CN103728037A - Junction temperature monitoring circuit system for high-power LED reliability test - Google Patents
Junction temperature monitoring circuit system for high-power LED reliability test Download PDFInfo
- Publication number
- CN103728037A CN103728037A CN201410006434.2A CN201410006434A CN103728037A CN 103728037 A CN103728037 A CN 103728037A CN 201410006434 A CN201410006434 A CN 201410006434A CN 103728037 A CN103728037 A CN 103728037A
- Authority
- CN
- China
- Prior art keywords
- led
- test
- output
- circuit
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Led Devices (AREA)
Abstract
The invention discloses a junction temperature monitoring circuit and method for a high-power LED reliability test. The circuit comprises a fast switching module, a delay sampling module, a self-calibration module, a constant current source testing module and a constant current source driving module, wherein the fast switching module is used for fast switching off the constant current source driving module, the delay sampling module is used for acquiring forward voltage drops at two ends of an LED and produced by the constant current source testing module, the self-calibration module is used for comparing forward voltages of the LED to be tested and a reference LED at different temperatures, eliminating physical property change of the LED to be tested due to testing current through a self-calibration link and obtaining the junction temperature of the LED to be tested in a reliability test environment. The circuit can monitor the stable junction temperature change tendency of the LED in work in real time, and a scientific evaluation basis is provided for description and evaluation of LED package module thermal performance in the reliability test.
Description
Technical field
The invention belongs to optoelectronic information Detection & Controling field, be specifically related to a kind of junction temperature observation circuit system of great power LED fail-test.
Background technology
Great power LED is the blue-light LED chip more than 1W by rated power, consists of the basic device of semiconductor lighting encapsulation.At present, the reliability of great power LED is its bottleneck in field of semiconductor illumination development of restriction, become distinct issues with light decay and closely bound up junction temperature of life-span, LED luminous flux is as the important parameter of evaluating reliability, be not only the function of chip size and chip technology, or the function of a junction temperature.In prior art, also the fluctuation of great power LED junction temperature in fail-test is not carried out technology and the method for on-line monitoring.
The variations injunction temperature of existing LED junction temperature proving installation in cannot Real-Time Monitoring LED fail-test, the technology of an on-line monitoring junction temperature of development is the important means of research semiconductor lighting reliability.
Summary of the invention
For the problems referred to above, the invention provides a kind of junction temperature observation circuit system that can stable state variations injunction temperature, the efficient Quick Measurement of LED junction temperature and the great power LED fail-test of performance characterization of Real-Time Monitoring LED in fail-test.
For achieving the above object, the junction temperature observation circuit of great power LED fail-test of the present invention, comprise and drive constant current source module (500), test constant current source module (400), quick handover module (100), described time delay sampling module (200) and self calibration module (300), wherein
Described driving constant current source module is electrically connected LED to be measured, and described LED to be measured is heated;
The described LED to be measured of described test constant-current source circuit electrical connection, provides described LED to be measured to test required electric current;
Described quick handover module, acts on light emitting diode to be measured for the output current of controlling described driving constant flow module in the heating cycle of described LED to be measured, test period is bypassed to ground;
Described time delay sampling module, connect crystal oscillator (201) and supply standard clock signal by described crystal oscillator, produce gating pulse sequential, the forward voltage of the LED described to be measured (10) that gathers described test constant current source module output based on described gating pulse sequential under the described measuring current cycle;
Described self-calibration module electrical connection the 3rd DVM (301), described self-calibration module is by LED more to be measured with reference to LED, eliminating the physical property that LED to be measured causes by electric current changes, the junction temperature of on-line monitoring LED to be measured under different reliability environments, obtain the change in voltage that described LED to be measured is caused by temperature effect, and described Voltage-output to described the 3rd DVM is shown;
Described system also comprises the first sample resistance (R for testing constant current source module output current described in sampling monitoring
ts) and the first DVM (401), for driving the second sample resistance (R of constant current source module output current described in sampling monitoring
ds) and the second DVM (501).
Further, described delay sampling circuit comprises the first counter and the second counter that are connected in series, the clock end of described the first counter and the second counter is connected crystal oscillator, described crystal oscillator clock signal, described the first counter (U201) is connected respectively with two input ends of the first not gate (U203) and is connected with the output terminal of the second counter (U202), form a frequency dividing circuit, the output terminal of described the first Sheffer stroke gate connects an input end of the second Sheffer stroke gate, described frequency dividing circuit output sampling pulse is to described the second Sheffer stroke gate (U204), the moved end of single-pole double-throw switch (SPDT) (S201) connects reference voltage+12V, a motionless terminal is for demarcating end, another motionless terminal is test lead, described demarcation holds unsettled connection to be high-impedance state, described test lead connects two input ends of described the second Sheffer stroke gate, the first filter resistance (R201) series connection the first filtering diode (D201), the test lead that the second filter resistance (R202) is connected respectively described single-pole double-throw switch (SPDT) with described the first filter capacitor is to ground, for filtering clutter and condition prompting.
The 3rd resistance (R203) is connected with the 3rd Sheffer stroke gate (U204) output terminal with the charging and discharging circuit that the first electric capacity (C203) forms, what the 4th Sheffer stroke gate (U205) and the first rejection gate (U207), consist of exports time delay sampled signal with exclusive disjunction circuit, the exclusive disjunction circuit output drive pulse signal consisting of the second rejection gate (U206) and the 3rd rejection gate (U208); The P end of described LED to be measured is connected to the in-phase end of the voltage follower consisting of the first amplifier (A201), the output of described the first amplifier (A201) connects by the 4th resistance (R204), the analog sampling circuit that analog switch A and the second electric capacity (C204) form, the control end of described analog switch A connects described time delay sampling pulse signal, the output of described analog switch A is connected to the in-phase input end of the voltage follower consisting of the second amplifier (A202), output sampled signal;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, the 3rd Sheffer stroke gate (U204) is at one end under low level input, be output as high level, described time delay sampling pulse and described drive pulse signal are high level, analog switch A conducting, the forward voltage that sampled signal is LED to be measured;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, the 3rd described Sheffer stroke gate U204 is output as the sampling pulse that described dutycycle is 1%, in described time delay sampling pulse signal high level period, analog switch A conducting, export the forward voltage of light emitting diode to be measured, in described time delay sampling pulse signal low-level period, analog switch A cut-off, sampled signal enters hold mode.
