flexibility and reduce the total application cost, an analogic
modulation input pin is available (EXTM) to generate the 22 kHz tone superimposed to the
V

DC output voltage. An appropriate DC blocking capacitor must be used to couple the

oRX

modulating signal source to the EXTM pin. If the EXTM solution is used the output R-L filter
can be removed (see Figure 5) saving the external components cost. If this configuration is
used keep TTX set to low.

The pin EXTM modulates the V

V

oRX(AC)

Where V
EXTM pins while G

= V

EXTM(AC)

oRX(AC)

and V

EXTM

x G

EXTM

EXTM(AC)

is the voltage gain from EXTM to V

voltage through the series decoupling capacitor, so that:

oRX

are, respectively, the peak to peak voltage on the V

2.3 DiSEqC™ 1.X implementation with V
connection

If an external 22 kHz tone source is not available, it is possible to use the internal 22 kHz
tone generator signal available through the V
internal circuit must be preventively set ON by setting the TTX function to High. This can be
controlled both through the TTX pin or by I²C bit. By this way the V
superimposed to the V

Figure 3). After TTX is set to High the internal 22 kHz tone generator available through the

V

pin can be activated during the 22 kHz transmission either by DSQIN pin or by the TEN

oTX

DC voltage to generate the LNB output 22 kHz tone (see

oRX

bit.The DSQIN internal circuit activates the 22 kHz tone on the V
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. As soon as the tone transmission is expired, the

pin to drive the EXTM pin. The V

oTX

.

oRX

and EXTM pin

OTX

22 kHz signal will be

oTX

output with 0.5 cycles ±

oTX

oRX

oTX

and

pin

Doc ID 15335 Rev 4 5/25

Application information LNBH23L

V

internal circuits must be disabled by setting the TTX to LOW. The 13 / 18 V power

oTX

supply will be always provided to the LNB from the V

oRX

pin.

2.4 PDC optional circuit for DiSEQC™ 1.X applications using
V

In some applications, at light output current (< 50 mA) having heavy LNB output capacitive
load, the 22 kHz tone can be distorted. In this case it is possible to add the "Optional"
external components shown in the typical application circuits (see Figure 4) connected
between V
output capacitance only when the internal 22 kHz tone is activated. This optional circuit is
not needed in standard applications having I

signal on to EXTM pin

OTX

and PDC pin. This optional circuit acts as an active pull-down discharging the

oRX

> 50 mA and capacitive load up to 250 nF.

OUT

2.5 I²C interface

The main functions of the IC are controlled via I²C bus by writing 6 bits on the system
register (SR 8 bits in write mode). On the same register there are 5 bits that can be read
back (SR 8 bits in read mode) to provide the diagnostic flags of two internal monitoring
functions (OTF, OLF) and three output voltage register status (EN, VSEL, LLC) received by
the IC (see below diagnostic functions section). In read mode there are 3 Test bits (test 1 - 2

- 3) that must be disregarded from the MCU. While, in write mode, 2 test bits (test 4 - 5) must
be always set LOW.

2.6 Output voltage selection

When the IC sections are in stand-by mode (EN bit LOW), the power blocks are disabled.
When the regulator blocks are active (EN bit HIGH), the output can be logic controlled to be
13 or 18 V by means of the V

bit (voltage SELect). Additionally, the LNBH23L is provided

SEL

with the LLC I²C bit that increases the selected voltage value to compensate possible
voltage drop along the output line. The LNBH23L is also compliant to the USA LNB power
supply standards. In stand-by condition (EN bit LOW) all the I²C bits and the TTX pin must
be set LOW (if the TTX pin is not used it can be left floating or to GND but the TTX bit must
be set LOW during the stand-by condition).

2.7 Diagnostic and protection functions

The LNBH23L has two diagnostic internal functions provided via I²C bus by reading 2 bits on
the system register (SR bits in read mode). the diagnostic bits are, in normal operation (no
failure detected), set to LOW. The diagnostic bits are dedicated to the over-temperature and
over-load protections status (OTF and OLF).

