Teccor® brand Thyristors Thyristor and Rectifier Testing

Teccor® brand Thyristors
Thyristor and Rectifier Testing Using Curve Tracers
Introduction
Limitations, Accuracy, and Correlation
One of the most useful and versatile instruments for
testing semiconductor devices is the curve tracer (CT).
Tektronix is the best known manufacturer of curve tracers
and produces four basic models: 575, 576, 577 and 370.
These instruments are specially adapted CRT display
screens with associated electronics such as power
supplies, amplifiers, and variable input and output functions
that allow the user to display the operating characteristics
of a device in an easy-to-read, standard graph form.
Operation of Tektronix CTs is simple and straightforward
and easily taught to non-technical personnel. Although
widely used by semiconductor manufacturers for design
and analytical work, the device consumer will find many
uses for the curve tracer, such as incoming quality control,
failure analysis, and supplier comparison. Curve tracers
may be easily adapted for go-no go production testing.
Tektronix also supplies optional accessories for specific
applications along with other useful hardware.
Although the curve tracer is a highly versatile device, it is
not capable of every test that one may wish to perform on
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breakdown, switching speeds, and others. Also, tests at
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accurately and without damaging the devices. A special
high-current test fixture available from Tektronix can extend
operation to 200 A pulsed peak. Kelvin contacts available
on the 576 and 577 eliminate inaccuracy in voltage
measured at high current (VTM) by sensing voltage drop due
to contact resistance and subtracting from the reading.
Tektronix Equipment
Although Tektronix no longer produces curve tracer model
575, many of the units are still operating in the field, and
it is still an extremely useful instrument. The 576, 577
and 370 are current curve tracer models and are more
streamlined in their appearance and operation. The 577 is a
less elaborate version of the 576, yet retains all necessary
test functions.
The following basic functions are common to all curve
tracers:
t 1PXFSTVQQMZsupplies positive DC voltage, negative
DC voltage, or AC voltage to bias the device. Available
power is varied by limiting resistors.
t 4UFQHFOFSBUPS supplies current or voltage in precise
steps to control the electrode of the device. The
number, polarity, and frequency of steps are selectable.
t )PSJ[POUBMBNQMJmFS displays power supply voltage as
applied to the device. Scale calibration is selectable.
t 7FSUJDBMBNQMJmFS displays current drawn from the
supply by the device. Scale calibration is selectable.
Curve tracer controls for beam position, calibration, pulse
operation, and other functions vary from model to model.
The basic theory of operation is that for each curve one
terminal is driven with a constant voltage or current and
the other one is swept with a half sinewave of voltage. The
driving voltage is stepped through several values, and a
different trace is drawn on each sweep to generate a family
of curves.
Accuracy of the unit is within the published manufacturer’s
specification. Allow the curve tracer to warm up and
stabilize before testing begins. Always expand the
horizontal or vertical scale as far as possible to increase
the resolution. Be judicious in recording data from the
screen, as the trace line width and scale resolution factor
somewhat limit the accuracy of what may be read. Regular
calibration checks of the instrument are recommended.
Some users keep a selection of calibrated devices on hand
to verify instrument operation when in doubt. Re-calibration
or adjustment should be performed only by qualified
personnel.
Often discrepancies exist between measurements
taken on different types of instrument. In particular,
most semiconductor manufacturers use high-speed,
computerized test equipment to test devices. They
test using very short pulses. If a borderline unit is then
measured on a curve tracer, it may appear to be out of
specification. The most common culprit here is heat.
When a semiconductor device increases in temperature
due to current flow, certain characteristics may change,
notably gate characteristics on SCRs, gain on transistors,
leakage, and so on. It is very difficult to operate the curve
tracer in such a way as to eliminate the heating effect.
Pulsed or single-trace operation helps reduce this problem,
but care should be taken in comparing curve tracer
measurements to computer tests. Other factors such as
stray capacitances, impedance matching, noise, and device
oscillation also may create differences.
Safety (Cautions and Warnings)
Adhere rigidly to Tektronix safety rules supplied with
each curve tracer. No attempt should be made to defeat
any of the safety interlocks on the device as the curve
tracer can produce a lethal shock. Also, older 575 models
do not have the safety interlocks as do the new models.
Take care never to touch any device or open the terminal
while energized.
WARNING: Devices on the curve tracer may be easily
damaged from electrical overstress.
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
Follow these rules to avoid destroying devices:
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of the device.
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minimum necessary to conduct the test.
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t 8BUDIGPSEFWJDFiSVOBXBZwEVFUPIFBUJOH
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small steps.
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General Test Procedures
Read all manuals before operating a curve tracer.
Perform the following manufacturer’s equipment check:
1. Turn on and warm up curve tracer, but turn off, or down,
all power supplies.
Model 576 Curve Tracer Procedures
The following test procedures are written for use with the
model 576 curve tracer. (Figure AN1006.1)
See “Model 370 Curve Tracer Procedure Notes” on page
AN1006-16 and “Model 577 Curve Tracer Procedure
Notes” on page AN1006-18 for setting adjustments
required when using model 370 and 577 curve tracers.
The standard 575 model lacks AC mode, voltage greater
than 200 V, pulse operations, DC mode, and step offset
controls. The 575 MOD122C does allow voltage up to 400
V, including 1500 V in an AC mode. Remember that at the
time of design, the 575 was built to test only transistors
and diodes. Some ingenuity, experience, and external
hardware may be required to test other types of devices.
For further information or assistance in device testing on
Tektronix curve tracers, contact the Littelfuse Applications
Engineering group.
2. Correctly identify terminals of the device to be tested.
Refer to the manufacturer’s guide if necessary.
3. Insert the device into the test fixture, matching the
device and test terminals.
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cover.
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6. Record results as required.
7. Disconnect all power to the device before removing.
Thyristor and Rectifier Testing Using Curve Tracers
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
TYPE 576
TEKTRONIX, INC.
CURVE TRACER
AN1006
AN1006
VERTICAL
PORTLAND, ORE, U.S.A.
PER
V
E
R
T
DIV
PER
DISPLAY OFFSET
H
O
R
I
Z
DIV
CRT
PER
S
T
E
P
()k
DIV
9m
PER
DIV
HORIZONTAL
HORIZONTAL
VOLTAGE CONTROL
Note: All Voltage
Settings Will Be
Referenced to
"Collector"
COLLECTOR SUPPLY
STEP GENERATOR
VARIABLE
COLLECTOR
SUPPLY
VOLTAGE RANGE
AMPLITUDE
MAX PEAK
POWER
(POWER DISSIPATION)
STEP/OFFSET
AMPLITUDE
(AMPS/VOLTS)
OFFSET
STEP/OFFSET
POLARITY
STEP FAMILY
RATE
TERMINAL
JACKS
C
C
B
B
E
E
TERMINAL
SELECTOR
MT2/ANODE
VARIABLE
COLLECTOR
SUPPLY VOLTAGE
GATE/TRIGGER
LEFT-RIGHT SELECTOR
FOR TERMINAL JACKS
MT1/CATHODE
KELVIN TERMINALS
USED WHEN
MEASURING VTM OR VFM
Figure AN1006.1
Tektronix Model 576 Curve Tracer
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
Teccor® brand Thyristors
AN1006
Power Rectifiers
The rectifier is a unidirectional device which conducts
when forward voltage (above 0.7 V) is applied.
To connect the rectifier:
Kelvin fixture is not used, an error in measurement of
VFM will result due to voltage drop in fixture. If a
Kelvin fixture is not available, Figure AN1006.3 shows
necessary information to wire a test fixture with Kelvin
connections.