Further, described fast switch circuit comprises optocoupler, the first metal-oxide-semiconductor that described optocoupler connects, the input end of described optocoupler and output terminal are serially connected with respectively the first switch resistance and second switch resistance, described optocoupler is connected with the grid of the first metal-oxide-semiconductor, described fast switch circuit unit also comprises the first diode and the second diode, described the first diode is connected to being connected on branch road of described test constant current source and described LED to be measured, described the second diode is connected to being connected on branch road of described driving constant current source and described LED to be measured, the described second diode P utmost point connects the source electrode of described the first metal-oxide-semiconductor by the first sampling resistor, described optocoupler is connected with the drive pulse signal output terminal of described delay sampling circuit,
When described single-pole double-throw switch (SPDT) S201 is placed in, demarcate when end, control described driving signal and be output as low level, described optocoupler conducting output high level, the first metal-oxide-semiconductor conducting described in described optocoupler control, the output current of described driving constant-current source circuit is bypassed;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, controlling described driving signal is pulse signal, between pulse signal high period, described optocoupler is high-impedance state, described the first metal-oxide-semiconductor is in cut-off state, and described driving constant-current circuit and described test constant-current circuit output to described LED to be measured jointly, and it is heated;
Between pulse signal low period, described optocoupler and the equal conducting of a described MOS, drive current is bypassed, and makes the forward voltage that only has described test constant current to cause on described LED to be measured.
Further, described self-calibration module comprises with reference to LED, stabilized voltage supply (U301), three operational amplifier the 3rd operational amplifiers (A301), four-operational amplifier (A302), the 5th operational amplifier (A303), eight test resistance, the first test resistance, the second test resistance, the 3rd test resistance, the 4th test resistance, the 5th test resistance, the 6th test resistance, the 7th test resistance, the 8th test resistance (R301～R308).
Wherein, described test constant current source module is connected with the end of oppisite phase of the first operational amplifier (A301) by the first resistance (R301), the in-phase end of the 3rd described operational amplifier (A301) is by the second test resistance (R302) ground connection, described reference LED connects reversed-phase output and the output terminal of the 3rd described operational amplifier (A301), formation is with reference to LED negative circuit, and output is with reference to LED test voltage signal.The positive and negative reference voltage end of described stabilized voltage supply (U301) is connected to respectively slide rheostat two ends, the tap terminals of described slide rheostat Rg is connected to the in-phase input end of the voltage follower being comprised of described four-operational amplifier (A302), according to the change in resistance of described slide rheostat Rg, form zeroing circuit, output zeroing signal; Described sampled signal, with reference to LED test voltage signal, zeroing signal is by described electricity the 3rd test resistance, the 4th test resistance, the 5th test resistance coupling, by the 6th test resistance (R306) ground connection, and be input to the in-phase input end of the 5th operational amplifier (A303), the output terminal of described the 5th operational amplifier (A303) is by described the 7th test resistance, the 8th test resistance ground connection, and by the Voltage Feedback at described the 8th test resistance two ends to the inverting input of described the 5th operational amplifier, form in-phase proportion amplifying circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, sampled signal is the measuring current of described test constant flow module output at the forward voltage of light emitting diode to be measured two ends generation, described reference LED test voltage signal is for test constant current is in the negative value of the forward voltage producing with reference to LED two ends, described zeroing circuit, by described Rg output small voltage, regulates the zero point of whole circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in test lead, sampled signal is captured in the forward voltage of light emitting diode to be measured described under measuring current in the different temperatures period, described reference LED is output as the forward voltage that the measuring current under normal temperature causes, zeroing signal keeps stable in this process, the in-phase proportion amplifying circuit output variations injunction temperature signal consisting of described (A303).
For achieving the above object, the junction temperature monitoring method of great power LED fail-test of the present invention, comprises the junction temperature observation circuit of above-mentioned great power LED fail-test, and described method comprises:
Step S1, use single-pole double-throw switch (SPDT) (S201), controlling described the first rejection gate (U207) and the second rejection gate (U208) output terminal is high level, makes the forward output voltage under described analog switch A continuous acquisition measuring current;
Step S2, carries out initialization by the zeroing circuit of described four-operational amplifier (A302) and described (U301) to on-line monitoring circuit;
Step S3, given described reference LED and the difference of LED environment temperature to be measured, the forward voltage of measuring under this difference changes, and junction temperature transduction factor is demarcated;
Step S4, reliability junction temperature on-line testing link is used single-pole double-throw switch (SPDT) (S201), controls LED forward voltage signal maintenance under described analog switch A quick sampling measuring current;
Step S5, calculates the variations injunction temperature value of LED to be measured under fail-test environment according to the junction temperature transduction factor of demarcating, and adds test ambient temperature, obtains final LED junction temperature value to be measured.
1, junction temperature on-line monitoring circuit and the method for a kind of large-power light-emitting diodes fail-test provided by the invention, can cooperatively interact with current LED fail-test case, the directly fluctuation of Real-Time Monitoring junction temperature in LED fail-test, substitutes the traditional off-line test method that sample detects separately of originally taking out from reliability environment.
2, the present invention eliminates the impact of physical parameter in LED on-line testing process to be measured own by a reference LED of the same type, has improved junction temperature test in prior art and has directly measured LED both end voltage situation of change to be measured.
3, the charge-discharge circuit that the R203 that the present invention adopts and C203 form provides adjustable time delay sampled signal in certain limit, can meet the diversity of test sample, improves the dirigibility of junction temperature observation circuit control.
Accompanying drawing explanation
Fig. 1 is the structural principle block diagram of the junction temperature on-line monitoring circuit of large-power light-emitting diodes fail-test provided by the invention;
Fig. 2 is the fundamental diagram of quick handover module provided by the invention;
Fig. 3 is the fundamental diagram of time delay sampling module provided by the invention;
Fig. 4 is the fundamental diagram of self-calibration module provided by the invention;
Fig. 5 is the junction temperature on-line monitoring method process flow diagram of a kind of large-power light-emitting diodes fail-test provided by the invention.
Embodiment
Below in conjunction with Figure of description, the present invention will be further described.
The concrete structure theory diagram of observation circuit provided by the invention as shown in Figure 1, as shown in Figure 1, this observation circuit comprises quick handover module 100, time delay sampling module 200, self-calibration module 300, test constant current source module 400, drive constant current source module 500, handover module cuts off driving constant current source module by sampling time sequence fast, time delay sampling module gathers the forward voltage of LED to be measured at test constant current source module operation time, self-calibration module adopts with reference to the anti-phase of LED amplifies and obtains the magnitude of voltage corresponding with current junction temperature with zeroing circuit in proportion, the DVM of output converses variations injunction temperature value, add fail-test environment temperature, obtain the LED junction temperature of the on-line testing under fail-test.
