Internal/External Power Supply Considerations - Agilent Technologies 34945A User Manual

Non-Paired Channels
When channel pairing is not enabled (e.g. for single-coil drive), there are 16
channels per bank: 01-08/11-18 (bank 1) ... 61-68/71-78 (bank 4). Note that the
channel numbers within the bank are not consecutive.

Internal/External Power Supply Considerations

As shown in Figure 2-1, the channel drive source for switches and attenuators
in the 34945A RF Switch Platform is provided through the internal (or an
external) power supply. The internal/external supply must meet the quiescent
(continuous) and switching current requirements of the switches in your
application. The following sections provide additional information on these
requirements and the recommended configuration of these supplies.
Internal Supply
The master 34945EXT (Figure 2-1) can receive its power from either the
internal +24V supply of the 34945A or from an external supply. When using
the internal +24V supply, the quiescent (continuous) current draw must not
exceed 100 mA, with a switching pulse current that does not exceed 200 mA.
The duration of the switching pulse must be < 15 ms with a 25% duty cycle. The
remainder of the duty cycle (75%) allows recovery time for the supply to
provide the next pulse.
If the current limit is exceeded, an overcurrent condition can occur which
shuts down the internal supply. When this happens, you must remove the
device/condition causing the overcurrent and either send the
SYSTem:RMODule:RESet <slot>
cycle power on the 34980A mainframe. See "Overcurrent Conditions" in
Chapter 5 for more information.
The quiescent current requirement of the 34945EXTs themselves is accounted
for by the supply rating and is not included in quiescent current and switching
current calculations. Only the specified currents (quiescent, switching) of the
switch must be considered.
As an example, the Agilent 87104/87106A, B, C coaxial switches specify the
following:
Supply current (switching: pulse width =15 ms:Vcc = 24 VDC): 200 mA Nom
Supply current (quiescent): 50 mA Max
Agilent 34945A Microwave Switch/Attenuator Driver Module User's Guide
command to reset all 34945EXT modules, or
Hardware Configuration
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