7Microwave Switch/Attenuator Driver

Using Pulse Drive

To use the pulse drive mode, send the ROUTe:CHANnel:DRIVe:PULSe:MODE ON command or pair two channels with the ROUTe:CHANnel:DRIVe:PAIRed:MODE command. The diagram below illustrates the pulse drive for two channels (switches) and the relationship of the drive parameters to the power supply requirements.

T(Pulse)

T(Setttle)

 

 

T(Recovery)

 

Drive Ch 1

 

 

Drive Ch2

 

 

Start Drive

Start Drive

Channel 1 Position

Channel 1

Channel 2

Indicators Evaluated

As shown in the diagram, the drive is applied to channel 1 and held for the T(Pulse) time set using the ROUTe:CHANnel:DRIVe:PULSe:WIDTh command. Drive is applied to channel 2 only after a power supply recovery period has elapsed T(Recovery). The power supply recovery time is set using the ROUTe:CHANnel:DRIVe:TIMe:RECovery command. This parameter may be set individually for each channel or will default to 0.0 ms following either a SYSTem:RMODule:RESet or ROUTe:RMODule:BANK:PRESet command.

If you are verifying the channel operation (see page 149), you may also specify a T(Settle) parameter. During T(Settle) the switch is considered ‘busy’. This parameter ensures the switch has had time to change state before the verification. This parameter may be set individually for each channel or will default to 0.0 ms following either a SYSTem:RMODule:RESet or ROUTe:RMODule:BANK:PRESet command.

Unlike other switch modules, the L4445A will always pulse a channel in response to a ROUTe:OPEN or ROUTe:CLOSe command. For example, sending ROUTe:CLOSe to a channel three times in a row will result in three output pulses.

N O TE

A single drive channel operating in pulse mode with channel verification

(see page 149) turned off (default) will report the channel as ‘stateless’

 

 

and the ROUTe:CLOSe? query will return an error. Single drive pulsed

 

channels must have verification enabled

 

(ROUTe:CHANnel:VERify ON) to query the channel state using the

 

ROUTe:CLOSe? query.

 

 

148

L4400 User’s Guide

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Agilent Technologies L4400 manual Using Pulse Drive, Channels must have verification enabled