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

PROVISIONAL ISSUE A - OCTOBER 2001

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

ZLNB2012

ABSOLUTE MAXIMUM RATINGS

Supply Voltage -0.6V to 12V

Supply Current 500mA

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):

amb= 25⬚C,VCC

SYMBOL PA RAMETER CONDITIONS

POL

TPOL

SPOL

VHOR

HIGH

VHOR

LOW

VBHOR

HIGH

VBHOR

LOW

VEN

HIGH

VEN

LOW

OUT

inz

AG Amplifier Gain V FV

=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

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

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

POL

1= FIN2= Don’t Care

POL1=VPOL2

amb

2 Outputs

OUT

IHOR IHOR

OUT

IBHOR IBHOR

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

Filter Amplifier

Bias Voltage Input Impedance V

V Threshold

=0 1.75 1.95 2.15 V

fin

=100mV p/p 150 ⍀

FIN

=100mV p/p 30 V/mA

FIN

10014200

100 170 350 mV

912mA

14.25

-1.00VCC0.7

0.30

-1.00VCC0.7

0.30

-1.00VCC0.7

0.30

240

14.5 100

0.5

0.5VV

UNITS

␮A V ␮S

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

and Comparator Threshold Voltage areall directly (linearly)

OUT

PROVISIONAL ISSUE A - OCTOBER 2001

ZLNB2012

ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):

amb= 25⬚C,VCC

SYMBOL PA RAMETER CONDITIONS

VHIGH

VLOW

VHIGH

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

and ComparatorThreshold Voltage are all directly(linearly)

OUT

LIMITS

Min Typ Max

-1.00VCC-0.7

0.3

-1.00VCC-0.7

0.3

0.5VV

UNITS

PROVISIONAL ISSUE A - OCTOBER 2001

+ 5 hidden pages