User`s guide

18
34945A/34945EXT microwave
switch/attenuator driver
This module allows you to control switches
attenuators, and other devices external
to the 34980A. The 34945A/ 34945EXT
provides the power and control signals
for many of the most popular micro-
wave switches and attenuators. One
34945A/34945EXT combination can drive
up to 64 switch coils—that’s 32 standard
SPDT switches. The 34945A/EXT can be
extended by adding additional 34945EXT
boards. The first 34945EXT is powered by
the mainframe. You can add up to seven
additional 34945EXT boards with user sup-
plied power. Multiple switch operations are
performed in sequential order, or for faster,
simultaneous switching, you can connect an
external power supply to the 34945EXT.
The Y1150A-Y1155A distribution boards
enable simple connections to the external
switches. The distribution boards plug onto
the 34945EXT and are used to route the
power and control signals from the driver
module to the switches using standard
cables.
The 34945A/34945EXT also has sensing
capabilities that allows read back of the
actual position of the switch or attenuator.
DrivesignalsforLEDindicatorsarealso
provided to give a visual indication of the
switch position.
The following microwave switches and
attenuators are supported with the Y1150A-
Y1155A distribution boards:
•
N181x/U9397xseriesSPDTswitches
• 8762/3/4seriesSPDTswitches(screw
terminals)
• 8765xcoaxialswitches
• 8766x/8767x/8768xmultiportswitches
• 87104x/106x/L710xx/L720xx
multiport switches
• 87406xseriesmatrixswitches
• 87204x/206xseriesmultiportswitches
• 87606xseriesmatrixswitches
• 87222x/L7222transferswitches
• 849xand8490xseriesattenuators
• Otherswitchesanddevices
through individual screw
terminal connections
General specifications
34945EXT switch drive
(64 channels, low side drive mode)
Driver off voltage (max) 30 V
Driver off leakage current 500 uA
Driver on current (max) 600 mA
Driveronvoltage(max) 0.5V@600mA
34945EXT switch drive
(64 channels, TTL drive mode)
Hioutputvoltage 3V@I
out
=2mA
Looutputvoltage 0.4V@I
in
=20mA
LoinputCurrent 20mA
34945EXT position indicator sense inputs
Channels 64
Loinputvoltage(max) 0.8V
Hi input voltage (min) 2.5 V
Inputresistance >100kΩ@V
in
≤ 5 V
  >20kΩ@V
in
>5V
Maximum input voltage 30 V
34945EXT switch drive power supply
(34945EXT powered by 34945A)
Voltage 24 V nominal (external
power supply required for
switches needing more
than 24 V)
Current 100mAcontinuous+
200 mA (15 msec pulse,
  25%dutycycle)
34945EXT external power connection
Voltagerange 4.75Vto30V
Current limit 2 A
LED indicator (Current mode divers)
Channels 64
Supply voltage 5 V nominal
LEDdrivecurrent 5mAnominal
(prog 1-20 mA)
Driver compliance voltage 0.8 V
34945EXT dimensions
11.2” x 4.5” x 1.5” high with distribution boards
installed
Maximum 8 34945 Ext’s per mainframe
Switch drive control also available in
L4445AandL4490A/91ARFSwitch
Platform.
Note:SeeApplicationNote,“Configuring
anRF/MicrowaveSwitchSystem,”
literaturenumber5989-2272EN,forconfigu-
ration details.
Y1150A-Y1155A
distribution boards
required to control
switches (ordered separate)
34945EXT extender holds
4 distribution boar
34945A module
Figure 12. 34945A/34945EXT microwave switch/attenuator driver