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model 576, VFM cannot be tested at rated current
without a Tektronix model 176 high-current module.
The procedure below is done at IT(RMS) = 10 A (20 APK).
This test parameter allows the use of a standard curve
tracer and still provides an estimate of whether VFM is
within specification.
1. Connect Anode to Collector Terminal (C).
2. Connect Cathode to Emitter Terminal (E).
To begin testing, perform the following procedures.
Procedure 1:VRRM and IRM
To measure the VRRM and IRM parameter:
SOCKET
1. Set Variable Collector Supply Voltage Range to
1500 V.(2000 V on 370)
2. Set )PSJ[POUBM knob to sufficient scale to allow viewing
of trace at the required voltage level (100 V/DIV for 400
V and 600 V devices and 50 V/DIV for 200 V devices).
3. Set Mode to Leakage.
4. Set Vertical knob to 100 μA/DIV. (Due to leakage
setting, the CRT readout will be 100 nA per division.)
SOCKET PINS
One set of
pins wired to
Collector (C),
Base (B), and
Emitter (E)
Terminals
5. Set Terminal Selector to Emitter Grounded-Open
Base.
Socket used
must have two
sets of pins
6. Set Polarity to (-).
7. Set Power Dissipation to 2.2 W. (2 W on 370)
The pins which correspond to
the anode and cathode of the
device are wired to the terminals
marked CSENSE (MT2/Anode) and
E SENSE (MT1/Cathode). The gate
does not require a Kelvin
connection.
8. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
9. Increase Variable Collector Supply Voltage to the
rated VRRM of the device and observe the dot on the
CRT. Read across horizontally from the dot to the
vertical current scale. This measured value is the
leakage current. (Figure AN1006.2)
PER
V
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IRM
100
nA
DIV
H
O
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DIV
PER
S
T
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P
()k
DIV
9m
PER
DIV
Figure AN1006.2
IRM = 340 nA at VRRM = 600 V
Procedure 2:VFM
Before testing, note the following:
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Thyristor and Rectifier Testing Using Curve Tracers
Instructions for Wiring Kelvin Socket
To measure the VFM parameter:
1. Set Variable Collector Supply Voltage Range to 15
Max Peak Volts. (16 V on 370)
2. Set )PSJ[POUBM knob to 0.5 V/DIV.
3. Set Mode to Norm.
PER
VRRM
Figure AN1006.3
100
V
4. Set Vertical knob to 2 A/DIV.
5. Set Power Dissipation to 220 W (100 W on 577).
6. Set Polarity to (+).
7. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
8. Increase Variable Collector Supply Voltage until
current reaches 20 A.
WARNING: Limit test time to 15 seconds maximum.
To measure VFM, follow along horizontal scale to the point
where the trace crosses the 20 A axis. The distance from
the left-hand side of scale to the crossing point is the VFM
value. (Figure AN1006.4)
Note: Model 370 current is limited to 10 A.
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Note: The CRT screen readout should show 1% of the
maximum leakage current if the vertical scale is divided by
1,000 when leakage current mode is used.
PER
V
E
R
T
VFM
2
A
Procedure 2:VDRM / IDRM
DIV
PER
H
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Z
500
mV
DIV
IT
PER
S
T
E
P
()k
DIV
9m
PER
DIV
Figure AN1006.4
VFM = 1 V at IPK = 20 A
To measure the VDRM and IDRM parameter:
1. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
2. Set Variable Collector Supply Voltage to the rated
VDRM of the device and observe the dot on CRT. Read
across horizontally from the dot to the vertical current
scale. This measured value is the leakage current.
(Figure AN1006.5)
WARNING: Do NOT exceed VDRM/VRRM rating of SCRs,
Triacs, or Quadracs. These devices can be damaged.
SCRs
PER
SCRs are half-wave unidirectional rectifiers turned on when
current is supplied to the gate terminal. If the current
supplied to the gate is to be in the range of 12 μA and 500
μA, then a sensitive SCR is required; if the gate current is
between 1 mA and 50 mA, then a non-sensitive SCR is
required.
V
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PER
H
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VDRM
PER
S
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IDRM
1. Connect Anode to Collector Terminal (C).
2. Connect Cathode to Emitter Terminal (E).
Note: When sensitive SCRs are being tested, a 1 kΩ
resistor must be connected between the gate and the
cathode, except when testing IGT.
Figure AN1006.5
To begin testing, perform the following procedures.
Procedure 3: VRRM / IRRM
Procedure 1:VDRM / VRRM / IDRM / IRRM
To measure the VRRM and IRRM parameter:
To measure the VDRM7RRM*DRM, and IRRM parameter:
1. Set Polarity to (-).
2. Set )PSJ[POUBM knob to sufficient scale to allow viewing
of trace at the required voltage level. (The 100 V/DIV
scale should be used for testing devices having a VDRM
value of 600 V or greater; the 50 V/DIV scale for testing
parts rated from 300 V to 500 V, and so on.)
100
V
DIV
To connect the rectifier:
1. Set Variable Collector Supply Voltage Range to
appropriate Max Peak Volts for device under test.
(Value selected should be equal to or greater than the
device’s VDRM rating.)
100
nA
DIV
()k
DIV
9m
PER
DIV
IDRM = 350 nA at VDRM = 600 V
2. Repeat Steps 1 and 2 (VDRM, IDRM) except substitute VRRM
value for VDRM. (Figure AN1006.6)
PER
V
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IRRM
100
nA
DIV
PER
VRRM
H
O
R
I
Z
100
V
DIV
3. Set Mode to Leakage.
PER
S
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4. Set Polarity to (+).
5. Set Power Dissipation to 0.5 W.(0.4 W on 370)
()k
DIV
9m
PER
DIV
6. Set Terminal Selector to Emitter Grounded-Open
Base.
7. Set Vertical knob to approximately ten times the
maximum leakage current (IDRM, IRRM) specified for the
device. (For sensitive SCRs, set to 50 μA.)
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Figure AN1006.6
IRRM = 340 nA at VRRM = 600 V
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
Procedure 4: VTM
To measure the VTM parameter:
1. Set Terminal Selector to Step Generator-Emitter
Grounded.
2. Set Polarity to (+).
PER
V
E
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T
2
A
DIV
PER
VTM
3. Set Step/Offset Amplitude to twice the maximum IGT
rating of the device (to ensure the device turns on). For
sensitive SCRs, set to 2 mA.
H
O
R
I
Z
500
mV
DIV
PER
S
T
E
P
IPK
4. Set Max Peak Volts to 15 V. (16 V on 370)
()k
DIV
9m
PER
DIV
5. Set Offset by depressing 0 (zero).
6. Set Rate by depressing Norm.
100
mA
20
7. Set Step Family by depressing Rep (repetitive).
8. Set Mode to DC.
Figure AN1006.7
9. Set )PSJ[POUBM knob to 0.5 V/DIV.
Procedure 5: IH
10. Set Power Dissipation to 220 W (100 W on 577).
To measure the IH parameter:
11. Set Number of Steps to 1. (Set steps to 0 (zero) on
370.)
12. Set Vertical knob to a sufficient setting to allow the
viewing of 2 times the IT(RMS) rating of the device (IT(peak))
on CRT.
Before continuing with testing, note the following:
(1) Due to the excessive amount of power that can be
generated in this test, only parts with an IT(RMS) rating
of 6 A or less should be tested on standard curve
tracer. If testing devices above 6 A, a Tektronix
model 176 high-current module is required.