Fig. 2 is the fundamental diagram of a kind of quick handover module provided by the invention, test constant current source and driving constant current source are by diode D1 and D2 coupling, when driving signal to be high level, the MOSFET of a N raceway groove effective come bypass drive constant current, now D2 is reverse-biased, and LED to be measured only has measuring current to pass through.
Fig. 3 is the fundamental diagram of a kind of time delay sampling module provided by the invention, as shown in Figure 3, clock signal is after timer 1 and timer 2 frequency divisions, by the certain pulse-period signal of Sheffer stroke gate U203 output duty cycle, single-pole double-throw switch (SPDT) S201 is that whole test circuit is selected duty by controlling the incoming level of Sheffer stroke gate U204.When demarcating link, U204 is output as height, and U207 output and U208 output are high level, and analog switch A is all the time in conducting state; When in test link, U204 exports pulse-period signal, drive pulse signal control drive current outputs to LED to be measured or switches in analog, sampling time delayed signal lags behind drive pulse signal, the break-make of control simulation switch, select the time point of time delay sampling in circuit, making to test constant current source, to be loaded into the voltage at LED to be measured two ends collected.
Fig. 4 is the fundamental diagram of a kind of self-calibration module provided by the invention, test constant current source is for providing the measuring current of formed objects with reference to LED, operational amplifier A 301 is anti-phase with reference to LED both end voltage, dividing potential drop on slide rheostat Rg is used for regulating the initial zero position of test circuit, output signal and the sampled signal of A301 and A302 are done additive operation by resistively couple, and operational amplifier A 303 is exported the variations injunction temperature signal of LED to be measured.
As shown in Fig. 1 to 5, the junction temperature observation circuit of great power LED fail-test of the present invention, comprises and drives constant current source module 500, test constant current source module 400, quick handover module 100, described time delay sampling module 200 and self calibration module 300, wherein,
Described driving constant current source module is electrically connected LED to be measured, and described LED to be measured is heated;
The described LED to be measured of described test constant-current source circuit electrical connection, provides described LED to be measured to test required electric current;
Described quick handover module, acts on light emitting diode to be measured for the output current of controlling described driving constant flow module in the heating cycle of described LED to be measured, test period is bypassed to ground;
Described time delay sampling module, connect crystal oscillator 201 and supply standard clock signal by described crystal oscillator, produce gating pulse sequential, the forward voltage of the LED10 described to be measured that gathers described test constant current source module output based on described gating pulse sequential under the described measuring current cycle;
Described self-calibration module electrical connection the 3rd DVM 301, described self-calibration module is by LED more to be measured with reference to LED, eliminating the physical property that LED to be measured causes by electric current changes, the junction temperature of on-line monitoring LED to be measured under different reliability environments, obtain the change in voltage that described LED to be measured is caused by temperature effect, and described Voltage-output to described the 3rd DVM is shown;
Described system also comprises the first sample resistance R for testing constant current source module output current described in sampling monitoring
tsand first DVM 401, for driving the second sample resistance R of constant current source module output current described in sampling monitoring
dsand second DVM 501.
Further, described delay sampling circuit comprises the first counter and the second counter that are connected in series, the clock end of described the first counter and the second counter is connected crystal oscillator, described crystal oscillator clock signal, the output terminal of described the first counter U201 and the second counter U202 is connected respectively with two input ends of the first not gate U203 and is connected, form a frequency dividing circuit, the output terminal of described the first Sheffer stroke gate connects an input end of the second Sheffer stroke gate, described frequency dividing circuit output sampling pulse is to described the second Sheffer stroke gate U204, the moved end of single-pole double-throw switch (SPDT) (S201) connects reference voltage+12V, a motionless terminal is for demarcating end, another motionless terminal is test lead, described demarcation holds unsettled connection to be high-impedance state, described test lead connects two input ends of described the second Sheffer stroke gate, the first filter resistance (R201) series connection the first filtering diode (D201), the second filter resistance (R202) and described the first filter capacitor are connected respectively the test lead of described single-pole double-throw switch (SPDT), for filtering clutter and condition prompting,
The 3rd resistance (R203) is connected with the 3rd Sheffer stroke gate (U204) output terminal with the charging and discharging circuit that the first electric capacity (C203) forms, what the 4th Sheffer stroke gate (U205) and the first rejection gate (U207), consist of exports time delay sampled signal with exclusive disjunction circuit, the exclusive disjunction circuit output drive pulse signal consisting of the second rejection gate (U206) and the 3rd rejection gate (U208); The P end of described LED to be measured is connected to the in-phase end of the voltage follower consisting of the first amplifier (A201), the output of described the first amplifier (A201) connects by the 4th resistance (R204), the analog sampling circuit that analog switch A and the second electric capacity (C204) form, the control end of described analog switch A connects described time delay sampling pulse signal, the output of described analog switch A is connected to the in-phase input end of the voltage follower consisting of the second amplifier (A202), output sampled signal;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, the 3rd Sheffer stroke gate (U204) is at one end under low level input, be output as high level, described time delay sampling pulse and described drive pulse signal are high level, analog switch A conducting, the forward voltage that sampled signal is LED to be measured;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, the 3rd described Sheffer stroke gate U204 is output as the sampling pulse that described dutycycle is 1%, in described time delay sampling pulse signal high level period, analog switch A conducting, export the forward voltage of light emitting diode to be measured, in described time delay sampling pulse signal low-level period, analog switch A cut-off, sampled signal enters hold mode.