2.8 Over-current and short circuit protection and diagnostic

In order to reduce the total power dissipation during an overload or a short circuit condition,
the device is provided with a dynamic short circuit protection. It is possible to set the short
circuit current protection either statically (simple current clamp) or dynamically by the PCL
bit of the I²C SR. When the PCL (pulsed current limiting) bit is set lo LOW, the over current
protection circuit works dynamically: as soon as an overload is detected, the output is shut-

6/25 Doc ID 15335 Rev 4

LNBH23L Application information

down for a time T

, typically 900 ms. Simultaneously the diagnostic OLF I²C bit of the

OFF

system register is set to "1". After this time has elapsed, the output is resumed for a time
T

= 1/10 T

ON

protection circuit will cycle again through T

= 90 ms (typ.). At the end of TON, if the overload is still detected, the

OFF

and TON. At the end of a full TON in which no

OFF

overload is detected, normal operation is resumed and the OLF diagnostic bit is reset to
LOW. Typical T

ON

+ T

time is 990ms and an internal timer determines it. This dynamic

OFF

operation can greatly reduce the power dissipation in short circuit condition, still ensuring
excellent power-on start-up in most conditions. However, there could be some cases in
which a highly capacitive load on the output may cause a difficult start-up when the dynamic
protection is chosen. This can be solved by initiating any power start-up in static mode (PCL
= 1) and, then, switching to the dynamic mode (PCL = 0) after a chosen amount of time
depending on the output capacitance. When in static mode, the diagnostic OLF bit goes to
"1" when the current clamp limit is reached and returns LOW when the overload condition is
cleared.

2.9 Thermal protection and diagnostic

The LNBH23L is also protected against overheating: when the junction temperature
exceeds 150 °C (typ.), the step-up converter and the liner regulator are shut-off, and the
diagnostic OTF SR bit is set to "1". Normal operation is resumed and the OTF bit is reset to
LOW when the junction is cooled down to 135 °C (typ.)

2.10 Output current limit selection

The linear regulator current limit threshold can be set by an external resistor connected to
ISEL pin. The resistor value defines the output current limit by the equation:

I

(A) = 10000 / R

MAX

where R

is the resistor connected between I

SEL

limit threshold shall be 0.65 A typ with R

SEL

and GND. The highest selectable current

SEL

= 15 kΩ. The above equation defines the typical

SEL

threshold value.

Note: External components are needed to comply DiSEqC™ bus hardware requirements. Full

compliance of the whole application with DiSEqC™ specifications is not implied by the bare
use of this IC. NOTICE: DiSEqC™ is a trademark of EUTELSAT.

Doc ID 15335 Rev 4 7/25

Pin configuration LNBH23L

3 Pin configuration

Figure 2. Pin connections (bottom view)

Table 2. Pin description

Pin n° Symbol Name Pin function

19 V

18 V

CC

L Supply input 8 to 15 V analog power supply.

CC–

Supply input 8 to 15 V IC DC-DC power supply.

4 LX NMOS drain Integrated N-channel power MOSFET drain.

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

27 V

UP

Step-up voltage

monitored by the internal step-up controller to keep a minimum
dropout across the linear pass transistor.

21 V

22 V

oRX

oTX

LDO output port

Output port for 22

kHz Tone TX

Output of the integrated low drop linear regulator. See truth
tables for voltage selections and description.

TX Output to the LNB. See truth tables for selection.

6 SDA Serial data Bi-directional data from/to I²C bus.

9 SCL Serial clock Clock from I²C bus.

This pin will accept the DiSEqC code from the main µController.

12 DSQIN DiSEqC input

The LNBH23L will use this code to modulate the internally
generated 22 kHz carrier. Set to ground if not used.

This pin can be used, as well as the TTX I²C bit of the system

14 TTX TTX enable

register, to control the TTX function enable before to start the
22 kHz tone transmission. Set floating or to GND if not used.

29 Reserved Reserved To be connected to GND.

To be connected to the external NPN transistor Base to reduce

11 PDC Pull down control

the 22 kHz tone distortion in case of heavy capacitive load at
light output current. If not used it can be left floating.

