Diodes ZLNB2012 User Manual

DUAL TONE AND POLARITY SWITCH
LNB MULTIPLEX CONTROLLER

DEVICE DESCRIPTION

The ZLNB2012 dual polarisation and tone switch
controller is one of a wide range of satellite receiver
LNB support circuits available from Zetex. It features
two completely independent channels, each providing
logic outputs to control LNB polarisation selection,
local oscillator selection and downfeed disable. It is
intended for use in Twin, Quad and multiple feed
Universal LNBs, replacing many discrete components
to save both manufacturing cost and PCB size whilst
improving reliability.

The two highly accurate polarisation control inputs of
the ZLNB2012 have a nominal threshold of 14.25V and
to meet the required demanding needs from some
broadcasters they have a switching range of 14.0V to

14.5V. The threshold is temperature compensated to
minimise drift. Each features a low and stable input
current that enables transient protection to be
achieved with the addition of only a single resistor per
channel.

Multi Feed LNBs can be called to operate with one or
more of their controlling receivers powered
down/disconnected, with attendant cable mismatch
problems. To ease design for this situation, each
polarisation input of the ZLNB2012 has a second
threshold set at 9V. An input voltage below this
threshold indicates“ receiver not present”, and
switches the relevant control channels high. This logic
output canbeused to disable the associateddownfeed
driver, eliminating any problems due to cable
mismatch.

ZLNB2012

Universal LNB local oscillator selection is achieved by
detection of a low level AC voltage superimposed on
the polarisation control voltage. To facilitate this
function, the ZLNB2012 includes a separate tone
detector for each channel. Control of detector
bandwidth and sensitivity is provided using an
external resistor and capacitor for each channel. The
tone detector has been designed give excellent
rejection of low frequency control signals and
DiSEqC™ tone bursts.

The ZLNB2012 has been specifically designed to
minimise the solution cost whilst being flexible. The
ZLNB2012 only requires two external components per
channel to give full user control and functionality. The
ZLNB2012 also includes complimentary outputs so
that it can directly drive many multiplexer IC’s without
the need of an inverter. Any unused outputs can be left
open circuit without any effect to the remaining circuits
operation Polarisation switch and tone detector
outputs can directly drive TTL and CMOS logic, pin
diodes, IF-amp supply switching and multiplexer IC’s.

The ZLNB2012 operates from a single supply which
can be anything from 5-8V. Its quiescent current is
typically only 9mA and this does not change
significantly with loadorlogicstate.It is availablein the
space saving QSOP16 surface mount package.

FEATURES

·

Dual polarisation and tone switch

·

Reduced Cost Solution, only 2 external components
per channel

·

Close tolerance (14-14.5V) and temperature
compensated polarisation switch

·

Multiplexer IC direct drive

·

Tone andpol.Outputs are TTL, CMOS,Pindiode and
IF amp capable

·

Transient resistant inputs

·

Includes Receiver-Off detector

·

User adjustable filter centre frequency and
bandwidth

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·

Low frequency and DiSEqC control signals
rejection

·

Eliminates many close tolerance discrete
components

·

Wide supply operating range

·

Low quiescent current

APPLICATIONS

·

Twin Universal LNB’s

·

Quad Universal LNB’s

·

Multi Feed Universal LNB’s

·

LNB switch boxes

1

ZLNB2012

ABSOLUTE MAXIMUM RATINGS

Supply Voltage -0.6V to 12V

Supply Current 500mA

V

and V

POL1

Input Voltage 25V Continous
Operating Temperature -40 to 80°C

Storage Temperature -40 to 85°C

POL2

Power Dissipation (T

amb 25 C)

QSOP16 500mW

ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):

T

amb= 25⬚C,VCC

SYMBOL PA RAMETER CONDITIONS

V

CC

I

CC

I

POL

V

TPOL

T

SPOL

VHOR

HIGH

VHOR

LOW

VBHOR

HIGH

VBHOR

LOW

VEN

HIGH

VEN

LOW

V

OUT

F

inz

AG Amplifier Gain V
FV

T

=5V

LIMITS

Min Typ Max
Supply Voltage 5 8 V
Supply Current HOR1,2= BHOR1,2= TD1,2= BTD1, 2= 0mA

1= V

2= Don’t Care

POL

= 25V (Note 2)