Further, described fast switch circuit comprises optocoupler, the first metal-oxide-semiconductor that described optocoupler connects, the input end of described optocoupler and output terminal are serially connected with respectively the first switch resistance and second switch resistance, described optocoupler is connected with the grid of the first metal-oxide-semiconductor, described fast switch circuit unit also comprises the first diode and the second diode, described the first diode is connected to being connected on branch road of described test constant current source and described LED to be measured, described the second diode is connected to being connected on branch road of described driving constant current source and described LED to be measured, the described second diode P utmost point connects the source electrode of described the first metal-oxide-semiconductor by the first sampling resistor, described optocoupler is connected with the drive pulse signal output terminal of described delay sampling circuit,
When described single-pole double-throw switch (SPDT) S201 is placed in, demarcate when end, control described driving signal and be output as low level, described optocoupler conducting output high level, the first metal-oxide-semiconductor conducting described in described optocoupler control, the output current of described driving constant-current source circuit is bypassed;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, controlling described driving signal is pulse signal, between pulse signal high period, described optocoupler is high-impedance state, described the first metal-oxide-semiconductor is in cut-off state, and described driving constant-current circuit and described test constant-current circuit output to described LED to be measured jointly, and it is heated;
Between pulse signal low period, described optocoupler and the equal conducting of a described MOS, drive current is bypassed, and makes the forward voltage that only has described test constant current to cause on described LED to be measured.
Further, described self-calibration module comprises with reference to LED, stabilized voltage supply (U301), three operational amplifier the 3rd operational amplifiers (A301), four-operational amplifier (A302), the 5th operational amplifier (A303), eight test resistance, the first test resistance, the second test resistance, the 3rd test resistance, the 4th test resistance, the 5th test resistance, the 6th test resistance, the 7th test resistance, the 8th test resistance (R301～R308).
Wherein, described test constant current source module is connected with the end of oppisite phase of the first operational amplifier (A301) by the first resistance (R301), the in-phase end of the 3rd described operational amplifier (A301) is by the second test resistance (R302) ground connection, described reference LED connects reversed-phase output and the output terminal of the 3rd described operational amplifier (A301), formation is with reference to LED negative circuit, and output is with reference to LED test voltage signal.The positive and negative reference voltage end of described stabilized voltage supply (U301) is connected to respectively slide rheostat two ends, the tap terminals of described slide rheostat Rg is connected to the in-phase input end of the voltage follower being comprised of described four-operational amplifier (A302), according to the change in resistance of described slide rheostat Rg, form zeroing circuit, output zeroing signal; Described sampled signal, with reference to LED test voltage signal, zeroing signal is by described electricity the 3rd test resistance, the 4th test resistance, the 5th test resistance coupling, by the 6th test resistance (R306) ground connection, and be input to the in-phase input end of the 5th operational amplifier (A303), the output terminal of described the 5th operational amplifier (A303) is by described the 7th test resistance, the 8th test resistance ground connection, and by the Voltage Feedback at described the 8th test resistance two ends to the inverting input of described the 5th operational amplifier, form in-phase proportion amplifying circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, sampled signal is the measuring current of described test constant flow module output at the forward voltage of light emitting diode to be measured two ends generation, described reference LED test voltage signal is for test constant current is in the negative value of the forward voltage producing with reference to LED two ends, described zeroing circuit, by described Rg output small voltage, regulates the zero point of whole circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in test lead, sampled signal is captured in the forward voltage of light emitting diode to be measured described under measuring current in the different temperatures period, described reference LED is output as the forward voltage that the measuring current under normal temperature causes, zeroing signal keeps stable in this process, the in-phase proportion amplifying circuit output variations injunction temperature signal consisting of described (A303).
The junction temperature monitoring method of great power LED fail-test of the present invention, comprises the junction temperature observation circuit of above-mentioned great power LED fail-test, and described method comprises:
Step S1, use single-pole double-throw switch (SPDT) (S201), controlling described the first rejection gate (U207) and the second rejection gate (U208) output terminal is high level, makes the forward output voltage under described analog switch A continuous acquisition measuring current;
Step S2, carries out initialization by the zeroing circuit of described four-operational amplifier (A302) and described (U301) to on-line monitoring circuit;
Step S3, given described reference LED and the difference of LED environment temperature to be measured, the forward voltage of measuring under this difference changes, and junction temperature transduction factor is demarcated;
Step S4, reliability junction temperature on-line testing link is used single-pole double-throw switch (SPDT) (S201), controls LED forward voltage signal maintenance under described analog switch A quick sampling measuring current;
Step S5, calculates the variations injunction temperature value of LED to be measured under fail-test environment according to the junction temperature transduction factor of demarcating, and adds test ambient temperature, obtains final LED junction temperature value to be measured.
The junction temperature observation circuit of large-power light-emitting diodes fail-test of the present invention, described circuit comprises: drive constant current source module, test constant current source module, for sample resistance Rts and the DVM 1 of testing constant current source module output current described in sampling monitoring, for driving sample resistance Rds and the DVM 2 of constant current source module output current described in sampling monitoring, for driving the quick handover module of the output current of constant current source module described in bypass, the self calibration module of the time delay sampling module of described quick handover module electrical connection and the electrical connection of described time delay sampling module and for showing the DVM 3 of voltage and temperature signal, wherein said quick handover module is electrically connected described light emitting diode,
Described driving constant current source module,, heats described light emitting diode for described light emitting diode provides working direct current by described quick handover module;
Described test constant current source module, provides measuring current by described quick handover module for described light emitting diode, and exports the forward voltage under measuring current;
Described quick handover module, acts on light emitting diode to be measured for the output current of controlling described driving constant flow module in the heating cycle of described light emitting diode, test period is bypassed to ground;
Described time delay sampling module, by crystal oscillator, supply standard clock signal, adopt signal lag processing module to produce the gating pulse sequential of circuit of the present invention, the forward voltage of the described light emitting diode that gathers described test constant current source module output by sampling module under the described measuring current cycle;
Described self-calibration module, for eliminating the physical parameter of described light emitting diode self, obtains the change in voltage that described light emitting diode is caused by temperature effect, and outputs to demonstration in DVM 3.