External Modulation Input acts on V

13 EXTM External modulation

to superimpose an external 22 kHz signal. Needs DC
decoupling to the AC source. If not used it can be left floating.

5 P-GND Power ground DC-DC converter power ground.

8/25 Doc ID 15335 Rev 4

linear regulator output

oRX

LNBH23L Pin configuration

Table 2. Pin description (continued)

Pin n° Symbol Name Pin function

Epad Epad Exposed pad

To be connected with power grounds and to the ground layer
through vias to dissipate the heat.

20 A-GND Analog ground Analog circuits ground.

Needed for internal pre-regulator filtering. The BYP pin is

15 BYP By-pass capacitor

intended only to connect an external ceramic capacitor. Any
connection of this pin to external current or voltage sources
may cause permanent damage to the device.

10 ADDR Address setting

Two I²C bus addresses available by setting the Address pin
level voltage. See address pin characteristics table.

The resistor “RSEL” connected between ISEL and GND defines

28 ISEL Current selection

the linear regulator current limit threshold by the equation:

(typ.) = 10000 / RSEL.

I

MAX

30 Reserved Reserved To be left floating. Do not connect to GND.

1, 2, 3, 7, 8,

16, 17, 23,
24, 25, 26,

N.C.

Not internally

connected

Not internally connected pins. These pins can be connected to
GND to improve thermal performances.

31, 32

Doc ID 15335 Rev 4 9/25

Maximum ratings LNBH23L

4 Maximum ratings

Table 3. Absolute maximum ratings

(1)

Symbol Parameter Value Unit

V

, VCCDC power supply input voltage pins -0.3 to 16 V

CC-L

V

I

V

V

V

V

EXTM

UP

OUT

oRX

oTX

V

OH

DC input voltage -0.3 to 24 V

Output current Internally limited mA

DC output pin voltage -0.3 to 25 V

Tone output pin voltage -0.3 to 25 V

Logic input voltage (TTX, SDA, SCL, DSQIN, ADDR pins) -0.3 to 7 V

I

Logic high output voltage (PDC pin) -0.3 to 7 V

EXTM pin voltage -0.3 to 2 V

LX LX input voltage -0.3 to 24 V

V

BYP

Internal reference pin voltage

(2)

-0.3 to 4.6 V

ISEL Current selection pin voltage -0.3 to 4.6 V

T

STG

T

Storage temperature range -50 to 150 °C

Operating junction temperature range -25 to 125 °C

J

ESD rating with human body model (HBM) for all pins unless 4, 21, 22 2 kV

ESD

ESD rating with human body model (HBM) for pins 21, 22 4

ESD rating with human body model (HBM) for pin 4 0.6

1. Absolute maximum ratings are those values beyond which damage to the device may occur. These are stress ratings only

and functional operation of the device at these conditions is not implied. Exposure to absolute-maximum-rated conditions
for extended periods may affect device reliability. All voltage values are with respect to network ground terminal.

2. The BYP pin is intended only to connect an external ceramic capacitor. Any connection of this pin to external current or

voltage sources may cause permanent damage to the device.

Table 4. Thermal data

Symbol Parameter Value Unit

R

thJC

R

thJA

Thermal resistance junction-case 2 °C/W

Thermal resistance junction-ambient with device soldered
on 2s2p PC board

35 °C/W

10/25 Doc ID 15335 Rev 4

LNBH23L Typical application circuit

V

V

V

V

5 Typical application circuit

Figure 3. DiSEqC 1.x using internal 22 kHz tone generator

Vup

Vup

C4

12V

12V

in

in

C4
470nF

470nF C4470nF

D1

D1D1

L1

L1

C1

C1

Tone Enable control

Tone Enable control

Tone Enable control

TTL

TTL

TTL

C3

C3

C3C3

C8

C8
220nF

220nF C8220nF

I2C Bus

I2C Bus

C6

C6
470nF

470nF

LX

LX

Vcc

Vcc

Vcc-L

Vcc-L

SDA

SDA

{

{

SCL

SCL

ADDR

ADDR

DSQI N

DSQI N

D3

D3D3

LNBH23L

LNBH23L

P-GND A-GND

P-GND A-GNDP-GND A-GND

VoTX

VoTX

EXTM

EXTM

VoRX

VoRX

PDC

PDC

TTX

TTX

ISEL

ISEL

Byp

Byp

Byp

C10

C10

C10
220nF

220nF

220nF

R9

R9

R9

1.5KOh m

1.5KOh m

1.5KOh m

C15

C15

47nF

47nF

C11

C11

C11

C11
220nF

220nF

220nF

220nF

D2

D2D2

R2 (RSEL)

