Series CCP-18N
Low PIM Multi-Throw DC–3 GHz
Normally Open Coaxial Switch
COAX SWITCHES
GLOSSARY
Actuator
TD-Option
An actuator is the electromechanical mechanism that This option includes a decoder. The 3-bit parallel command
transfers the RF contacts from one position to another upon is decoded to internally select the appropriate position. See
DC command.
the logic tables. The TD-Option increases the Vsw supply
current demand by 50mA max at 28Vdc and +20°C.
Arc Suppression Diode
A diode is connected in parallel with the coil. This diode Performance Parameters vs Frequency
limits the “reverse EMF spike” generated when the coil de- Generally speaking, the RF performance of coaxial switches
energizes to 0.7 volts. The diode cathode is connected to is frequency dependent. With increasing frequency, VSWR
the positive side of the coil and the anode is connected to and insertion loss increase while isolation decreases. All
the negative side.
data sheets specify these three parameters as “worst case”
at the highest operating frequency. If the switch is to be
used over a narrow frequency band, better performance
Date Code
All switches are marked with either a unique serial number can be achieved.
or a date code. Date codes are in accordance with MIL-
STD-1285 Paragraph 5.2.5 and consist of four digits. Actuator Current vs Temperature
The first two digits define the year and the last two digits The resistance of the actuator coil varies as a function of
define the week of the year (YYWW). Thus, 1032 identifies temperature. There is an inverse relationship between the
switches that passed through final inspection during the operating temperature of the switch and the actuator drive
32nd week of 2010.
current. For switches operating at 28 VDC, the approximate
actuator drive current at temperature, T, can be calculated
using the equation:
Indicator
Indicators tell the system which position the switch is in.
Other names for indicators are telemetry contacts or tellback
circuit. Indicators are usually a set of internally mounted DC
contacts linked to the actuator. They can be wired to digital
input lines, status lights, or interlocks. Unless otherwise
specified, the maximum indicator contact rating is 30 Vdc,
50 mA, or 1.5 Watts into a resistive load.
I
A
I
=
T
[1 + .00385 (T-20)]
Where:
I
I
=
=
Actuator current at temperature, T
T
Room temperature actuator current –
see data sheet
A
Isolation
Isolation is the measure of the power level at the output
connector of an unconnected RF channel as referenced to
the power at the input connector. It is specified in dB below
the input power level.
T
=
Temperature of interest in °C
Magnetic Sensitivity
Multi-Throw Switch
An electro-mechanical switch can be sensitive to ferrous
A multi-throw switch is a switch with one input and three or materials and external magnetic fields. Neighboring ferrous
more output ports. The CCS-18 can switch a microwave materials should be permitted no closer than 0.5 inches and
signal to any of 2,3,4,5 or 6 output from a single common adjacent external magnetic fields should be limited to a flux
input.
density of less than 5 Gauss.
Switching Time
Switching time is the total interval beginning with the arrival
of the leading edge of the command pulse at the switch DC
input and ending with the completion of the switch transfer,
including contact bounce. It consists of three parts: (1)
inductive delay in the coil, (2) transfer time of the physical
movement of the contacts, and (3) the bounce time of the
RF contacts.
TTL Switch Driver Option
As a special option, switch drivers can be provided for both
failsafe and latching switches, which are compatible with
industry-standard low-power Schottky TTL circuits.
© 2013 TELEDYNE RELAYS
(800) 284-7007 • www.teledynecoax.com
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