Described quick handover module, by the P utmost point of described two fast recovery diode D1 and D2 connecting test constant flow module and drive constant flow module respectively, described D1 and the N of D2 are extremely directly of coupled connections with described light emitting diode, the P utmost point of D2 is connected to the source electrode of the N-channel MOS FET pipe Q1 of power level by sampling resistor Rx, described driving signal is connected with the grid of described MOSFET pipe Q1 by described optocoupler U101, described resistance R 101 and R102 are connected on respectively input end and the output terminal of described U101, play on-off action.When circuit is demarcating during state, control described driving signal and be output as low level, described U101 conducting, it is output as high level, controls described MOSFET pipe Q1 conducting, and the output current of described driving constant current source module is bypassed.When circuit is during in test mode, controlling described driving signal is pulse signal.Between pulse signal high period, described U101 is high-impedance state, and described MOSFET pipe Q1 is in cut-off state, and described driving constant flow module and described test constant flow module output to described light emitting diode jointly, and it is heated.Between pulse signal low period, described U101 and the equal conducting of described MOSFET pipe Q1, drive current is bypassed, and makes the forward voltage that only has described test constant current to cause on described light emitting diode.Described D1 and D2 guarantee that the current conversion time of described quick handover module is in ns level;
Described time delay sampling module comprises signal lag processing module and sampling module, and described signal lag processing module comprises time delay sampled signal unit and drives signal element.Described clock signal is connected to the clock end of described counter U201, described counter U201 and U202 series connection, the output of two connects two input ends of Sheffer stroke gate U203, form a frequency dividing circuit, output duty cycle is 1% sampling pulse, be connected to the input end of described Sheffer stroke gate U204, another input end of described U204 connects described single-pole double-throw switch (SPDT) S201, the described resistance R 201 diode D201 that connects, the output terminal that resistance R 202 is connected respectively described S201 with capacitor C 201, to ground, shows for filtering clutter and state.Described R203 is connected with described U204 output terminal with the charging and discharging circuit that C203 forms, what described U205 and U207, consist of exports time delay sampled signal with exclusive disjunction circuit, the exclusive disjunction circuit output drive pulse signal consisting of described U206 and U208.The P end of described light emitting diode to be measured is connected to the in-phase end of the voltage follower consisting of amplifier A201, the output of described A201 connects by R204, the analog sampling circuit that analog switch A and capacitor C 204 form, the control end of described analog switch A connects described time delay sampling pulse signal, the output of described analog switch A is connected to the in-phase input end of the voltage follower consisting of amplifier A202, output sampled signal.
When described S201 is placed in demarcation end, described U204 at one end, under low level input, is output as high level, and described time delay sampling pulse and described drive pulse signal are high level, analog switch A conducting, the forward voltage that sampled signal is light emitting diode to be measured.When described S201 is placed in test lead, described U204 is output as the sampling pulse that described dutycycle is 1%, in described time delay sampling pulse signal high level period, analog switch A conducting, export the forward voltage of light emitting diode to be measured, in described time delay sampling pulse signal low-level period, analog switch A cut-off, sampled signal enters hold mode.
Described self-calibration module comprises with reference to LED, stabilized voltage supply U301, three operational amplifier A 301, A302, A303, eight resistance R 301～R308.
Wherein, described test constant current source module is connected with the end of oppisite phase of operational amplifier A 301 by resistance R 301, the in-phase end of described A301 is by resistance R 302 ground connection, described reference LED connects reversed-phase output and the output terminal of described A301, formation is with reference to LED negative circuit, and output is with reference to LED test voltage signal.The positive and negative reference voltage end of described stabilized voltage supply U301 is connected to respectively 1 end and 2 ends of described slide rheostat Rg, (3 ends are connected to the in-phase input end of the voltage follower being comprised of described operational amplifier A 302 to the tap terminals of described slide rheostat Rg, according to the change in resistance of described slide rheostat Rg, form zeroing circuit, output zeroing signal.Described sampled signal, with reference to LED test voltage signal, zeroing signal is by described resistance R 303, R304 and R305 coupling, by resistance R 306 ground connection, and be input to the in-phase input end of operational amplifier A 303, the output terminal of described amplifier A303 is by described resistance R 307 and resistance R 308 ground connection, and by the Voltage Feedback at described resistance R 308 two ends the inverting input to described amplifier A303, form in-phase proportion amplifying circuit.
Under reliability environment, when described single-pole double-throw switch (SPDT) S201 is placed in demarcation end, sampled signal is the measuring current of described test constant flow module output at the forward voltage of light emitting diode to be measured two ends generation, described reference LED test voltage signal is for test constant current is in the negative value of the forward voltage producing with reference to LED two ends, described zeroing circuit, by described Rg output small voltage, regulates the zero point of whole circuit.When described single-pole double-throw switch (SPDT) S201 is placed in test lead, sampled signal is captured in the forward voltage of light emitting diode to be measured described under measuring current in the different temperatures period, described reference LED is output as the forward voltage that the measuring current under normal temperature causes, zeroing signal keeps stable in this process, the in-phase proportion amplifying circuit output variations injunction temperature signal consisting of described A303.
Finally it should be noted that: above embodiment is only for illustrating technical scheme of the present invention, not for limitation of the present invention, although the present invention is had been described in detail with reference to above-described embodiment, it will be understood by those skilled in the art that: still can modify or be equal to replacement the specific embodiment of the present invention, and do not depart from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed within the scope of claim of the present invention.
Claims (5)
1. the junction temperature observation circuit of a great power LED fail-test, it is characterized in that: comprise and drive constant current source module (500), test constant current source module (400), quick handover module (100), described time delay sampling module (200) and self calibration module (300), wherein
Described driving constant current source module is electrically connected LED to be measured, and described LED to be measured is heated;
The described LED to be measured of described test constant-current source circuit electrical connection, provides described LED to be measured to test required electric current;
Described quick handover module, acts on light emitting diode to be measured for the output current of controlling described driving constant flow module in the heating cycle of described LED to be measured, test period is bypassed to ground;
Described time delay sampling module, connect crystal oscillator (201) and provide standard clock signal by described crystal oscillator, produce gating pulse sequential, the forward voltage of the LED described to be measured (10) that gathers described test constant current source module output based on described gating pulse sequential under the described measuring current cycle;
Described self-calibration module electrical connection the 3rd DVM (301), described self-calibration module is by LED more to be measured with reference to LED, eliminating the physical property that LED to be measured causes by electric current changes, the junction temperature of on-line monitoring LED to be measured under different reliability environments, obtain the change in voltage that described LED to be measured is caused by temperature effect, and described Voltage-output to described the 3rd DVM is shown;
Described system also comprises the first sample resistance (R for testing constant current source module output current described in sampling monitoring
ts) and the first DVM (401), for driving the second sample resistance (R of constant current source module output current described in sampling monitoring
ds) and the second DVM (501).