=-40°C to 80°C

1,2=-100␮A,V

OUT

1,2=5mA,V

OUT

2 Outputs

1,2=-100␮A,V

OUT

1,2=5mA,V

OUT

POL

POL

POL

POL

POL

1,2=14V

1,2=14.5V

1,2=14.0V

POL

1,2=14.5V

1,2=10V

1,2=8.0V

and V

V

POL1

POL2

Inputs

Current
Threshold Voltage
Switching Speed

HOR

1 and HOR

OUT

Voltage High
Voltage Low

BHOR

1 and BHOR

OUT

Voltage High
Voltage Low

Enable 1,2
Outputs

Voltage High
Voltage Low

V

POL

1= FIN2= Don’t Care

F

IN

V

POL1=VPOL2

T

amb

2 Outputs

OUT

IHOR
IHOR

OUT

IBHOR
IBHOR

IEnable 1,2=-100␮A,V
IEnable 1,2=500␮A,V

Filter Amplifier

3

I

Bias Voltage
Input Impedance V

V Threshold

3

=0 1.75 1.95 2.15 V

fin

=100mV p/p 150 ⍀

FIN

=100mV p/p 30 V/mA

FIN

10014200

V

V

V

100 170 350 mV

912mA

14.25

-1.00VCC0.7

CC

0.30

-1.00VCC0.7

CC

0.30

-1.00VCC0.7

CC

0.30

240

14.5
100

V

CC

0.5

V

CC

0.5

V

CC

0.5VV

UNITS

␮A
V
␮S

V
V

V
V

p/p

Note:-

1) The parameters Filter AmplifierV
related to Vcc.

OUT,IOUT

2) Applied via 1k resistors

3) These parameters are linear related to V

, Rectifier V

CC

and Comparator Threshold Voltage areall directly (linearly)

OUT

PROVISIONAL ISSUE A - OCTOBER 2001

2

ZLNB2012

ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):

T

amb= 25⬚C,VCC

SYMBOL PA RAMETER CONDITIONS

V

VHIGH

V

VLOW

V

VHIGH

V

VLOW

Note:-

1) Theparameters Filter Amplifier V
related to Vcc.

2) Applied via 1k resistors

3) These parameters are linear related to V

=5V

TD 1,2 Outputs
Voltage high

Voltage Low

BTD 1,2 Outputs
Voltage high

Voltage Low

ITD 1,2=-100␮A, Test Circuit 1,
Tone enabled

ITD 1,2=15mA, Test Circuit 1,
Tone disabled

IBTD 1,2=-100␮A, Test Circuit 1,
Tone disabled

IBTD 1,2=15mA, Test Circuit 1,
Tone enabled

OUT,IOUT

, RectifierV

CC

and ComparatorThreshold Voltage are all directly(linearly)

OUT

LIMITS

Min Typ Max

-1.00VCC-0.7

V

CC

0.3

-1.00VCC-0.7

V

CC

0.3

V

CC

0.5VV

V

CC

0.5VV

UNITS

PROVISIONAL ISSUE A - OCTOBER 2001

3

ZLNB2012

TEST CIRCUIT 1 (ZLNB2012 Pinout for QSOP16 package designator - Q16)

CF2

10nF

RP2

1.0k

BTD2
TD2
BHOR2
HOR2
ENA2
GND
FIN2

1

BTD1
TD1
BHOR1
HOR1
VCC
ENA1
FIN1

VPOL2 VPOL1

V1
5V

10nF

CF1

RP1

1.0k

V2

(See Note 1)

Note 1: V2 Characteristics

Type:- AC source
Frequency:- 22kHz
Voltage:- 300mVp/p Enabled

Zero Disabled

Tone Input (V2)

TD Outputs

Switching Delays

PROVISIONAL ISSUE A - OCTOBER 2001

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ZLNB2012

The following diagram shows a typical block diagram
for a twin universal LNB design. The ZLNB2012 device
provides the two polarity and two tone switches
required to decode the two independent receiver
feeds. Thedevice is also able todetect the absence of a
revceiver connection to either port of the LNB
providing all outputs to go high hence disabling of the
port. This allows the avoidance of unwanted signal
reflections from an unterminated down feed cable.

Horizontal
Antenna

Gain Stage
GaAs/HEMTFET

High Band

+

1

3

Mixer

+

Low Band

ASTRA

10.95 GHz-11.7 GHz
Standard Band

10.7 GHz-11.8 GHz
Enhanced Band

Bias Generator
ZNBG40XX
Series

Low Band

igh Band
H

High Band

+

4

Mixer

+

Low Band

Vertical
Antenna

2

Gain Stage
GaAs/HEMTFET

Additionally the frontend biasrequirements of theLNB
are providedby theZNBG4000 or ZNBG6000 offering a
very efficient and cost effective solution

Control Input
<=13V-Horizontal
>=14.5V-Vertical

ZLNB2012 Series

Dual H/V Switch

22kHz Switch

High Band
Horizontal

Low Band
Horizontal

PIN
Diode

&

Control

High Band
Vertical

Low Band
Vertical

MUX

DC Input
13-25V

H/V Output 1

IF down feed
950-1750 MHz

- Standard Band
950-2050 MHz

- Enhanced Band

H/V Output 2

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ZLNB2012

APPLICATION CIRCUIT EXAMPLES

The following circuit shows the additional components that will be used for polarisation mode and 22kHz tone
detection in typical ZLNB2012 application (ZLNB2012 Pinout for QSOP16 package designator - Q16).