R2 (RSEL)

R2 (RSEL)
15kOhm

15kOhm

15kOhm

to LNB

to LNB
500mA max

500mA max

Figure 4. DiSEqC 1.x using internal 22 kHz tone generator and "optional" PDC circuit

D3

D3D3

Vup

Vup

C4

C4
470nF

470nF C4470nF

D1

D1D1

L1

L1

in

in

12V

12V

C1

C1

Tone Enable control

Tone Enable control

Tone Enable control

TTL

TTL

TTL

C3C3

C3

C3

C8

C8
220nF

220nF C8220nF

I2C Bus

I2C Bus

C6

C6
470nF

470nF

LNBH23L

LNBH23L

LX

LX

Vcc

Vcc

Vcc-L

Vcc-L

SDA

SDA

{

{

SCL

SCL

ADDR

ADDR

DSQI N

DSQI N

P-GND A-GND

P-GND A-GNDP-GND A-GND

VoTX

VoTX

EXTM

EXTM

VoRX

VoRX

PDC

PDC

ISEL

ISEL

Byp

Byp

Byp

TTX

TTX

R9

R9

R9

1.5KOh m

1.5KOh m

1.5KOh m

C15

C15

47nF

47nF

C10

C10

C10
220nF

220nF

220nF

*R5

*R5

2.2K Ohm

2.2K Ohm

C11

C11

C11

C11
220nF

220nF

220nF

220nF

D2

D2D2

Diode

Diode
1N4148

1N4148

*C14

*C14

1nF

1nF

3.3V

3.3V

(*) OPTIONAL components.

(*) OPTIONAL components.

To be used onl y in case

To be used onl y in case
of heavy capac itive load

of heavy capac itive load

R2 (RSEL)

R2 (RSEL)

R2 (RSEL)
15kOhm

15kOhm

15kOhm

to LNB

to LNB
500mA max

500mA max

*R8

*R8
150 Ohm

150 Ohm

*TR1

*TR1

*R7

*R7
22 Ohm

22 Ohm

Doc ID 15335 Rev 4 11/25

Typical application circuit LNBH23L

V

V

V

V

Figure 5. DiSEqC 1.x using external 22 kHz tone generator source through EXTM pin

D3

D3D3

D3

D3D3

Vup

Vup

VoTX

VoTX

VoRX

VoRX

PDC

PDC

PDC

PDC

PDC

PDC

DSQIN

DSQIN

DSQIN

DSQIN

DSQIN

DSQIN

ISEL

ISEL

ISEL

ISEL

ISEL

ISEL

Byp

Byp

C10

C10

C10

C10

C10

C10

C10

C10
220nF

220nF

220nF

220nF

220nF

220nF

220nF

220nF

C11

C11

C11

C11
220nF

220nF

220nF

220nF

to LNB

to LNB

to LNB

to LNB
500mA max

500mA max

500mA max

500mA max

D2

D2D2

D2

D2D2

R2 (RSEL)

R2 (RSEL)
15kOhm

15kOhm

in

in

in

in

12V

12V

12V

12V

C4

C4

C4

C4

C4
470nF

470nFC4470nF

470nF

470nFC4470nF

470nFC4470nF

D1

D1D1

D1

D1D1

D1D1

L1

L1

L1

L1

C1

C1

C1

C1

22KHz signal source

22KHz signal source

22KHz signal source

22KHz signal source

C3

C3

C8

C8
220nF

220nF

C15

C15

C15

C15

C15

C15
220nF

220nF

220nF

220nF

220nF

220nF

C6

C6

C6

C6
470nF

470nF

2

2

I2C Bus

I

I2C Bus

I

LNBH23L

LNBH23L

LNBH23L

LNBH23L

LX

LX

Vcc

Vcc

Vcc -L

Vcc -L

SDA

SDA

{

{

{

{

SCL

SCL

ADDR

ADDR

TTX

TTX

EXTM

EXTM

P-GND A-GND

P-GND A-GND

Table 5. BOM list

Component Notes

(1)