2. the junction temperature observation circuit system of great power LED fail-test according to claim 1, it is characterized in that: described delay sampling circuit comprises the first counter and the second counter that are connected in series, the clock end of described the first counter and the second counter is connected crystal oscillator, described crystal oscillator clock signal, the output terminal of described the first counter (U201) and the second counter (U202) is connected with two input ends of the first Sheffer stroke gate (U203) respectively, form a frequency dividing circuit, the output terminal of described the first Sheffer stroke gate connects an input end of the second Sheffer stroke gate, described frequency dividing circuit output sampling pulse is to described the second Sheffer stroke gate (U204), the moved end of single-pole double-throw switch (SPDT) (S201) connects reference voltage+12V, a motionless terminal is for demarcating end, another motionless terminal is test lead, described demarcation holds unsettled connection to be high-impedance state, described test lead connects two input ends of described the second Sheffer stroke gate, the first filter resistance (R201) series connection the first filtering diode (D201), the test lead that the second filter resistance (R202) is connected respectively described single-pole double-throw switch (SPDT) with described the first filter capacitor is to ground, for filtering clutter and condition prompting,
The 3rd resistance (R203) is connected with the 3rd Sheffer stroke gate (U204) output terminal with the charging and discharging circuit that the first electric capacity (C203) forms, what the 4th Sheffer stroke gate (U205) and the first rejection gate (U207), consist of exports time delay sampled signal with exclusive disjunction circuit, the exclusive disjunction circuit output drive pulse signal consisting of the second rejection gate (U206) and the 3rd rejection gate (U208); The P end of described LED to be measured is connected to the in-phase input end of the voltage follower consisting of the first amplifier (A201), the output of described the first amplifier (A201) is connected to by the 4th resistance (R204), the analog sampling circuit that analog switch A and the second electric capacity (C204) form, the control end of described analog switch A connects described time delay sampling pulse signal, the output of described analog switch A is connected to the in-phase input end of the voltage follower consisting of the second amplifier (A202), output sampled signal;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, the 3rd Sheffer stroke gate (U204) is at one end under low level input, be output as high level, described time delay sampling pulse and described drive pulse signal are high level, analog switch A conducting, the forward voltage that sampled signal is LED to be measured;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, the 3rd described Sheffer stroke gate U204 is output as the sampling pulse that described dutycycle is 1%, in described time delay sampling pulse signal high level period, analog switch A conducting, export the forward voltage of light emitting diode to be measured, in described time delay sampling pulse signal low-level period, analog switch A cut-off, sampled signal enters hold mode.
3. the junction temperature observation circuit system of great power LED fail-test according to claim 2, it is characterized in that: described fast switch circuit comprises optocoupler, the first metal-oxide-semiconductor that described optocoupler connects, the input end of described optocoupler and output terminal are serially connected with respectively the first switch resistance and second switch resistance, described optocoupler is connected with the grid of the first metal-oxide-semiconductor, described fast switch circuit unit also comprises the first diode and the second diode, described the first diode is connected to being connected on branch road of described test constant current source and described LED to be measured, described the second diode is connected to being connected on branch road of described driving constant current source and described LED to be measured, the described second diode P utmost point connects the source electrode of described the first metal-oxide-semiconductor by the first sampling resistor, described optocoupler is connected with the drive pulse signal output terminal of described delay sampling circuit,
When described single-pole double-throw switch (SPDT) S201 is placed in, demarcate when end, control described driving signal and be output as low level, described optocoupler conducting output high level, the first metal-oxide-semiconductor conducting described in described optocoupler control, the output current of described driving constant-current source circuit is bypassed;
When described single-pole double-throw switch (SPDT) S201 is placed in test lead, controlling described driving signal is pulse signal, between pulse signal high period, described optocoupler is high-impedance state, described the first metal-oxide-semiconductor is in cut-off state, described driving constant-current circuit and described test constant-current circuit output to described LED to be measured jointly, and it is heated;
Between pulse signal low period, described optocoupler and the equal conducting of described the first metal-oxide-semiconductor, drive current is bypassed, and makes the forward voltage that only has described test constant current to cause on described LED to be measured.
4. the junction temperature observation circuit system of great power LED fail-test according to claim 3, it is characterized in that: described self-calibration module comprises with reference to LED, stabilized voltage supply (U301), three operational amplifier the 3rd operational amplifiers (A301), four-operational amplifier (A302), the 5th operational amplifier (A303), eight test resistance, the first test resistance, the second test resistance, the 3rd test resistance, the 4th test resistance, the 5th test resistance, the 6th test resistance, the 7th test resistance, the 8th test resistance (R301～R308).
Wherein, described test constant current source module is connected with the end of oppisite phase of the first operational amplifier (A301) by the first resistance (R301), the in-phase end of the 3rd described operational amplifier (A301) is by the second test resistance (R302) ground connection, described reference LED connects inverting input and the output terminal of the 3rd described operational amplifier (A301), formation is with reference to LED negative circuit, and output is with reference to LED reverse voltage signal.The positive and negative reference voltage end of described stabilized voltage supply (U301) is connected to respectively slide rheostat two ends, the tap terminals of described slide rheostat Rg is connected to the in-phase input end of the voltage follower being comprised of described four-operational amplifier (A302), according to the change in resistance of described slide rheostat Rg, form zeroing circuit, output zeroing signal; Described sampled signal, with reference to LED test voltage signal, zeroing signal is by the 3rd described test resistance, the 4th test resistance, the 5th test resistance coupling, by the 6th test resistance (R306) ground connection, and be input to the in-phase input end of the 5th operational amplifier (A303), the output terminal of described the 5th operational amplifier (A303) is by described the 7th test resistance, the 8th test resistance ground connection, and by the Voltage Feedback at described the 8th test resistance two ends to the inverting input of described the 5th operational amplifier, form in-phase proportion amplifying circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in demarcation end, sampled signal is the measuring current of described test constant flow module output at the forward voltage of light emitting diode to be measured two ends generation, described reference LED test voltage signal is for test constant current is in the negative value of the forward voltage producing with reference to LED two ends, described zeroing circuit, by described Rg output small voltage, regulates the zero point of whole circuit;
When described single-pole double-throw switch (SPDT) (S201) is placed in test lead, sampled signal is captured in the forward voltage of light emitting diode to be measured described under measuring current in the different temperatures period, described reference LED is output as the forward voltage that the measuring current under normal temperature causes, zeroing signal keeps stable in this process, the in-phase proportion amplifying circuit output variations injunction temperature signal consisting of described (A303).