(2) A Kelvin test fixture is required for this test. If a
Kelvin fixture is not used, an error in measurement
of VTM will result due to voltage drop in the fixture.
If a Kelvin fixture is not available, Figure AN1006.3
shows necessary information to wire a test fixture
with Kelvin connectors.
13. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
14. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak), which is twice the IT(RMS)
rating of theSCR under test.
Note: Model 370 current is limited to 10 A.
WARNING: Limit test time to 15 seconds maximum
after the Variable Collector Supply has been set to
IT(peak), After the Variable Collector Supply Voltage has
been set to IT(peak), the test time can automatically be
shortened by changing Step Family from repetitive to
single by depressing the Single button.
To measure VTM, follow along horizontal scale to the point
where the trace crosses the IT(peak) value. The distance from
the left-hand side of scale to the intersection point is the
VTM value. (Figure AN1006.7)
Thyristor and Rectifier Testing Using Curve Tracers
VTM = 1.15 V at IT(peak) = 12 A
1. Set Polarity to (+).
2. Set Power Dissipation to 2.2 W. (2 W on 370)
3. Set Max Peak Volts to 75 V. (80 V on 370)
4. Set Mode to DC.
5. Set )PSJ[POUBM knob to Step Generator.
6. Set Vertical knob to approximately 10 percent of the
maximum IH specified.
Note: Due to large variation of holding current values, the
scale may have to be adjusted to observe holding
current.
7. Set Number of Steps to 1.
8. Set Offset by depressing 0(zero). (Press Aid and
Oppose at the same time on 370.)
9. Set Step/Offset Amplitude to twice the maximum IGT
of the device.
10. Set Terminal Selector to Step Generator-Emitter
Grounded.
11. Set Step Family by depressing Single.
12. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
13. Increase Variable Collector Supply Voltage to
maximum position (100).
14. Set Step Family by depressing Single. (This could
possibly cause the dot on CRT to disappear, depending
on the vertical scale selected.)
15. Change Terminal Selector from Step GeneratorEmitter Grounded to Open Base-Emitter Grounded.
16. Decrease Variable Collector Supply Voltage to the
point where the line on the CRT changes to a dot. The
position of the beginning point of the line, just before
the line becomes a dot, represents the holding current
value. (Figure AN1006.8)
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
PER
V
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PER
DIV
DIV
PER
PER
H
O
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Z
H
O
R
I
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DIV
DIV
PER
PER
S
T
E
P
IH
Figure AN1006.8
V
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500
A
10
A
S
T
E
P
IGT
()k
DIV
9m
PER
DIV
IH = 1.2 mA
50
mA
()k
DIV
9m
PER
DIV
Figure AN1006.9
5 K
IGT = 25 μA
Procedure 6: IGT and VGT
Procedure 8: VGT
To measure the IGT and VGT parameter:
To measure the VGT parameter:
1. Set Polarity to (+).
1. Set Offset Multiplier to 0 (zero). (Press Aid and
Oppose at the same time on 370.)
2. Set Number of Steps to 1.
3. Set Offset by depressing Aid.
2. Set Step Offset Amplitude to 20% rated VGT.
4. Set Offset Multiplier to 0 (zero). (Press Aid and
Oppose at the same time on 370.)
3. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
5. Set Terminal Selector to Step Generator-Emitter
Grounded.
4. Gradually increase Offset Multiplier until device
reaches the conduction point. (Figure AN1006.10)
Measure VGT by following horizontal axis to the point
where the vertical line crosses axis. This measured
value is VGT. (On 370, VGT will be numerically displayed
on screen, under offset value.)
6. Set Mode to Norm.
7. Set Max Peak Volts to 15 V. (16 V on 370)
8. Set Power Dissipation to 2.2 W. (2 W on 370) For
sensitive SCRs, set at 0.5 W. (0.4 W on 370)
9. Set )PSJ[POUBM knob to 2 V/DIV.
PER
10. Set Vertical knob to 50 mA/DIV.
V
E
R
T
11. Increase Variable Collector Supply Voltage until
voltage reaches 12 V on CRT.
50
mA
DIV
PER
H
O
R
I
Z
12. After 12 V setting is completed, change )PSJ[POUBM
knob to Step Generator.
DIV
PER
Procedure 7: IGT
VGT
To measure the IGT parameter:
1. Set Step/Offset Amplitude to 20% of maximum rated
IGT.
Note: RGK should be removed when testing IGT
2. Set Left-Right Terminal Jack Selector to correspond
with location of the test fixture.
Figure AN1006.10
S
T
E
P
200
mV
()k
DIV
9m
PER
DIV
250m
VGT = 580 mV
3. Gradually increase Offset Multiplier until device
reaches the conduction point. (Figure AN1006.9)
Measure IGT by following horizontal axis to the point
where the vertical line crosses axis. This measured
value is IGT. (On 370, IGT will be numerically displayed on
screen under offset value.)
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
Triacs
current. (Figure AN1006.11)
Triacs are full-wave bidirectional AC switches turned on
when current is supplied to the gate terminal of the device.
If gate control in all four quadrants is required, then a
sensitive gate Triac is needed, whereas a standard Triac
can be used if gate control is only required in Quadrants I
through III.
PER
V
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PER
H
O
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100
V
DIV
To connect the Triac:
1. Connect the Gate to the Base Terminal (B).
50
nA
DIV
PER
S
T
E
P
VDRM
IDRM
2. Connect MT1 to the Emitter Terminal (E).
3. Connect MT2 to the Collector Terminal (C).
()k
DIV
9m
PER
DIV
To begin testing, perform the following procedures.
Figure AN1006.11
Procedure 1: (+)VDRM, (+)IDRM, (-)VDRM, (-)IDRM
Note: The (+) and (-) symbols are used to designate the
polarity MT2 with reference to MT1.
To measure the (+)VDRM, (+)IDRM, (-)VDRM, and (-)IDRM
parameter:
1. Set Variable Collector Supply Voltage Range to
appropriate Max Peak Volts for device under test.
(Value selected should be equal to the device’s VDRM
rating.)
WARNING: DO NOT exceed VDRM/VRRM rating of
SCRs, Triacs, or Quadracs. These devices can be
damaged.
2. Set )PSJ[POUBM knob to sufficient scale to allow viewing
of trace at the required voltage level. (The 100 V/DIV
scale should be used for testing devices having a VDRM
rating of 600 V or greater; the 50 V/DIV scale for testing
parts rated from 30 V to 500 V, and so on.)
3. Set Mode to Leakage.
4. Set Polarity to (+).
5. Set Power Dissipation to 0.5 W. (0.4 W on 370)
6. Set Terminal Selector to Emitter Grounded-Open
Base.
7. Set Vertical knob to ten times the maximum leakage
current (IDRM) specified for the device.
Note: The CRT screen readout should show 1% of the
maximum leakage current. The vertical scale is divided by
1,000 when leakage mode is used.
(+)IDRM = 205 nA at (+)VDRM = 600 V
Procedure 3: (-)VDRM, (-)IDRM
To measure the (-)VDRM and (-)IDRM parameter:
1. Set Polarity to (-).
2. Repeat Procedures 1 and 2. (Read measurements from
upper right corner of the screen.)
Procedure 4: VTM (Forward and Reverse)
To measure the VTM (Forward and Reverse) parameter:
1. Set Terminal Selector to Step Generator-Emitter
Grounded.