, R8

(1)

(1)

R2, R9, R5

R7

C1 25 V electrolytic capacitor, 100 µF or higher is suitable

C3 25 V, 220 µF electrolytic capacitor, ESR in the 100 mΩ to 350 mΩ range

C4, C6, C8, C10, C11, C15,

C14

(1)

D1

D2

D3 1N4001-07 or any similar general purpose rectifier

(1)

TR1

1. These components can be added to avoid any 22 kHz tone distortion due to heavy capacitive output loads. If not needed

they can be removed leaving the PDC pin floating.

L1

1/16 W resistors. Refer to the typical application circuit for the relative values

1/2 W resistors. Refer to the typical application circuit for the relative values

25 V ceramic capacitors. Refer to the typ. appl. circuit for the relative values

STPS130A or any similar schottky diode with V

> I

I

F(AV)

OUT_MAX

BAT43, 1N5818, or any schottky diode with I
be placed as close as possible to V

x (V

UP_MAX/VIN_MIN

oRX

)

F(AV)

pin

> 25 V and I

RRM

> 0.2 A, V

F(AV)

> 25 V, VF < 0.5 V. To

RRM

BC817 or similar NPN general-purpose transistor.

22 µH inductor with I

SAT

PEAK

where I

is the boost converter peak current (see

PEAK

> I

Equation 1)

higher than:

12/25 Doc ID 15335 Rev 4

LNBH23L Typical application circuit

To calculate the boost converter peak current (I

Equation 1

) of L1, use the following formula:

PEAK

Doc ID 15335 Rev 4 13/25

I²C bus interface LNBH23L

6 I²C bus interface

Data transmission from main microprocessor to the LNBH23L and vice versa takes place
through the 2 wires I²C bus Interface, consisting of the 2 lines SDA and SCL (pull-up
resistors to positive supply voltage must be externally connected).

6.1 Data validity

As shown in Figure 6, the data on the SDA line must be stable during the high semi-period
of the clock. The HIGH and LOW state of the data line can only change when the clock
signal on the SCL line is LOW.

6.2 Start and stop condition

As shown in Figure 7 a start condition is a HIGH to LOW transition of the SDA line while
SCL is HIGH. The stop condition is a LOW to HIGH transition of the SDA line while SCL is
HIGH. A STOP condition must be sent before each START condition.

6.3 Byte format

Every byte transferred to the SDA line must contain 8 bits. Each byte must be followed by an
acknowledge bit. The MSB is transferred first.

6.4 Acknowledge

The master (microprocessor) puts a resistive HIGH level on the SDA line during the
acknowledge clock pulse (see Figure 8). The peripheral (LNBH23L) that acknowledges has
to pull-down (LOW) the SDA line during the acknowledge clock pulse, so that the SDA line is
stable LOW during this clock pulse. The peripheral which has been addressed has to
generate acknowledge after the reception of each byte, otherwise the SDA line remains at
the HIGH level during the ninth clock pulse time. In this case the master transmitter can
generate the STOP information in order to abort the transfer. The LNBH23L won't generate
acknowledge if the V

supply is below the under voltage lockout threshold (6.7 V typ.).

CC

6.5 Transmission without acknowledge

Avoiding to detect the acknowledges of the LNBH23L, the microprocessor can use a simpler
transmission: simply it waits one clock cycle without checking the slave acknowledging, and
sends the new data. This approach of course is less protected from misworking and
decreases the noise immunity.

