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prevents the pulse from the rear panel output
from passing to the bias source.
The bias tee is placed between rear panel output
and the fast transition-time unit. A series resistor
in the bias tee will attenuate the output pulse
and protect the SRD against output pulses of the
wrong polarity. A good source for the bias
current is the corresponding front panel output:
attach the bias tee directly to the rear panel and
connect the bias input to the corresponding front
panel output with a coax cable. Connect the fast
transition-time unit directly to the bias tee.
The bias current for the fast transition-time unit may
also come from an external bias circuit which
should be limited so that the absolute maximum
current rating for the SRD (100 mA) is not
exceeded. A forward bias current of about 40 mA
will be required for a 15 V output pulse.
SETUP FOR OUTPUT STEPS UP TO
15 VOLTS
Option 04A, Fast Risetime (All rear panel outputs)
LOAD = 50
Ω
VARiable output
AMP0.5 to +4.0
Output step= 5x Amplitude
OFFSET -1 to -3 V Adjust for best pulse shape
Option 04B, Fast Falltime
(All rear panel outputs)
LOAD = 50
Ω
VARiable output
AMPLITUDE -0.5 to -4.0
Output step = 5x
Amplitude
1 to +3 V
Adjust for best pulse shape
IMPORTANT
DO NOT CONNECT THE FAST
TRANSITION UNITS DIRECTLY TO THE
REAR PANEL OUTPUTS: ALWAYS USE
WITH THE BIAS TEE. OTHERWISE, THE
SRD CAN BE DAMAGED IF THE WRONG
POLARITY PULSE IS SPECIFIED OR IF
THE REVERSE BREAKDOWN VOLTAGE
IS EXCEEDED. THE BIAS TEE CONTAINS
A SERIES RESISTOR SO THAT THE
DG535 CANNOT DAMAGE THE SRD.
