MODEL DG535 Digital Delay / Pulse Generator - SLAC

SETUP FOR OUTPUT STEPS UP TO15 VOLTSOption 04A, Fast Risetime (All rear panel outputs)LOAD = 50 ΩVARiable outputAMPLITUDE +0.5 to +4.0OFFSET -1 to -3 VOutput step= 5x AmplitudeAdjust for best pulse shapeOption 04B, Fast Falltime (All rear panel outputs)LOAD = 50 ΩVARiable outputAMPLITUDE -0.5 to -4.0 Output step = 5xAmplitudeOFFSET +1 to +3 V Adjust for best pulse shapeIMPORTANTDO NOT CONNECT THE FASTTRANSITION UNITS DIRECTLY TO THEREAR PANEL OUTPUTS: ALWAYS USEWITH THE BIAS TEE. OTHERWISE, THESRD CAN BE DAMAGED IF THE WRONGPOLARITY PULSE IS SPECIFIED OR IFTHE REVERSE BREAKDOWN VOLTAGEIS EXCEEDED. THE BIAS TEE CONTAINSA SERIES RESISTOR SO THAT THEDG535 CANNOT DAMAGE THE SRD.prevents the pulse from the rear panel outputfrom passing to the bias source.The bias tee is placed between rear panel outputand the fast transition-time unit. A series resistorin the bias tee will attenuate the output pulseand protect the SRD against output pulses of thewrong polarity. A good source for the biascurrent is the corresponding front panel output:attach the bias tee directly to the rear panel andconnect the bias input to the corresponding frontpanel output with a coax cable. Connect the fasttransition-time unit directly to the bias tee.The bias current for the fast transition-time unit mayalso come from an external bias circuit whichshould be limited so that the absolute maximumcurrent rating for the SRD (100 mA) is notexceeded. A forward bias current of about 40 mAwill be required for a 15 V output pulse.44