Agilent Technologies L4400 - Manual (Page 196)

184 L4400 User’s Guide
7 L4445A Microwave Switch/Attenuator Driver
Simplified Connection Diagrams
Single Drive With Separate Position Indicators
The simplified schematic below illustrates the connection for a single drive
switch with separate position indicators. The position indicators for this
type of switch are independent relay contacts that are mechanically linked
to the RF switch position.
Even though this is a single drive switch, each switch state has its own
coil. The switch uses internal logic to open all paths except the one being
closed.
The RF paths are not shown in the simplified diagram. The coils are
driven in open collector mode. The position indicator is set so that a high
level indicates an active switch. The logic level of the position indicator
can be inverted using the
ROUTe:CHANnel:VERify:POLarity command.
The schematic shown is similar to the Agilent 87104A/B/C, 87106A/B/C,
and 87406B switches. Many other switches use this technique (both with
and without the position indicator).
34945EXT
Y1155A
Distribution
Board
Switch
6 5 4 3 2 1
1 3 4 5 6 2 Open
All
IND 1
+VI
+VR
DRV 1
Logic Gate
Sense
Pull Down
Resistor
Open Collector
Output Driver
To DRV 2 through 6 To DRV 7
To IND 2 through 6