14/25 Doc ID 15335 Rev 4

LNBH23L I²C bus interface

Figure 6. Data validity on the I²C bus

Figure 7. Timing diagram of I²C bus

Figure 8. Acknowledge on the I²C bus

Doc ID 15335 Rev 4 15/25

LNBH23L software description LNBH23L

7 LNBH23L software description

7.1 Interface protocol

The interface protocol comprises:

● A start condition (S)

● A chip address byte (the LSB bit determines read (=1)/write (=0) transmission)

● A sequence of data (1 byte + acknowledge)

● A stop condition (P)

Section address (A or B) Data

MSB LSB MSB LSB

S 0 0 0 1 0 1 X R/W ACK ACK P

ACK = Acknowledge

S = Start

P = Stop

R/W = 1/0, Read/Write bit

X = 0/1, two addresses selectable by ADDR pin (see Ta b le 1 0)

7.2 System register (SR, 1 byte)

Mode MSB LSB

Write PCL TTX TEN LLC VSEL EN TEST4 TEST5

Read TEST1 TEST2 TEST3 LLC VSEL EN OTF OLF

Write = control bits functions in write mode

Read= diagnostic bits in read mode.

All bits reset to 0 at Power-on

7.3 Transmitted data (I²C bus write mode)

When the R/W bit in the chip address is set to 0, the main microprocessor can write on the
system register (SR) of the LNBH23L via I²C bus. 6 bits are available and can be written by
the microprocessor to control the device functions as per the below truth table Ta b le 6 .

16/25 Doc ID 15335 Rev 4

LNBH23L LNBH23L software description

Table 6. Truth table

PCL TTX TEN LLC VSEL EN TEST4 TEST5 Function

000100V

001100V

010100V

011100V

00 10 0

10 10 0

= 13.4 V, V

oRX

= 18.4 V, V

oRX

= 14.4 V, VUP=15.5 V, (VUP-V

oRX

= 19.5V, VUP=20.6 V, (VUP-V

oRX

= 14.5 V, (V

UP

= 19.5 V, (V

UP

UP

UP

- V

- V

oRX

oRX

Internal 22 kHz generator disabled, EXTM
modulation enabled

Internal 22 kHz controlled by DSQIN pin (only if
TTX=1)

1 1 1 0 0 Internal 22 kHz tone output is always activated

V

output is ON, V

0100

1100

oRX

OFF

output is ON, V

V

oRX

ON

Tone generator output is

oTX

Tone generator output is

oTX

0 X 1 0 0 Pulsed (Dynamic) current limiting is selected

1 X 1 0 0 Static current limiting is selected

X X X X X 0 0 0 Power block disabled

= 1.1 V)

oRX

= 1.1 V)

oRX

=1.1 V)

=1.1 V)

X = don't care

All values are typical unless otherwise specified

Valid with TTX pin floating

7.4 Diagnostic received data (I²C read mode)

LNBH23L can provide to the MCU master a copy of the diagnostic system register
information via I²C bus in read mode. The read mode is master activated by sending the
chip address with R/W bit set to 1. At the following master generated clocks bits, LNBH23L
issues a byte on the SDA data bus line (MSB transmitted first). At the ninth clock bit the
Master can:

● Acknowledge the reception, starting in this way the transmission of another byte from

the LNBH23L

● No acknowledge, stopping the read mode communication

Three bits of the register are read back as a copy of the corresponding write output voltage
register status (LLC, VSEL, EN), two bits convey diagnostic information about the over­temperature (OTF), output over-load (OLF) and three bit are for internal usage (TEST1-2-3)
and must be disregarded by the MCU software. In normal operation the diagnostic bits are
set to zero, while, if a failure is occurring, the corresponding bit is set to one. At start-up all
the bits are reset to zero.

Doc ID 15335 Rev 4 17/25

LNBH23L software description LNBH23L

Table 7. Register

TEST1 TEST2 TEST3 LLC VSEL EN OTF OLF Function

< 135°C, normal operation

J

> 150°C, power blocks disabled

J

< I

0I

O

1I

> I

O

, normal operation

OMAX

, Overload protection triggered

OMAX

These bits status must be disregarded by the
MCU.

These bits are read

exactly the same as

last write operation

XX X

Values are typical unless otherwise specified.

x = don’t care.