5. a junction temperature monitoring method for great power LED fail-test, comprises and it is characterized in that the junction temperature observation circuit of the great power LED fail-test as described in as arbitrary in claim 1-4, and described method comprises:
Step S1, use single-pole double-throw switch (SPDT) (S201), controlling described the first rejection gate (U207) and the second rejection gate (U208) output terminal is high level, makes the forward output voltage under described analog switch A continuous acquisition measuring current;
Step S2, carries out initialization by the zeroing circuit of described four-operational amplifier (A302) and described (U301) to on-line monitoring circuit;
Step S3, given described reference LED and the difference of LED environment temperature to be measured, the forward voltage of measuring under this difference changes, and junction temperature transduction factor is demarcated;
Step S4, reliability junction temperature on-line testing link is used single-pole double-throw switch (SPDT) (S201), controls LED forward voltage signal maintenance under described analog switch A quick sampling measuring current;
Step S5, calculates the variations injunction temperature value of LED to be measured under fail-test environment according to the junction temperature transduction factor of demarcating, and adds test ambient temperature, obtains final LED junction temperature value to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410006434.2A CN103728037B (en) | 2014-01-07 | 2014-01-07 | Junction temperature monitoring circuit system for high-power LED reliability test |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410006434.2A CN103728037B (en) | 2014-01-07 | 2014-01-07 | Junction temperature monitoring circuit system for high-power LED reliability test |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103728037A true CN103728037A (en) | 2014-04-16 |
| CN103728037B CN103728037B (en) | 2017-01-11 |
Family
ID=50452212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410006434.2A Expired - Fee Related CN103728037B (en) | 2014-01-07 | 2014-01-07 | Junction temperature monitoring circuit system for high-power LED reliability test |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103728037B (en) |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104090224A (en) * | 2014-07-18 | 2014-10-08 | 浙江大学 | On-line detection system and method for work junction temperature of power diode module |
| CN104316215A (en) * | 2014-11-10 | 2015-01-28 | 常州工学院 | Device and method for measuring junction temperature of LED through bridge |
| CN104748885A (en) * | 2015-04-27 | 2015-07-01 | 厦门大学 | Method for measuring LED (Light Emitting Diode) junction temperature based on I-V feature curve |
| CN105759223A (en) * | 2016-03-21 | 2016-07-13 | 上海时代之光照明电器检测有限公司 | Method for detecting luminous flux maintenance life of LED lamp |
| CN105842634A (en) * | 2016-03-21 | 2016-08-10 | 上海时代之光照明电器检测有限公司 | Method for detecting luminance attenuation of LED lamp |
| CN107515043A (en) * | 2017-09-14 | 2017-12-26 | 合肥彩虹蓝光科技有限公司 | A kind of method of testing of LED chip luminous power |
| CN107621599A (en) * | 2017-08-28 | 2018-01-23 | 北京工业大学 | A kind of method of measurement IGBT variations injunction temperatures in high temperature reverse bias experiment |
| CN108872758A (en) * | 2018-05-10 | 2018-11-23 | 江苏大学 | A kind of electronic component life detecting device |
| CN110308312A (en) * | 2019-08-08 | 2019-10-08 | 南京芯长征科技有限公司 | It is able to achieve the method and device of Hi-pot test mesohigh isolation |
| CN111999630A (en) * | 2020-10-28 | 2020-11-27 | 四川立泰电子有限公司 | Method and system for testing working junction temperature of power device |
| CN112014708A (en) * | 2020-07-27 | 2020-12-01 | 西安中车永电电气有限公司 | SiC power device online junction temperature calculation method based on FPGA |
| CN112816784A (en) * | 2020-12-31 | 2021-05-18 | 广电计量检测（成都）有限公司 | Resistance test circuit and system |
| CN113030682A (en) * | 2021-03-12 | 2021-06-25 | 中国科学院电工研究所 | High-precision junction temperature online monitoring method and system |
| CN114487757A (en) * | 2022-04-14 | 2022-05-13 | 长沙丹芬瑞电气技术有限公司 | Detection apparatus for field effect transistor health status and power supply |
| CN115754650A (en) * | 2023-01-10 | 2023-03-07 | 迈思普电子股份有限公司 | Diade-IFSM-Tj test fixture |
| CN115980502A (en) * | 2023-03-20 | 2023-04-18 | 宁波群芯微电子股份有限公司 | Optocoupler driving capability test method and system |
| CN117907653A (en) * | 2024-02-26 | 2024-04-19 | 此芯科技(苏州)有限公司 | Load simulation equipment and chip power supply platform verification method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992667A (en) * | 2017-05-22 | 2017-07-28 | 江苏现代电力科技股份有限公司 | A kind of constant-current drive circuit |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1306303A (en) * | 2001-02-28 | 2001-08-01 | 山东大学 | Steady-state service life test method by controlling junction temp of transistor |
| US20030133491A1 (en) * | 2002-01-04 | 2003-07-17 | Kelvin Shih | LED junction temperature tester |
| JP2005115350A (en) * | 2003-09-17 | 2005-04-28 | Seiko Epson Corp | Temperature measuring device, light source controller, projector, temperature measuring method and light source control method |
| TW200923393A (en) * | 2007-11-23 | 2009-06-01 | Ind Tech Res Inst | Devices and methods for LED life test |
| CN101452044A (en) * | 2007-12-07 | 2009-06-10 | 财团法人工业技术研究院 | LED life test apparatus and method |
-
2014
- 2014-01-07 CN CN201410006434.2A patent/CN103728037B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1306303A (en) * | 2001-02-28 | 2001-08-01 | 山东大学 | Steady-state service life test method by controlling junction temp of transistor |
| US20030133491A1 (en) * | 2002-01-04 | 2003-07-17 | Kelvin Shih | LED junction temperature tester |
| JP2005115350A (en) * | 2003-09-17 | 2005-04-28 | Seiko Epson Corp | Temperature measuring device, light source controller, projector, temperature measuring method and light source control method |
| TW200923393A (en) * | 2007-11-23 | 2009-06-01 | Ind Tech Res Inst | Devices and methods for LED life test |
| CN101452044A (en) * | 2007-12-07 | 2009-06-10 | 财团法人工业技术研究院 | LED life test apparatus and method |
Non-Patent Citations (1)
| Title |
|---|
| 陈全: "大功率LED结温测试及其在封装热管理中的应用研究", 《中国博士学位论文全文数据库 信息科技辑》, 15 August 2012 (2012-08-15) * |
