ZLNB2006 Datasheet, PDF (1/11 Pages) Zetex Semiconductors – DUAL TONE AND POLARITY SWITCH LNB MULTIPLEX CONTROLLER

DUAL TONE AND POLARITY SWITCH
LNB MULTIPLEX CONTROLLER
ZLNB2006
ZLNB2009 ZLNB2010
DEVICE DESCRIPTION
The ZLNB2006/09/10 group of dual polarisation and
tone switch controller are part of a wide range of
satellite receiver LNB support circuits available from
Zetex. Each part features two completely independent
channels, each providing logic outputs to control LNB
polarisation selection, local oscillator selection and the
ZLNB2009/10 also provides downfeed disable. They
are intended for use in Twin Universal and Quad LNBs,
replacing many discrete components to save both
manufacturing cost and PCB size whilst improving
reliability.
The two polarisation control inputs of the
ZLNB2006/09/10 have a nominal threshold of 14.75V.
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 ZLNB2009/10 has a second
threshold set at 9.5V. An input voltage below this
threshold indicates “receiver not present”, switching
the relevant control channels high. This logic output
can be used to disable the associated downfeed driver,
eliminating any problems due to cable mismatch.
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 ZLNB2006/09/10 includes a separate tone
detector for each channel. Full control of detector
bandwidth and sensitivity is provided using two
external resistors and capacitors. In the ZLNB2006/9,
additional control of tone switch delays is provided to
assist with the rejection of low frequency control
signals intended for other systems.
Polarisation switch and tone detector outputs can
source and sink 10mA making them suitable to drive
TTL and CMOS logic, pin diodes and IF-amp supply
switching.
The ZLNB2006/09/10 operates from a single supply
which can be anything from 5-10V. Their quiescent
current is typically only 6mA and this does not change
significantly with load or logic state. They are available
in the space saving QSOP16 or QSOP20 surface mount
package.
FEATURES
• Dual polarisation switch
• Temperature compensated polarisation switch
threshold
• Transient resistant inputs
• Includes Receiver-Off detector (ZLNB2009/10)
• Dual tone switch
• User adjustable filter centre frequency and
bandwidth
• User adjustable tone switching delays
• Tone and Pol outputs are TTL, CMOS, Pin diode
and IF amp capable
• Wide supply operating range
• Low quiescent current
• Few external components
• Eliminates many discrete components
APPLICATIONS
• Twin Universal LNB
• Multi Feed Universal Lnb’s
• Twin Universal IF switch boxes
• LNB switch boxes
ISSUE 1 - APRIL 2002
1