2. Set Step/Offset Amplitude to twice the maximum IGT
rating of the device (to insure the device turns on).
3. Set Variable Collector Supply Voltage Range to 15 V
Max Peak volts. (16 V on 370)
4. Set Offset by depressing 0 (zero).
5. Set Rate by depressing Norm.
6. Set Step Family by depressing Rep (Repetitive).
7. Set Mode to Norm.
8. Set )PSJ[POUBM knob to 0.5 V/DIV.
9. Set Power Dissipation to 220 W (100 W on 577).
10. Set Number of Steps to 1.
11. Set Step/Offset Polarity to non-inverted (button
extended; on 577 button depressed).
Procedure 2: (+)VDRM, (+)IDRM
12. Set Vertical knob to a sufficient setting to allow the
viewing of 1.4 times the IT(RMS) rating of the device [IT(peak)
on CRT].
To measure the (+)VDRM and (+)IDRM parameter:
Note the following:
1. Set Left-Right Terminal Jack Selector to correspond with
location of the test fixture.
t %VFUPUIFFYDFTTJWFBNPVOUPGQPXFSUIBUDBOCF
generated in this test, only parts with an IT(RMS) rating of
8 A or less should be tested on standard curve tracer. If
testing devices above 8 A, a Tektronix model 176 highcurrent module is required.
2. Increase Variable Collector Supply Voltage to the rated
VDRM of the device and observe the dot on the CRT.
Read across horizontally from the dot to the vertical
current scale. This measured value is the leakage
Thyristor and Rectifier Testing Using Curve Tracers
t ",FMWJOUFTUmYUVSFJTSFRVJSFEGPSUIJTUFTU*GB
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Kelvin fixture is not used, an error in measurement of
VTM will result due to voltage drop in fixture. If a
Kelvin fixture is not available, Figure AN1006.3 shows
necessary information to wire a test fixture with Kelvin
connections.
Procedure 7: IH(Forward and Reverse)
To measure the IH (Forward and Reverse) parameter:
1. Set Step/Offset Amplitude to twice the IGT rating of
the device.
2. Set Power Dissipation to 10 W.
Procedure 5: VTM (Forward)
3. Set Max Peak Volts to 75 V. (80 V on 370)
To measure the VTM (Forward) parameter:
4. Set Mode to DC.
1. Set Polarity to (+).
5. Set )PSJ[POUBM knob to Step Generator.
2. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
6. Set Vertical knob to approximately 10% of the
maximum IH specified.
3. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak), which is 1.4 times IT(RMS)
rating of the Triac under test.
Note: Model 370 current is limited to 10 A.
Note: Due to large variation of holding current values,
the scale may have to be adjusted to observe holding
current.
7. Set Number of Steps to 1.
WARNING: Limit test time to 15 seconds maximum.
After the Variable Collector Supply Voltage has been
set to IT(peak), the test time can automatically be set
to a short test time by changing Step Family from
repetitive to single by depressing the Single button.
To measure VTM, follow along horizontal scale to the point
where the trace crosses the IT(peak) value. The distance from
the left-hand side of scale to the crossing point is the VTM
value. (Figure AN1006.12)
8. Set Step/Offset Polarity to non-inverted (button
extended, on 577 button depressed).
9. Set Offset by depressing 0 (zero). (Press Aid and
Oppose at same time on 370.)
10. Set Terminal Selector to Step Generator-Emitter
Grounded.
Procedure 8: IH(Forward)
To measure the IH (Forward) parameter:
1. Set Polarity to (+).
2. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
PER
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2
A
DIV
PER
H
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VTM
500
mV
DIV
PER
IPK
S
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P
()k
DIV
9m
PER
DIV
Figure AN1006.12
100
mA
20
3. Increase Variable Collector Supply Voltage to
maximum position (100).
4. Set Step Family by depressing Single.
This could possibly cause the dot on the CRT to
disappear, depending on the vertical scale selected).
5. Decrease Variable Collector Supply Voltage to the
point where the line on the CRT changes to a dot. The
position of the beginning point of the line, just before
the line becomes a dot, represents the holding current
value. (Figure AN1006.13)
VTM (forward) = 1.1 V at IPK = 11.3 A (8 A rms)
PER
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Procedure 6: VTM (Reverse)
DIV
To measure the VTM (Reverse) parameter:
PER
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1. Set Polarity to (-).
DIV
2. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
3. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak).
4. Measure VTM(Reverse) similar to Figure AN1006.12, except
from upper right hand corner of screen.
PER
S
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E
P
©2008 Littelfuse, Inc.
()k
DIV
9m
PER
DIV
IH
Figure AN1006.13
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
5
mA
50
mA
100m
IH (Forward) = 8.2 mA
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
Procedure 9: IH(Reverse)
To measure the IH (Reverse) parameter:
PER
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1. Set Polarity to (-).
50
mA
DIV
2. Repeat Procedure 7 measuring IH(Reverse). (Read
measurements from upper right corner of the screen.)
PER
H
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DIV
Procedure 10: IGT
PER
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To measure the IGT parameter:
1. Set Polarity to (+).
IGT
()k
DIV
9m
PER
DIV
2. Set Number of Stepsto 1. (Set number of steps to 0
(zero) on 370.)
3. Set Offset by depressing Aid. (On 577, also set Zero
button to Offset. Button is extended.)
4. Set Offset Multiplier to 0 (zero). (Press Aid and
Oppose at same time on 370.)
5. Set Terminal Selector to Step Generator-Emitter
Grounded.
Figure AN1006.14
5
mA
10
IGT in Quadrant I = 18.8 mA
Procedure 12: IGT - Quadrant II [MT2 (+) Gate (-)]
To measure the IGT - Quadrant II parameter:
6. Set Mode to Norm.
1. Set Step/Offside Polarity by depressing Invert
(release button on 577).
7. Set Max Peak Volts to 15 V. (16 V on 370)
2. Set Polarity to (+).
8. Set Power Dissipation to 10 W.
9. Set Step Family by depressing Single.
3. Set observed dot to bottom right corner of CRT grid by
turning the horizontal position knob. When Quadrant II
testing is complete, return dot to original position.
10. Set )PSJ[POUBM knob to 2 V/DIV.
4. Repeat Procedure 11.
11. Set Vertical knob to 50 mA/DIV.
12. Set Step/Offset Polarity to non-inverted position
(button extended, on 577 button depressed).
Procedure 13: IGT - Quadrant III [MT2 (-) Gate (-)]
To measure the IGT - Quadrant III parameter:
13. Set Variable Collector Supply Voltage until voltage
reaches 12 V on CRT.
1. Set Polarity to (-).
14. After 12 V setting is completed, change )PSJ[POUBM
knob to Step Generator.
2. Set Step/Offset Polarity to non-inverted position
(button extended, on 577 button depressed).
3. Repeat Procedure 11. (Figure AN1006.15)
Procedure 11: IGT - Quadrant I [MT2 (+) Gate (+)]
To measure the IGT - Quadrant I parameter:
PER
1. Set Step/Offset Amplitude to approximately 10% of
rated IGT.
IGT
2. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
50
mA
DIV
PER
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3. Gradually increase Offset Multiplier until device
reaches conduction point. (Figure AN1006.14) Measure
IGT by following horizontal axis to the point where the
vertical line passes through the axis. This measured
value is IGT. (On 370, IGT is numerically displayed on
screen under offset value.)
DIV
PER
S
T
E
P
()k
DIV
9m
PER
DIV
Figure AN1006.15
Thyristor and Rectifier Testing Using Curve Tracers
V
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5
mA
10
IGT in Quadrant III = 27 mA
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Procedure 14: IGT - Quadrant IV [MT2 (-) Gate (+)]
PER
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To measure the IGT - Quadrant IV parameter:
50
mA
DIV
1. Set Polarity to (-).
PER
2. Set Step/Offset Polarity by depressing Invert (release
button on 577).
H
O
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I
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VGT
DIV
3. Set observed dot to top left corner of CRT grid by
turning the )PSJ[POUBM position knob. When Quadrant
IV testing is complete, return dot to original position.
PER
4. Repeat Procedure 11.
()k
DIV
9m
PER
DIV
Procedure 15: VGT
To measure the VGT parameter:
1. Set Polarity to (+).
2. Set Number of Steps to 1. (Set steps to 0 (zero) on
370.)
500
mV
S
T
E
P
Figure AN1006.16
100m
VGT in Quadrant I = 780 mV
Procedure 17: VGT - Quadrant II [MT2 (+) Gate (-)]
To measure the VGT - Quadrant II parameter:
3. Set Offset by depressing Aid. (On 577, also set 0 (zero)
button to Offset. Button is extended.)
1. Set Step/Offset Polarity by depressing Invert (release
button on 577).
4. Set Offset Multiplier to 0 (zero). (Press Aid and
Oppose at same time on 370.)
2. Set Polarity to (+).
5. Set Terminal Selector to Step Generator-Emitter
Grounded.
3. Set observed dot to bottom right corner of CRT grid by
turning the )PSJ[POUBM position knob. When Quadrant II
testing is complete, return dot to original position.
6. Set Mode to Norm.
4. Repeat Procedure 16.
7. Set Max Peak Volts to 15 V. (16 V on 370)
8. Set Power Dissipation to 10 W.
Procedure 18: VGT - Quadrant III [MT2 (-) Gate (-)]
9. Set Step Family by depressing Single.
To measure the VGT - Quadrant III parameter:
10. Set )PSJ[POUBM knob to 2 V/DIV.
1. Set Polarity to (-).
11. Set Step/Offset Polarity to non-inverted position
(button extended, on 577 button depressed).
2. Set Step/Offset Polarity to non-inverted position
(button extended, on 577 button depressed).
12. Set Current Limit to 500 mA (not available on 577).
3. Repeat Procedure 16. (Figure AN1006.17)
13. Increase Variable Collector Supply Voltage until
voltage reaches 12 V on CRT.
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14. After 12 V setting is complete, change )PSJ[POUBM knob
to Step Generator.
VGT
Procedure 16: VGT - Quadrant I [MT2 (+) Gate (+)]
PER
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To measure the VGT - Quadrant I parameter:
DIV
PER
1. Set Step/Offset Amplitude to 20% of rated VGT.
S
T
E
P
2. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
3. Gradually increase Offset Multiplier until device
reaches conduction point. (Figure AN1006.16) Measure
VGT by following horizontal axis to the point where the
vertical line passes through the axis. This measured
value will be VGT. (On 370, VGT will be numerically
displayed on screen under offset value.)
50
mA
DIV
()k
DIV
9m
PER
DIV
Figure AN1006.17
500
mV
100m
VGT in Quadrant III = 820 mV
Procedure 19: VGT - Quadrant IV [MT2 (-) Gate (+)]
To measure the VGT - Quadrant IV parameter:
1. Set Polarity to (-).
2. Set Step/Offset Polarity by depressing Invert (release
button on 577).
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
3. Set observed dot to top left corner of CRT grid by
turning the )PSJ[POUBM position knob. When testing is
complete in Quadrant IV, return dot to original position.
4. Repeat Procedure 16.
vertical current scale.) This measured value is the leakage
current. (Figure AN1006.18)
WARNING: Do NOT exceed VDRM/VRRM rating of SCRs,
Triacs, or Quadracs. These devices can be damaged.
Quadracs
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Quadracs are simply Triacs with an internally-mounted
DIAC. As with Triacs, Quadracs are bidirectional AC
switches which are gate controlled for either polarity of
main terminal voltage.
50
nA
DIV
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50
V
DIV
To connect the Quadrac:
1. Connect Trigger to Base Terminal (B).
2. Connect MT1 to Emitter Terminal (E).
PER
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VDRM
IDRM
3. Connect MT2 to Collector Terminal (C).
()k
DIV
9m
PER
DIV
To begin testing, perform the following procedures.
Figure AN1006.18
Procedure 1: (+)VDRM, (+)IDRM, (-)VDRM, (-)IDRM
Note: The (+) and (-) symbols are used to designate the
polarity of MT2 with reference to MT1.
To measure the (+)VDRM, (+)IDRM, (-)VDRM, and (-)IDRM
parameter:
1. Set Variable Collector Supply Voltage Range to
appropriate Max Peak Volts for device under test.
(Value selected should be equal to or greater than the
device’s VDRM rating).
(+)IDRM = 51 nA at (+)VDRM = 400 V
Procedure 3: (-)VDRM and (-)IDRM
To measure the (-)VDRM and (-)IDRM parameter:
1. Set Polarity to (-).
2. Repeat Procedures 1 and 2. (Read measurements from
upper right corner of screen).
Procedure 4: VBO, IBO,VBO
(Quadrac Trigger DIAC or Discrete DIAC)
2. Set )PSJ[POUBM knob to sufficient scale to allow viewing
of trace at the required voltage level. (The7%*7
scale should be used for testing devices having a VDRM
rating of 600 V or greater; the 50 V/DIV scale for testing
parts rated from 300 V to 500 V, and so on).
1. Connect MT1 to Emitter Terminal (E).
3. Set Mode to Leakage.
3. Connect Trigger Terminal to MT2 Terminal through a
10 Ω resistor.
4. Set Polarity to (+).
5. Set Power Dissipation to 0.5 W. (0.4 W on 370)
To connect the Quadrac:
2. Connect MT2 to Collector Terminal (C).
To measure the VBO, IBO, and ΔVBO parameter:
6. Set Terminal Selector to Emitter Grounded-Open
Base.
1. Set Variable Collector Supply Voltage Range to 75
Max Peak Volts.(80 V on 370)
7. Set Vertical knob to ten times the maximum leakage
current (IDRM) specified for the device.
2. Set )PSJ[POUBM knob to 10 V/DIV.
Note: The CRT readout should show 1% of the
maximum leakage current. The vertical scale is divided
by 1,000 when the leakage mode is used.
Procedure 2: (+)VDRM and (+)IDRM
To measure the (+)VDRM and (+)IDRM parameter:
3. Set Vertical knob to 50 μA/DIV.
4. Set Polarity to AC.
5. Set Mode to Norm.
6. Set Power Dissipation to 0.5 W. (0.4 W on 370)
7. Set Terminal Selector to Emitter Grounded-Open
Base.
1. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
2. Increase Variable Collector Supply Voltage to the
rated VDRM of the device and observe the dot on the
CRT. (Read across horizontally from the dot to the
Thyristor and Rectifier Testing Using Curve Tracers
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Procedure 5: VBO (Positive and Negative)
Note the following:
To measure the VBO (Positive and Negative) parameter:
1. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
2. Set Variable Collector Supply Voltage to 55 V (65
V on 370) and apply voltage to the device under test
(D.U.T.) using the Left Hand Selector Switch. The peak
voltage at which current begins to flow is the VBO value.
(Figure AN1006.19)
Due to the excessive amount of power that can be
generated in this test, only parts with an IT(RMS) rating of
8 A or less should be tested on standard curve tracer. If
testing devices above 8 A, a Tektronix model 176 highcurrent module is required.
A Kelvin test fixture is required for this test. If a
Kelvin fixture is not used, an error in measurement
of VTM will result due to voltage drop in fixture. If a
Kelvin fixture is not available, Figure AN1006.3 shows
necessary information to wire a test fixture with Kelvin
connections.
PER
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50
A
DIV
VBO
+IBO
PER
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10
V
DIV
PER
IBO
+VBO
S
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()k
DIV
9m
PER
DIV
Figure AN1006.19
(+)VBO = 35 V; (-)VBO = 36 V; (±)IBO"
Procedure 6: IBO (Positive and Negative)
To measure the IBO (Positive and Negative) parameter, at the VBO
point, measure the amount of device current just before
the device reaches the breakover point. The measured
current at this point is the IBO value.
Note: If IBO is less than 10 μA, the current cannot readily be
seen on curve tracer.
To measure the VTM (Forward and Reverse) parameter:
1. Set Terminal Selector to Emitter Grounded-Open
Base.
2. Set Max Peak Volts to 75 V. (80 V on 370)
3. Set Mode to Norm.
4. Set )PSJ[POUBM knob to 0.5 V/DIV.
5. Set Power Dissipation to 220 watts (100 watts on a
577).
6. Set Vertical knob to a sufficient setting to allow the
viewing of 1.4 times the IT(RMS) rating of the device IT(peak)
on the CRT.
Procedure 9: VTM(Forward)
To measure the VTM (Forward) parameter:
1. Set Polarity to (+).
2. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
3. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak), which is 1.4 times the IT(RMS)
rating of the Triac under test.
Procedure 7: ΔVBO (Voltage Breakover Symmetry)
Note: Model 370 current is limited to 10 A.
To measure the ΔVBO (Voltage Breakover Symmetry) parameter:
WARNING: Limit test time to 15 seconds maximum.
1. Measure positive and negative VBO values per
Procedure 5.
2. Subtract the absolute value of VBO (-) from VBO (+).
4. To measure VTM, follow along horizontal scale to the
point where the trace crosses the IT(peak) value. This
horizontal distance is the VTM value. (Figure AN1006.20)
The absolute value of the result is:
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ΔVBO = [ I+VBO I - I -VBO I ]
1
A
DIV
Procedure 8: VTM (Forward and Reverse)
To test VTM, the Quadrac must be connected the same as
when testing VBO, IBO, and ΔVBO.
PER
VTM
H
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500
mV
DIV
PER
To connect the Quadrac:
S
T
E
P
IPK
1. Connect MT1 to Emitter Terminal (E).
()k
DIV
9m
PER
DIV
2. Connect MT2 to Collector Terminal (C).
3. Connect Trigger Terminal to MT2 Terminal through a
10 Ω resistor.
Figure AN1006.20
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
VTM (Forward) = 1.1 V at IPK = 5.6 A
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
Procedure 10: VTM(Reverse)
PER
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To measure the VTM (Reverse) parameter:
DIV
1. Set Polarity to (-).
PER
2. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
H
O
R
I
Z
S
T
E
P
IH
()k
DIV
9m
PER
DIV
Procedure 11: IH(Forward and Reverse)
1. Set Power Dissipation to 50 W.
Figure AN1006.21
IH (Forward) = 18 mA
Procedure 13: IH(Reverse)
To measure the IH (Reverse) parameter:
2. Set Max Peak Volts to 75 V. (80 V on 370)
1. Set Polarity to (-).
3. Set Mode to DC.
2. Continue testing per Procedure 12 for measuring
IH (Reverse).
4. Set )PSJ[POUBM knob to 5 V/DIV.
5. Set Vertical knob to approximately 10% of the
maximum IH specified.
Note: Due to large variations of holding current values,
the scale may have to be adjusted to observe holding
current.
6. Set Terminal Selector to Emitter Grounded-Open
Base.
SIDACs
The SIDAC is a bidirectional voltage-triggered switch. Upon
application of a voltage exceeding the SIDAC breakover
voltage point, the SIDAC switches on through a negative
resistance region (similar to a DIAC) to a low on-state
voltage. Conduction continues until current is interrupted
or drops below minimum required holding current.
Procedure 12: IH(Forward)
To connect the SIDAC:
To measure the IH (Forward) parameter:
1. Connect MT1 to the Emitter Terminal (E).
1. Set Polarity to (+).
2. Connect MT2 to the Collector Terminal (C).
2. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
To begin testing, perform the following procedures.
3. Increase Variable Collector Supply Voltage to
maximum position (100).
Note: Depending on the vertical scale being used, the
dot may disappear completely from the screen.
4. Decrease Variable Collector Supply Voltage to the
point where the line on the CRT changes to a dot. The
position of the beginning point of the line, just before
the line changes to a dot, represents the IH value.
(Figure AN1006.21)
V
PER
4. Measure VTM(Reverse) the same as in Procedure 8. (Read
measurements from upper right corner of screen).
To measure the IH (Forward and Reverse) parameter:
5
DIV
3. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak).
For these steps, it is again necessary to connect the
Trigger to MT2 through a 10 Ω resistor. The other
connections remain the same.
5
mA
Procedure 1: (+) VDRM, (+)IDRM, (-)VDRM, (-)IDRM
Note: The (+) and (-) symbols are used to designate the
polarity of MT2 with reference to MT1.
To measure the (+)VDRM, (+)IDRM, (-)VDRM, and (-)IDRM
parameter:
1. Set Variable Collector Supply Voltage Range to
1500 Max Peak Volts.
2. Set )PSJ[POUBM knob to 50 V/DIV.
3. Set Mode to Leakage.
4. Set Polarity to (+).
5. Set Power Dissipation to 2.2 W. (2 W on 370)
6. Set Terminal Selector to Emitter Grounded-Open
Base.
7. Set Vertical knob to 50 μA/DIV. (Due to leakage mode,
the CRT readout will show 50 nA.)
Thyristor and Rectifier Testing Using Curve Tracers
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Procedure 2: (+)VDRM and (+)IDRM
Procedure 5: VBO
To measure the (+)VDRM and (+)IDRM parameter:
To measure the VBO parameter, increase Variable
Collector Supply Voltage until breakover occurs. (Figure
AN1006.23) The voltage at which current begins to flow
and voltage on CRT does not increase is the VBO value.
1. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
2. Increase Variable Collector Supply Voltage to the
rated VDRM of the device and observe the dot on the
CRT. Read across horizontally from the dot to the
vertical current scale. This measured value is the
leakage current. (Figure AN1006.22)
PER
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+IBO
VBO
PER
V
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DIV
H
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50
V
+VBO
IBO
DIV
S
T
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P
IDRM
Figure AN1006.22
()k
DIV
9m
PER
DIV
IDRM = 50 nA at VDRM = 90 V
Procedure 3: (-) VDRMand (-) IDRM
To measure the (-)VDRM and (-)IDRM parameter:
1. Set Polarity to (-).
2. Repeat Procedures 1 and 2. (Read measurements from
upper right corner of the screen).
Procedure 4: VBO and IBO
To measure the VBO and IBO parameter:
1. Set Variable Collector Supply Voltage Range to
1500 Max Peak Volts. (2000 V on 370)
2. Set )PSJ[POUBM knob to a sufficient scale to allow
viewing of trace at the required voltage level (50 V/DIV
for 95 V to 215 V VBO range devices and 100 V/DIVfor
devices having VBO ≥ 15 V).