Cited By (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104090224B (en) * | 2014-07-18 | 2016-10-05 | 浙江大学 | The on-line detecting system of a kind of power diode module working junction temperature and detection method |
| CN104090224A (en) * | 2014-07-18 | 2014-10-08 | 浙江大学 | On-line detection system and method for work junction temperature of power diode module |
| CN104316215A (en) * | 2014-11-10 | 2015-01-28 | 常州工学院 | Device and method for measuring junction temperature of LED through bridge |
| CN104748885A (en) * | 2015-04-27 | 2015-07-01 | 厦门大学 | Method for measuring LED (Light Emitting Diode) junction temperature based on I-V feature curve |
| CN105759223A (en) * | 2016-03-21 | 2016-07-13 | 上海时代之光照明电器检测有限公司 | Method for detecting luminous flux maintenance life of LED lamp |
| CN105842634A (en) * | 2016-03-21 | 2016-08-10 | 上海时代之光照明电器检测有限公司 | Method for detecting luminance attenuation of LED lamp |
| CN107621599B (en) * | 2017-08-28 | 2020-02-04 | 北京工业大学 | Method for measuring junction temperature change of IGBT in high-temperature reverse bias test |
| CN107621599A (en) * | 2017-08-28 | 2018-01-23 | 北京工业大学 | A kind of method of measurement IGBT variations injunction temperatures in high temperature reverse bias experiment |
| CN107515043B (en) * | 2017-09-14 | 2020-06-12 | 合肥彩虹蓝光科技有限公司 | Method for testing light power of LED chip |
| CN107515043A (en) * | 2017-09-14 | 2017-12-26 | 合肥彩虹蓝光科技有限公司 | A kind of method of testing of LED chip luminous power |
| CN108872758B (en) * | 2018-05-10 | 2019-06-28 | 江苏大学 | A kind of electronic component life detecting device |
| GB2578370B (en) * | 2018-05-10 | 2022-03-23 | Univ Jiangsu | A device for measuring lifetime of electronic components |
| WO2019213994A1 (en) * | 2018-05-10 | 2019-11-14 | 江苏大学 | Device for detecting service life of electronic component |
| CN108872758A (en) * | 2018-05-10 | 2018-11-23 | 江苏大学 | A kind of electronic component life detecting device |
| GB2578370A (en) * | 2018-05-10 | 2020-05-06 | Univ Jiangsu | Device for detecting service life of electronic component |
| CN110308312B (en) * | 2019-08-08 | 2021-04-23 | 南京芯长征科技有限公司 | Method and device capable of realizing high-voltage isolation in high-voltage test |
| CN110308312A (en) * | 2019-08-08 | 2019-10-08 | 南京芯长征科技有限公司 | It is able to achieve the method and device of Hi-pot test mesohigh isolation |
| CN112014708A (en) * | 2020-07-27 | 2020-12-01 | 西安中车永电电气有限公司 | SiC power device online junction temperature calculation method based on FPGA |
| CN112014708B (en) * | 2020-07-27 | 2023-02-07 | 西安中车永电电气有限公司 | SiC power device online junction temperature calculation method based on FPGA |
| CN111999630A (en) * | 2020-10-28 | 2020-11-27 | 四川立泰电子有限公司 | Method and system for testing working junction temperature of power device |
| CN112816784A (en) * | 2020-12-31 | 2021-05-18 | 广电计量检测（成都）有限公司 | Resistance test circuit and system |
| CN113030682A (en) * | 2021-03-12 | 2021-06-25 | 中国科学院电工研究所 | High-precision junction temperature online monitoring method and system |
| CN113030682B (en) * | 2021-03-12 | 2023-07-28 | 中国科学院电工研究所 | High-precision junction temperature online monitoring method and system |
| CN114487757A (en) * | 2022-04-14 | 2022-05-13 | 长沙丹芬瑞电气技术有限公司 | Detection apparatus for field effect transistor health status and power supply |
| CN115754650A (en) * | 2023-01-10 | 2023-03-07 | 迈思普电子股份有限公司 | Diade-IFSM-Tj test fixture |
| CN115980502A (en) * | 2023-03-20 | 2023-04-18 | 宁波群芯微电子股份有限公司 | Optocoupler driving capability test method and system |
| CN117907653A (en) * | 2024-02-26 | 2024-04-19 | 此芯科技(苏州)有限公司 | Load simulation equipment and chip power supply platform verification method |
| CN117907653B (en) * | 2024-02-26 | 2024-05-31 | 此芯科技(苏州)有限公司 | Load simulation equipment and chip power supply platform verification method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103728037B (en) | 2017-01-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103728037A (en) | Junction temperature monitoring circuit system for high-power LED reliability test | |
| US8841916B2 (en) | System and method for flash bypass | |
| CN104090224B (en) | The on-line detecting system of a kind of power diode module working junction temperature and detection method | |
| CN102186276B (en) | LED (light emitting diode) constant current driving circuit with current detection and LED backlight system | |
| CN108828428A (en) | Insulated test device | |
| CN101769957A (en) | Automatic switching circuit for voltage and current measurement and method thereof | |
| CN106535391B (en) | Peak current absorbing circuit and its control method and light emitting diode drive device | |
| CN104360143A (en) | Load zero crossing point detection circuit and method and load voltage detection circuit and method | |
| CN102879722A (en) | Volt-ampere performance testing device and method for solar array | |
| CN103954872B (en) | Transformer temperature rise measuring device and method | |
| CN103454581A (en) | Contactor performance testing equipment | |
| Maffezzoni et al. | Compact electrothermal macromodeling of photovoltaic modules | |
| CN101893677B (en) | Test device and test method of triode under reverse biased safe operating area | |
| CN103852733A (en) | LED power supply performance analysis device and method | |
| CN103983882B (en) | The device and method of detection digital input signals wire connectivity | |
| CN203643537U (en) | Aging test system of uncooled semiconductor laser | |
| CN210865578U (en) | Power consumption detection circuit of display panel | |
| CN208752169U (en) | A kind of bypass diode test device | |
| CN207440201U (en) | A kind of condenser leakage current multichannel independent test system | |
| CN203929854U (en) | Voltage magnitude testing circuit | |
| CN104980105A (en) | Method for testing maximum power point tracing algorithm performance of solar photovoltaic power generation system | |
| CN105425022A (en) | Simple detection circuit for mains voltage | |
| CN110007249A (en) | A kind of LED light driving power test method, apparatus and system | |
| CN202041872U (en) | Automatic power control device | |
| CN204330872U (en) | The load voltage testing circuit of current zero-crossing point testing circuit and correspondence |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170111 Termination date: 20200107 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |