Fairchild AN-7511 manual Pulse

Page 12

Application Note 7511

L = 100∝H

5V

A139P

1N914

PE-63385

D66EV7

10V

Q1

2k

10∝F

A114A

	A114A				15V
PULSE	A114A	100			D44D6
					D44D6

GENERATOR	TRIGGER		100	50	DS0026x2	A139M
	TRIGGER		100	50	DS0026x2	A139M
	1000pF			10		Q2
				10				V	CC
PULSE								V
PULSE
GENERATOR	A114A	1k		D38H1		VCE		VCLAMP
					RGE	VCE
							10
							10	(400V MAX)
Q1 = D66EV7					1-10k			(400V MAX)
Q1 = D66EV7
Q2 = DUT D94FQ4						0.02∝F

FIGURE 17. USE THIS LATCHING-CURRENT TESTER TO TEST IGTS NONDESTRUCTIVELY. Q1’S BASE-DRIVE PULSE WIDTH IS GREAT- ER THAN THAT OF THE IGT’S GATE DRIVE, SO THE IGT UNDER TEST IS SWITCHED THROUGH Q1 WHEN REVERSE-BIAS LATCH-UP OCCURS.

©2002 Fairchild Semiconductor Corporation

Application Note 7511 Rev. A1

Image 12

Contents Use Optoisolation To Avoid Ground Loops Take Some Driving LessonsApplication Note Pulse-Transformer Drive Is Cheap And EfficientPiezos Pare Prices Signal Path Isolator Isolate With Galvanic ImpunityPiezoelectric Couplers Provide 4-kV Isolation Fiber-Optic Drive Eliminates Interference VCO Timing Logic Use 6-Step Drive For Speed-InvariantTorque 165o Conduction Prevents Shoot-Through 1A/DIV This Circuit Provides Chopper Drive for the COPPER-WIRE Latch-Up Hints, Kinks and Caveats Forward-Bias Latch-UpPulse Crossvolt