H
O
R
I
Z
50
V
PER
S
T
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P
()k
DIV
9m
PER
DIV
PER
VDRM
PER
DIV
50
nA
PER
50
A
DIV
Figure AN1006.23
(+)VBO = 100 V; (-)VBO = 100 V; (±)IBO˜"
Procedure 6: IBO
To measure the IBO parameter, at the VBO point, measure
the amount of device current just before the device
reaches the breakover mode. The measured current at this
point is the IBO value.
Note: If IBO is less than 10 μA, the current cannot readily be
seen on the curve tracer.
Procedure 7: IH(Forward and Reverse)
To measure the IH (Forward and Reverse) parameter:
1. Set Variable Collector Supply Voltage Range to
1500 Max Peak Volts (400 V on 577; 2000 V on 370).
2. Set )PSJ[POUBM knob to a sufficient scale to allow
WJFXJOHPGUSBDFBUUIFSFRVJSFEWPMUBHFMFWFM7%*7
for devices with VBO range from 95 V to 215 V and 100
7%*7GPSEFWJDFTIBWJOH7BO ≥ 215 V).
3. Set Vertical knob to 20% of maximum holding current
specified.
3. Set Vertical knob to 50 A/DIV.
4. Set Polarity to AC.
4. Set Polarity to AC.
5. Set Mode to Norm.
5. Set Mode to Norm.
6. Set Power Dissipation to 220 W (100 W on 577).
6. Set Power Dissipation to 10 W.
7. Set Terminal Selector to Emitter Grounded-Open
Base.
7. Set Terminal Selector to Emitter Grounded-Open
Base.
8. Set Left-Right Terminal Jack Selector to correspond
with location of test fixture.
8. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
WARNING: Limit test time to 15 seconds maximum.
9. Increase Variable Collector Supply Voltage until
device breaks over and turns on. (Figure AN1006.24)
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
PER
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20
mA
3. To measure VTM, follow along horizontal scale to the
point where the trace crosses the IT(peak) value. This
horizontal distance is the VTM value. (Figure AN1006.25)
DIV
PER
H
O
R
I
Z
IH
50
V
PER
V
E
R
T
DIV
500
mA
DIV
IH
PER
S
T
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P
PER
H
O
R
I
Z
()k
DIV
9m
PER
DIV
Figure AN1006.24
DIV
VTM
IH = 48 mA in both forward and reverse
directions
IH is the vertical distance between the center horizontal
axis and the beginning of the line located on center vertical
axis.
500
mV
PER
S
T
E
P
IPK
Figure AN1006.25
()k
DIV
9m
PER
DIV
VTM (Forward) = 950 mV at IPK = 1.4 A
Procedure10: VTM(Reverse)
Procedure 8: VTM(Forward and Reverse)
To measure the VTM (Forward and Reverse) parameter:
To measure the VTM (Reverse) parameter:
Set Polarity to (-).
1. Set Variable Collector Supply Voltage Range to 350
Max Peak Volts. (400 V on 370)
Repeat Procedure 8 to measure VTM(Reverse).
2. Set )PSJ[POUBM knob to 0.5 V/DIV.
DIACs
3. Set Vertical knob to 0.5 A/DIV.
4. Set Polarity to (+).
5. Set Mode to Norm.
DIACs are voltage breakdown switches used to trigger-on
Triacs and non-sensitive SCRs in phase control circuits.
6. Set Power Dissipation to 220 W (100 W on 577).
Note: DIACs are bi-directional devices and can be
connected in either direction.
7. Set Terminal Selector to Emitter Grounded-Open
Base.
To connect the DIAC:
Before continuing with testing, note the following:
Connect one side of the DIAC to the Collector Terminal (C).
t ",FMWJOUFTUmYUVSFJTSFRVJSFEGPSUIJTUFTU*GB
Kelvin fixture is not used, an error in measurement
of VTM will result due to voltage drop in fixture. If a
Kelvin fixture is not available, Figure AN1006.3 shows
necessary information to wire a test fixture with Kelvin
Connections.
Connect other side of the DIAC to the Emitter Terminal (E).
To continue testing, perform the following procedures.
Procedure 9:VTM(Forward)
To measure the VTM (Forward) parameter:
1. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
2. Increase Variable Collector Supply Voltage until
current reaches rated IT(peak), which is 1.4 times the IT(RMS)
rating of the SIDAC.
Note: Model 370 current is limited. Set to 400 mA.
Check for 1.1 V MAX.
WARNING: Limit test time to 15 seconds.
Thyristor and Rectifier Testing Using Curve Tracers
To begin testing, perform the following procedures.
Procedure 1: Curve Tracer Setup
To set the curve tracer and begin testing:
1
Set Variable Collector Supply Voltage Range to 75
Max Peak Volts. (80 V on 370)
2. Set )PSJ[POUBM knob to sufficient scale to allow viewing
of trace at the required voltage level (10 V to 20 V/DIV
depending on device being tested).
3. Set Vertical knob to 50 μA/DIV.
4. Set Polarity to AC.
5. Set Mode to Norm.
6. Set Power Dissipation to 0.5 W. (0.4 W on 370)
7. Set Terminal Selector to Emitter Grounded-Open
Base.
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Procedure 2: VBO
Model 370 Curve Tracer Procedure Notes
To measure the VBO parameter:
1. Set Left-Right Terminal Jack Selector to correspond
with the location of the test fixture.
2. Set Variable Collector Supply Voltage to 55 V (65 V
for 370) and apply voltage to device under test (D.U.T.),
using Left-Right-Selector Switch. The peak voltage
at which current begins to flow is the VBO value. (Figure
AN1006.26)
PER
V
E
R
T
50
A
Because the curve tracer procedures in this application
note are written for the Tektronix model 576 curve tracer,
certain settings must be adjusted when using model
370. Variable Collector Supply Voltage Range and Power
Dissipation controls have different scales than model 576.
The following table shows the guidelines for setting Power
Dissipation when using model 370. (Figure AN1006.27)
Model 576
Model 370
If power dissipation is 0.1 W,
set at 0.08 W.
If power dissipation is 0.5 W,
set at 0.4 W.
If power dissipation is 2.2 W,
set at 2 W.
If power dissipation is 10 W,
set at 10 W.
If power dissipation is 50 W,
set at 50 W.
If power dissipation is 220 W,
set at 220 W.
DIV
+IBO
PER
H
O
R
I
Z
10
V
DIV
PER
IBO
VBO
+VBO
S
T
E
P
()k
DIV
9m
PER
DIV
Although the maximum power setting on the model 370
curve tracer is 200 W, the maximum collector voltage
available is only 400 V at 220 W. The following table shows
the guidelines for adapting Collector Supply Voltage Range
settings for model 370 curve tracer procedures:
Model 576
Figure AN1006.26
Procedure 3:
(+)VBO = 35 V; (-)VBO = 36 V; (±)IBO˜"
IBO˜"BOE$BOOPU#F3FBE&BTJMZ
IBO
To measure the IBO parameter, at the VBO point, measure
the amount of device current just before the device
reaches the breakover mode. The measured current at this
point is the IBO value.
Note: If IBO is less than 10 μA, the current cannot readily be
seen on the curve tracer.
Procedure 4: ΔVBO(Voltage Breakover Symmetry)
To measure the ΔVBO (Voltage Breakover Symmetry) parameter:
1. Measure positive and negative values of VBO as shown
in Figure AN1006.26.
