11-20
Limit Testing
Limit test programming example
Diode breakdown voltage test is an example that readily lends itself to pass/fail analysis.
This test veri
fi
es the reverse and often the forward voltage at which the device begins to show a
large deviation in current for a small deviation in voltage. The test is performed by sourcing a
speci
fi
ed current level and then measuring the resulting voltage drop. The voltage drop is then
compared with one set of limits to determine if the diode passes, or fails and should be dis-
carded. Voltage measurements for failing diodes are also compared against a more restricted
range of limits to determine if they should be routed to QA (Quality Assurance) for further
analysis.
Test parameters for this test include:
•
Source Function: current
•
Sense Function: voltage
•
Source Current: 100mA
•
Source Delay: 100ms
•
Limit 2 Upper Value: 0.85V
•
Limit 2 Lower Value: 0.75V
•
Limit 3 Upper Value: 0.82V
•
Limit 3 Lower Value: 0.78V
Figure 11-11 demonstrates graphically how parts are sorted. Diodes with a voltage between
0.78V and 0.82V are considered good and will pass the limits test. Diodes that test with a
slightly wider voltage range are routed to QA for analysis, while those with the largest voltage
tolerance will be discarded.
Command*
Description*
:SOURce2:BSIZe <n>
Set Digital I/O port bit size (n = 3 or 4).
:SOURce2:TTL <NRf> | <NDN>
Set I/O port bit pattern (NRf | NDN = pattern).
:SOURce2:TTL:ACTual?
Query bit pattern on digital output port.
:SOURce2:TTL4:MODE <name>
Set Digital I/O line 4 mode (name = EOTest or
BUSY).
:SOURce2:TTL4:BSTate <state>
Set BUSY and EOT polarity (HI or LO).
:SOURce2:CLEar
Clear digital output lines.
:SOURce2:CLEar:AUTO <state>
Enable/disable I/O port auto clear (state = ON or
OFF).
:SOURce2:CLEar:AUTO:DELay <n>
Set auto-clear delay (n = delay).
*LIMitX = LIMit2, LIMit3, LIMit5 through LIMit12.
Table 11-1 (cont.)
Limit commands
Bad Diode,
Discard
Bad Diode,
to QA
Good
Diode
Bad Diode,
to QA
Bad Diode,
Discard
Low Limit 2
(0.75V)
Low Limit 3
(0.78V)
Upper Limit 3
(0.82V)
Upper Limit 2
(0.85V)
Figure 11-11
Diode pass/fail limits
Summary of Contents for 6430
Page 26: ......
Page 32: ......
Page 78: ...2 14 Connections ...
Page 98: ...3 20 Basic Source Measure Operation ...
Page 138: ...5 30 Source Measure Concepts ...
Page 156: ...6 18 Range Digits Speed and Filters ...
Page 168: ...7 12 Relative and Math ...
Page 176: ...8 8 Data Store ...
Page 202: ...9 26 Sweep Operation ...
Page 248: ...11 22 Limit Testing ...
Page 310: ...16 6 SCPI Signal Oriented Measurement Commands ...
Page 418: ...17 108 SCPI Command Reference ...
Page 450: ...18 32 Performance Verification ...
Page 477: ...A Specifications ...
Page 489: ...B StatusandErrorMessages ...
Page 498: ...B 10 Status and Error Messages ...
Page 499: ...C DataFlow ...
Page 503: ...D IEEE 488BusOverview ...
Page 518: ...D 16 IEEE 488 Bus Overview ...
Page 519: ...E IEEE 488andSCPI ConformanceInformation ...
Page 523: ...F MeasurementConsiderations ...
Page 539: ...G GPIB488 1Protocol ...
Page 557: ......