0T

1T

they were left after

7.5 Power-on I²C interface reset

I²C interface built in LNBH23L is automatically reset at power-on. As long as the V
below the under voltage lockout (UVL) threshold (6.7 V), the interface does not respond to
any I²C command and the system register (SR) is initialized to all zeroes, thus keeping the
power blocks disabled. Once the V
operative and the SR can be configured by the main microprocessor. This is due to 500 mV
of hysteresis provided in the UVL threshold to avoid false retriggering of the power-on reset
circuit.

rises above 7.3 V typ. The I²C interface becomes

CC

CC

stays

7.6 Address pin

It is possible to select two I²C interface addresses by means of ADDR pin. This pin is TTL
compatible and can be set as per address pin characteristics Ta bl e 1 0.

7.7 DiSEqC™ implementation

LNBH23L helps system designer to implement DiSEqC 1.x protocol by allowing an easy
PWK modulation of the 22 kHz carrier through the EXTM and V
the system to the specification is thus not implied by the bare use of the LNBH23L (see

Figure 3, Figure 4 and Figure 5).

pins. Full compliance of

oTX

18/25 Doc ID 15335 Rev 4

LNBH23L Electrical characteristics

8 Electrical characteristics

Refer to the typical application circuits, TJ from 0 to 85 °C, EN=1,
VSEL=LLC=TEN=PCL=TEST4=TEST5=TTX=0, R
I

= 50 mA, unless otherwise stated. Typical values are referred to TJ = 25 °C. V

OUT

V

pin voltage. See software description section for I²C access to the system register.

oRX

Table 8. Electrical characteristics

Symbol Parameter Test conditions Min. Typ. Max. Unit

=15 kΩ, DSQIN=LOW, V

SEL

=12 V,

IN

OUT

=

V

V

V

V

I

T

T

V

IN

I

IN

OUT

OUT

OUT

OUT

MAX

I

SC

OFF

ON

Supply voltage I

Supply current

=500mA, VSEL=LLC=1 8 12 15 V

OUT

I

=0 7 15

OUT

EN=TEN=TTX=1, I
PDC circuit not connected

OUT

=0,

20 40

mA

EN=0 2

Output voltage

VSEL=1

=500mA

I

OUT

LLC=0 17.8 18.4 19.2

LLC=1 19.5

V

Output voltage

VSEL=0
I

=500mA

OUT

LLC=0 12.8 13.4 14

LLC=1 14.4

VSEL=0 5 40

Line regulation VIN=8 to 15V

mVVSEL=1 5 60

Load regulation VSEL=0 or 1 I

Output current limiting
thresholds

RSEL=15 kΩ 500 800

RSEL= 22 kΩ 300 600

from 50 to 500mA 200

OUT

mA

Output short circuit current VSEL=0/1, AUX=0/1 1000 mA

Dynamic overload protection
OFF time

Dynamic overload protection
ON time

PCL=0, output shorted 900 ms

PCL=0, output shorted T

OFF

/10

F

TONE

Tone frequency

DSQIN=HIGH or TEN=1, TTX=1
(Using internal tone generator)

18 22 26 kHz

DSQIN=HIGH or TEN=1, TTX=1,
DiSEqC 1.X configuration using

A

TONE

D

TONE

t

r

V

PDC_OL

I

PDC_OZ

G

EXTM

Tone amplitude

Tone duty cycle

, t

Tone rise or fall time

f

PDC pin logic LOW I

PDC pin leakage current V

External modulation gain

internal generator, I
500mA, C

from 0 to 750nF, PDC

OUT

Optional circuit connected to V

from 0 to

OUT

oRX

rail

DSQIN=HIGH or TEN=1, TTX=1
(Using internal tone generator)

DSQIN=HIGH or TEN=1, TTX=1
(Using internal tone generator)

=2mA 0.3 V

PDC

=5V 1 µA

PDC

ΔV

OUT

/ ΔV

, freq. from 10 kHz to

EXTM

50 kHz

0.4 0.650 0.9 V

PP

40 50 60 %

5815µs

1.8

Doc ID 15335 Rev 4 19/25

Electrical characteristics LNBH23L

Table 8. Electrical characteristics (continued)