Model 370
If voltage range is 15 V
set at 16 V.
If voltage range is 75 V
set at 80 V.
If voltage range is 350 V
set at 400 V.
If voltage range is 1500 V
set at 2000 V
The following table shows the guidelines for adapting
terminal selector knob settings for model 370 curve tracer
procedures:
Model 576
Model 370
If Step generator (base) is emitter
grounded
then Base Step generator
is emitter common.
If Emitter grounded is open base
then Base open is emitter
common.
2. Subtract the absolute value of VBO(-) from VBO(+).
The absolute value of the result is:
ΔVBO = [ I +VBO I - I -VBO I ]
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006
Teccor® brand Thyristors
AN1006
HORIZONTAL
VOLTAGE CONTROL
PROGRAMMABLE
CURVE TRACER
DISPLAY
INTENSITY
SETUP
MEMORY
Note: All Voltage
Settings Will Be
Referenced to
"Collector"
STEP GENERATOR
HORIZONTAL
VOLTS/DIV
VERTICAL
CURRENT/DIV
VERT/DIV
CURSOR
POLARITY
STEP/OFFSET
AMPLITUDE
COLLECTOR
HORZ/DIV
CURSOR
CRT
STEP/OFFSET
POLARITY
STEP/OFFSET
AMPLITUDE
(AMPS/VOLTS)
PER STEP
OFFSET
OFFSET
OFFSET
OR gm/DIV
CURSOR
POSITION
AUX SUPPLY
GPIB
PLOTTER
MEASUREMENT
STEP
FAMILY
AUX SIPPLY
COLLECTOR SUPPLY
VARIABLE
COLLECTOR
SUPPLY VOLTAGE
RANGE
TERMINAL
JACKS
CONFIGURATION
COLLECTOR SUPPLY
MAX PEAK
VOLTS
C
C
POLARITY
VARIABLE
GATE/TRIGGER
B
LEFT
B
SENSE
B
E
E
BOTH
B
SENSE
VARIABLE
COLLECTOR
SUPPLY
VOLTAGE
E
SENSE
E
SENSE
RIGHT
MAX PEAK
POWER
(POWER DISSIPATION)
C
SENSE
C
SENSE
MT2/ANODE
MAX PEAK
POWER
WATTS
POWER
LEFT-RIGHT SELECTOR
FOR TERMINAL JACKS
Figure AN1006.27
MT1/CATHODE
KELVIN TERMINALS
USED WHEN
MEASURING V TM OR V FM
TERMINAL
SELECTOR
Tektronix Model 370 Curve Tracer
Model 577 Curve Tracer Procedure Notes
Because the curve tracer procedures in this application note are written for the Tektronix model 576 curve tracer, certain
settings must be adjusted when using model 577. Model 576 curve tracer has separate controls for polarity (AC,+,-) and
mode (Norm, DC, Leakage), whereas Model 577 has only a polarity control. The following table shows the guidelines for
setting Collector Supply Polarity when using model 577. (Figure AN1006.28)
Model 576
Model 577
If using Leakage mode along with polarity setting of +(NPN) and
-(PNP),[vertical scale divided by 1,000],
set Collector Supply Polarity to either +DC or -DC, depending on
polarity setting specified in the procedure. The vertical scale is read
directly from the scale on the control knob.
If using DC mode along with either +(NPN) or -(PNP) polarity,
set Collector Supply Polarity to either +DC or -DC depending on
polarity specified.
If using Norm mode along with either +(NPN) or -(PNP) polarity,
set Collector Supply Polarity to either +(NPN) or -(PNP) per specified
procedure.
If using Norm mode with AC polarity,
0OFEJGGFSFODFCFUXFFONPEFMTBOEJTUIF4UFQ
Offset Polarity setting. The polarity is inverted when
the button is depressed on the Model 576 curve tracer.
5IF.PEFMJTPQQPTJUF‰UIF4UFQ0GGTFU1PMBSJUZJT
“inverted” when the button is extended and “Normal”
Thyristor and Rectifier Testing Using Curve Tracers
set Collector Supply Polarity to AC.
XIFOUIFCVUUPOJTEFQSFTTFE5IF4UFQ0GGTFU1PMBSJUZ
is used only when measuring IGT and VGT of Triacs and
Quadracs in Quadrants l through lV.
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Teccor® brand Thyristors
Also, the Variable Collector Supply Voltage Range and
Power Dissipation controls have different scales than
model 576. The following table shows the guidelines for
setting Power Dissipation when using model 577.
Model 576
Although the maximum power setting on model 576 curve
tracer is 220 W (compared to 100 W for model 577), the
maximum collector current available is approximately the
same. This is due to the minimum voltage range on model
577 curve tracer being 6.5 V compared to 15 V for model
576. The following table shows the guidelines for adapting
Collector Voltage Supply Range settings for model 577
curve tracer procedures:
Model 577
If power dissipation is 0.1 W,
set at 0.15 W.
If power dissipation is 0.5 W,
set at 0.6 W.
If power dissipation is 2.2 W,
set at 2.3 W.
If power dissipation is 10 W,
set at 9 W.
If power dissipation is 50 W,
set at 30 W.
If power dissipation is 220 W,
set at 100 W.
Model 576
Model 577
If voltage range is 15 V
set at either 6.5 V or 25 V, depending
on parameter being tested. Set at
6.5 V when measuring VTM (to allow
maximum collector current) and set
at 25 V when measuring IGT and VGT.
If voltage range is 75 V
set at 100 V.
If voltage range is 1500 V,
set at 1600 V.
BRIGHTNESS
STORE
INTENSITY
CRT
Avoid
extremely
bright display
FOCUS
Adjust for
best focus
BEAM
FINDER
VARIABLE COLLECTOR
SUPPLY VOLTAGE RANGE
VARIABLE COLLECTOR
SUPPLY VOLTAGE
POWER
STEP
FAMILY
VARIABLE
COLLECTOR%
STEP
GENERATOR
SECTION
STEP/OFFSET
AMPLIFIER
MAX PEAK
VOLTS
NUMBER OF STEPS
MAX PEAK POWER
(POWER DISSIPATION)
OFFSET
MULTI
Watch high power
settings. Can damage
device under test
STEP/OFFSET
POLARITY
POLARITY
COLLECTOR SUPPLY
POLARITY
POSITION
DISPLAY
Indicates
Collector
Supply
Disabled
HORIZONTAL
VOLTAGE CONTROL
Note: All Voltage
Settings Will Be
Referenced to
"Collector"
STEP
RATE
POSITION
COLLECTOR SUPPLY
Terminal Selector
TERMINAL
JACKS
MT2/ANODE
GATE/TRIGGER
MT1/CATHODE
C
C
SENSE
C
B
E
C
SENSE
B
E
SENSE
E
Indicates Dangerous
Voltages on Test
jacks
E
SENSE
VERTICAL
(off)
LEFT-RIGHT
SELECTOR FOR
TERMINAL JACKS
LEFT
RIGHT
KELVIN TERMINALS
USED WHEN MEASURING VTM OR VFM
VARIABLE
VOLTAGE
LOOPING
COMPENSATION
Figure AN1006.28
STEP GEN
OUTPUT
VARIABLE
OUTPUT
VERTICAL CURRENT
SUPPLY
GROUND
EXT BASE
OR EMIT
INPUT
Tektronix Model 577 Curve Tracer
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to http://www.littelfuse.com for current information.
Thyristor and Rectifier Testing Using Curve Tracers
AN1006
AN1006