1

RP2

1.0k

LNB Downfeed No.2

CF2

10nF

BTD2
TD2
BHOR2
HOR2
ENA2
GND
FIN2
VPOL2 VPOL1

BTD1
TD1
BHOR1
HOR1
VCC
ENA1
FIN1

CF1

10nF

Vcc

RP1

1.0k

LNB Downfeed No.1

ZLNB2012 PINOUT FOR QSOP16
PACKAGE DESIGNATOR - Q16

1

BTD2
TD2
BHOR2
HOR2
ENA2
GND
FIN2
VPOL2 VPOL1

BTD1
TD1
BHOR1
HOR1
VCC
ENA1
FIN1

ORDERING INFORMATION

Part Number Package Part Mark

ZLNB2012Q16 QSOP16 ZLNB2012

SAMPLE ORDERING INFORMATION

Part Number Package Part Mark

#ZLNB2012Q16 QSOP16 ZLNB2012

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FURTHER INFORMATION

Inputs Vpol1 and Vpol2 aredesigned to bewired to the
power inputs of an LNB via a high value (1K) resistors.
Input Vpol1 controls outputs HOR1, BHOR1 and ENA1.
Input Vpol2 controls outputs HOR2, BHOR2 and ENA2.
With either input voltage set at or below 14V, the
corresponding HOR pin will be active and the
corresponding BHOR pin will be the inverse of HOR.
With either input voltage at 14.5V or higher, the
corresponding HOR pin will be active and the
corresponding BHOR pin will be the inverse. Should
the voltage applied to either Vpol input fall below 8V,
the corresponding ENA (enable) pin will be low,
otherwise these outputs will remain high. Any input or
output may be left open circuit without any effect on
the remaining circuitry.

The ZLNB2012 includes all the circuitry necessary to
detect the presence of a 22kHz tone modulated on the
supply input to the LNB. The main elements of the
detector are an op-amp, a rectifier/smoother and a
comparitor. The op-amp has a pre-set internal
feedback resistor so that just a simple RC network
wired to the input gives user defined gain and low
frequency cut filter characteristics.

Output Truth Table

ZLNB2012

The RC network components also serve two other
purposes. The resistor provides overvoltage
protection for theVpol pinand thecapacitor minimises
tone interference of the Vpol threshold. The upper
frequency roll-off ofthe op-amphas beenset internally
at above 100kHz to allow the amplifier to be used with
other common tone switch frequencies.

The rectifier/smoother/comparitor function is provided
by a complex propriety circuit that allows the
ZLNB2012 to reliably detect wanted tones whilst
ignoring low frequency square wave switch box
signals, DiSEqC™ bursts and supply switching
transients common when using DiSEqC-2™ ready
set-top boxes. This is all achieved without the need for
any further external components. The threshold of the
comparitor is supply dependent, hence the gain of the
preceding op-amp mustbe adjustedin linewith supply
voltage.

The ZLNB2012 includes two independent channels, each containing a voltage detector and tone detector. The
following truth table applies to each channel:-

Tone Vpol TD BTD HOR BHOR ENA

Off ⭐14V Low High Low High High

Off ⭓14.5V Low High High Low High

On ⭐ 14V High Low Low High High

On ⭓14.5V High Low High Low High

- <8V - - Low High Low

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ZLNB2012

PACKAGE DIMENSIONS

QSOP16

DIM Millimetres Inches

MIN MAX MIN MAX

A 4.80 4.98 0.189 0.196

B 0.635 0.025 NOM

C 0.23 REF 0.009 REF

D 0.20 0.30 0.008 0.012

E 3.81 3.99 0.15 0.157

F 1.35 1.75 0.053 0.069

G 0.10 0.25 0.004 0.01

J 5.79 6.20 0.228 0.244

K0° 8° 0° 8°

© Zetex plc 2001

Zetex plc
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Chadderton
Oldham, OL9 8NP
United Kingdom
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PROVISIONAL ISSUE A - OCTOBER 2001

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