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

Z

Eff

T

ΔT

EXTM

EXTM

DC-DC

F

SW

V

IL

V

IH

I

IH

I

OBK

SHDN

SHDN

External modulation input
voltage

EXTM AC coupling

External modulation
impedance

DC-DC converter efficiency I

=500mA 93 %

OUT

DC-DC converter switching
frequency

DSQIN,TTX, pin logic low 0.8 V

DSQIN,TTX, pin logic high 2 V

DSQIN,TTX, pin input current VIH=5V 15 µA

Output backward current EN=0, V

OBK

Thermal shut-down threshold 150 °C

Thermal shut-down
hysteresis

(1)

400 mV

2.0 kΩ

220 kHz

=21V -6 -15 mA

15 °C

1. External signal maximum voltage for which the EXTM function is guaranteed.

Table 9. I²C electrical characteristics

(1)

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

LOW level input voltage SDA, SCL 0.8 V

IL

HIGH level input voltage SDA, SCL 2 V

V

IH

I

Input current SDA, SCL, VI = 0.4 to 4.5V -10 10 µA

I

V

f

1. TJ from 0 to 85 °C, VI = 12 V.

Low level output voltage SDA (open drain), IOL = 6mA 0.6 V

OL

Maximum clock frequency SCL 400 kHz

MAX

PP

Table 10. Address pins characteristics

(1)

Symbol Parameter Test condition Min. Typ. Max. Unit

V

ADDR-1

V

ADDR-2

V

ADDR-3

"0001010(R/W)" Address pin
voltage range

"0001011(RW)" Address pin
voltage range

"0001000(RW)" Address pin

(2)

voltage range

1. TJ from 0 to 85 °C, VI = 12 V

2. This I²C address is reserved only for internal usage. Do not use this address with other I²C peripherals to avoid address

conflicts.

R/W bit determines the transmission
mode: read (R/W=1) write (R/W=0)

R/W bit determines the transmission
mode: read (R/W=1) write (R/W=0)

R/W bit determines the transmission
mode: read (R/W=1) write (R/W=0)

00.8V

25V

05V

20/25 Doc ID 15335 Rev 4

LNBH23L Package mechanical data

9 Package mechanical data

In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK

®

packages, depending on their level of environmental compliance. ECOPACK®

®

is an ST trademark.

Doc ID 15335 Rev 4 21/25

Package mechanical data LNBH23L

Table 11. QFN32 (5 x 5 mm) mechanical data

Dim.

Min. Typ. Max.

A 0.80 0.90 1.00

A1 0 0.02 0.05

A3 0.20

b 0.18 0.25 0.30

D 4.85 5.00 5.15

D2 3.20 3.70

E 4.85 5.00 5.15

E2 3.20 3.70

e0.50

L 0.30 0.40 0.50

ddd 0.08

Figure 9. QFN32 package dimensions

(mm.)

22/25 Doc ID 15335 Rev 4

7376875/E

LNBH23L Package mechanical data

Tape & reel QFNxx/DFNxx (5x5 mm.) mechanical data

mm. inch.

Dim.

Min. Typ. Max. Min. Typ. Max.

A 330 12.992

C 12.8 13.2 0.504 0.519

D 20.2 0.795

N 99 101 3.898 3.976

T 14.4 0.567

Ao 5.25 0.207

Bo 5.25 0.207

Ko 1.1 0.043

Po 4 0.157

P 8 0.315

Doc ID 15335 Rev 4 23/25

Revision history LNBH23L

10 Revision history

Table 12. Document revision history

Date Revision Changes

27-Jan-2009 1 Initial release.

18-May-2009 2

09-Sep-2009 3 Modified: I

29-Nov-2010 4 Modified Table 10 on page 20.

Modified: Figure 3 on page 11, Figure 4 on page 11 and Figure 5 on page 12.
Added: Z

Table 8 on page 19.

EXTM

, A

IN

condition Table 8 on page 19 and Figure 5 on page 12.

TONE

24/25 Doc ID 15335 Rev 4

LNBH23L

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Doc ID 15335 Rev 4 25/25