IM-275
INSTALLATION
MOUNTING: Each Programmable Step Attenuator is supplied with two mounting
screws (P/N MS35335-57). These screws will fit any of the mounting holes (4-40
UNC-2B x 0.22 MIN DP) located on either side of the attenuator.
RF CABLE INSTALLATION: Care should be taken to prevent strain on the inter-
connecting cables, since damage here may not always be apparent. Check the
attaching RF cables and the SMA connectors for signs of cracked insulation
and/or bent or worn pins prior to connection. Tests show that connectors must be
clean for accuracy and stability. This requires an inspection and cleaning of each
connector immediately before use. When cleaning precautions are observed reg-
ularly, connectors can maintain their stability for over several thousand
connection cycles. Weinschel recommends a torque value of 7 to 10 inch pounds
when connecting any RF cable to the attenuator's RF connectors.
DEVICE INTERFACE BUS (DIB) CONNECTOR WIRING: Figure 2 shows the
connectors contact pin numbering scheme and the signal designator for signal
present at each contact pin.
Name
VIN
Pin
Description
(1)
(1)
1
dc Supply Voltage, +12 to 15 V
PIN 14
PIN 13
VIN
GND
2
3,4
dc Supply Voltage, +12 to 15 V
dc Return
2
Data Bit 0 (lsb)/I C SDA
D0/SDA
D1/SCL
7
8
2
Data Bit 1//I C SCL
D2
D3
D4
D5
D6
D7
5
Data Bit 2
6
Data Bit 3
11
12
9
Data Bit 4
Data Bit 5
Data Bit 6
10
13
Data Bit 7 (msb)
Mode
Select
Parallel/Serial Mode Select
1=Parallel
2
0=I C
This pin has a 22K resistive pull-up to 5 V.
Leave unconnected for parallel mode operation.
/RST
14
Reset Input, low active
This pin has a 22K resistive pull-up to 5 V
Leave unconnected if not used.
2
PIN
PIN 1
Note: D0-D7 pins contain weak active pullups, capable of sourcing
approximately 150 mA.
(1) Voltage may be applied to either PIN 1 or 2 or both.
Figure 2. DIB Connector Wiring
4
APITECH [ API Technologies Corp ]
