Test Report 004 Single Event Effects (SEE) Testing of the ISL71840SEH 16:1 30V Mux Introduction SEE Test Objectives The intense proton and heavy ion environment encountered in space applications can cause a variety of Single Event Effects (SEE) in electronic circuitry, including Single Event Upset (SEU), Single Event Transient (SET), Single Event Functional Interrupt (SEFI), Single Event Gate Rupture (SEGR), and Single Event Burnout (SEB). Single event effects can lead to system-level performance issues including disruption, degradation and destruction. For predictable and reliable space system operation, individual electronic components should be characterized to determine their SEE response. This report discusses the results of SEE testing performed on the Intersil ISL71840SEH 16:1 multiplexer (MUX) designed for space applications. The ISL71840SEH was tested to determine its susceptibility to destructive single event effects (SEGR and SEB, collectively referred to by SEB) and to characterize its Single Event Transient (SET) behavior over various conditions and ion Linear Energy Transfer (LET) levels. The ISL71840SEH parts tested came from lot J67669.1, wafer #3 manufactured on Intersil’s proprietary P6SOI process. Product Description The ISL71840SEH is a 16:1 analog multiplexer (MUX) that operates with supply voltages from ±10.8V to ±16.5V and input overvoltage capability to ±35V. The part is also “cold spare” capable; i.e., inputs of an unpowered part do not leak more than 1µA to ±35V. The ISL71840SEH is fabricated in a proprietary Intersil bonded wafer SOI BiCMOS process. Product Documentation For more information about the ISL71840SEH, refer to the following documentation. • ISL71840SEH datasheet • Standard Microcircuit Drawing (SMD): 5962-15219 • UG028 “ISL71840SEHEV1Z Evaluation Board User Guide” SEE Test Facility Testing was performed at the Texas A&M University (TAMU) Cyclotron Institute heavy ion facility. This facility is coupled to a K500 super-conducting cyclotron, which is capable of generating a wide range of test particles with the various energy, flux and fluence levels needed for advanced radiation testing. Details on the test facility can be found on the TAMU Cyclotron website. Testing was carried out on December 15th and 16th of 2014. SEE Test Set-up SEE testing was carried out with the sample in an active configuration. A schematic of the ISL71840SEH SEE test fixture is shown in Figure 1. The test circuit is configured to accept variable supply voltages and two groupings of variable input voltages. The addressing of input IN13 is accomplished with either logic threshold inputs (SW1 closed for 16% and 80% of VREF) or with railed logic inputs (SW1 open for VREF and GND). The output is set to half of VIN13-GND by a resistor divider formed from VIN13 to GND. The ISL71840SEH samples were in standard ceramic flatpack packages without lids and were assembled on boards that allowed two parts to be irradiated at one time. A 20-foot coaxial cable was used to connect the test fixture to a switch box in the control room, which contained all of the monitoring equipment. The switch box allowed the two test circuits to be controlled and monitored remotely. Digital multimeters were used to monitor pertinent voltages and currents. LeCroy waveRunner 4-channel digital oscilloscopes were used to capture and store SET traces at VOUT that exceeded the oscilloscopes’ ±20mV AC trigger setting. April 30, 2015 TR004.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2015. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Test Report 004 10k V+ IS+ VINHI IINHI +VS 1 28 OUT NC 2 27 ‐VS NC 3 26 IN 8 IN 16 4 25 IN 7 IN 15 5 24 IN 6 IN 14 6 23 IN 5 IN 13 7 22 IN 4 IN 12 8 21 IN 3 IN 11 9 20 IN 2 IN 10 10 19 IN 1 IN 9 11 18 ENABLE GND 12 17 ADDR A0 VREF 13 16 ADDR A1 ADDR A3 14 15 ADDR A2 VOUT VISVINLO IINLO VIN13 IIN13 10k VREF IREF 1k SW1 3.2k 800 80% VREF (4V @ VREF=5V) with SW1 closed, VREF when open 16% VREF (0.8V @ VREF=5V) with SW1 closed, GND when open FIGURE 1. SCHEMATIC OF THE ISL71840SEH SEE TESTING CONFIGURATION SEE Damage (SEB) Testing For the destructive SEE (SEB) tests, conditions were selected to maximize the electrical and thermal stresses on the device under test (DUT), thus insuring worst-case conditions. The supply voltages were set to the part’s absolute maximum rating of ±20V. The input voltages were set to ±17V and ±35V to stress the switches at relevant extreme conditions. Case temperature was maintained at +125ºC by controlling the current flowing into a resistive heater bonded to the underside of the board. Four DUTs were irradiated with 2.954GeV Au ions at normal incidence resulting in a surface LET = 86.4MeV•cm2/mg. The normal range into silicon for these Au ions after 30mm of air is about 118µm with a Bragg peak range of 53µm. More detail can be found on the TAMU Cyclotron website. These conditions guaranteed ions transited all active device volume in this SOI process (about 10µm depth). The switch SW1 in the OPEN condition provided railed (GND and VREF) enable and address lines to the parts. Table 1 summarizes the SEB testing conditions. Submit Document Feedback 2 TABLE 1. SEB TESTING CONDITIONS EFFECTIVE LET NUMBER (MeV•cm2/ OF TESTS mg) SW1 ±VS (V) VIN13 VINLO VINHI VREF (V) Test 1 86.4 OPEN ±20 1.0 -17.00 17.00 +20 Test 2 86.4 OPEN ±20 1.0 -35.00 35.00 +20 NOTE: Exposure was with 2.954GeV Au at 0º incidence for LET = 86MeV•cm2/mg to a fluence of 5x106 ions/cm2 at case temperature of +125ºC for each test. TR004.0 April 30, 2015 Test Report 004 The set of parameters monitored to look for indications of device damage along with the actual measurements appear in Table 2. The currents represent the sum of the currents for two DUTs as called out in Table 2. In all cases, the changes in parameters were within the 8% change of measurement repeatability without the beam and so it was concluded that there was no permanent damage sustained by the parts for any of the SEB testing completed. Each irradiation was carried out to a fluence of 5x106 ions/cm2. From this data the ISL71840SEH is deemed to have an SEB cross section of less than 1.5x10-7cm2 to a confidence of 95% for either test case. Combining all the results for both tests drives the SEB cross section down to 7.5x10-8 cm2 at a 95% confidence. TABLE 2. SEB MONITOR PARAMETERS FOR TESTING AT LET0º = 86.4 MeV•cm2/mg and TCASE = +125ºC DELTA FAILURE CRITERIA 0.005 8% 8% 8% MONITORED PARAMETER VOUT (V) IS+ (µA) IS(µA) IREF (µA) Pre 0.000 516 512 339 Post 0.000 513 512 340 Pre 0.000 501 499 343 Post 0.000 495 495 342 Pre 0.000 578 574 337 Post 0.000 536 536 337 Pre 0.000 485 482 337 Post 0.000 483 483 338 DUT1 + DUT2 Test 1 Test 2 DUT3 + DUT4 Test 1 Test 2 SET Testing of ISL71840SEH 16:1 Analog MUX SET testing was done on four samples of the ISL71840SEH. Testing started with gold (Au) at LET0º = 86.4MeV•cm2/mg and with the SET detection threshold set to ±20mV deviation AC-coupled on VOUT. Subsequently, the test LET was reduced to 43MeV•cm2/mg (Ag at 0° incidence) and then finally to 20MeV•cm2/mg (Cu at 0° incidence). Two separate conditions as shown in Table 3 were applied to each of the four parts tested. TABLE 3. SET TESTING CONDITIONS NUMBER OF TESTS SW1 VS± (V) VIN13 VINLO (V) VINHI (V) VREF (V) Test 1 CLOSED ±10.8 1.00 -10.8 10.8 4.5 Test 2 CLOSED ±16.5 1.00 -16.5 16.5 4.5 The first test, tests the part operating at the bottom of the recommended supply voltage range, ±10.8V. The second test exercises the part at the maximum of the supply voltage range, ±16.5V. In both cases the VREF is set to the minimum of the recommended operating range of 4.5V to minimize the noise margin in the addressing circuits. The lower noise margins makes the addressing most susceptible to an SEE that could lead to an address change SET. Table 4 on page 4 summarizes the SET counts for each test by DUT and then reports the nominal SET cross section for the complement of all four DUTs. The cross sections reported are the nominal found by dividing the event counts by the total fluence generating those counts. NOTE: Each irradiation was to a fluence of 5x106 ions/cm2. No parameter deltas exceeded failure criteria. Submit Document Feedback 3 TR004.0 April 30, 2015 Test Report 004 TABLE 4. ±20mV SET COUNTS FOR TESTING OF THE ISL71840SEH. TEST LET and FLUENCE PER TEST TEST CONFIGURATIONS DUT1 ±20mV EVENT COUNTS DUT2 ±20mV EVENT COUNTS DUT3 ±20mV EVENT COUNTS DUT4 ±20mV EVENT COUNTS TOTAL CROSS SECTION (cm2) COMBINED TEST CROSS SECTION (cm2) 3.23x10-4 LET = 86 4x106 Test 1, ±10.8 V 1153 1024 1332 1116 2.89x10-4 Test 2, ±16.5 V 1524 1371 1275 1561 3.58x10-4 LET = 43 4x106 Test 1, ±10.8 V 91 79 62 72 1.90x10-5 Test 2, ±16.5 V 78 80 86 71 2.25x10-5 LET = 20 4x106 Test 1, ±10.8 V 3 0 - - 3.75x10-7 Test 2, ±16.5 V 1 2 - - 3.75x10-7 2.08x10-5 3.75x10-7 NOTE: LET listed in MeV•cm2/mg and fluence in ions/cm2. Post processing of the captured SET oscilloscope traces, generated the composite plots in Figures 2 through 9 for the LET = 86.4 MeV•cm2/mg case. These plots show the composite of the 20 largest and 20 longest for each sense of the extreme deviation (positive and negative) so they reflect at most the worst 80 SETs observed in the run. Figures 2 through 9 are truncated at ±0.2V as that was the limit of the oscilloscope range; this range was necessary to allow triggering at ±0.020V. The SET show a step deviation, either positive or negative, followed by an exponential decay. The magnitudes of the SET steps are within about ±0.15V except for one instance and do not appear to indicate any change of the MUX addressing state driving VOUT immediately toward either ±10.8V in Figures 2 through 5 or ±16.5V in Figures 6 through 9. This is expected as redundancy was applied to the address decoding such that an SET causing an addressing change should be impossible. The differences between the DUTs in Figures 2 through 5 SET plots seems more a function of the rarity of the largest and longest events selected for presentation in the plots than different fundamental behaviors of the DUTs. For example, the single largest event seen on DUT4 (lower right plot of Figures 2 through 5 exceeding -0.2V) likely could have occurred in any of the four DUTs but random chance placed that single event in DUT4. The similarity of the bulk of the plotted events combined with this statistical sampling interpretation of the rare events makes it reasonable to view the four DUTs as representing the same general underlying SET behavior. The equivalence of the results in Figures 10 through 13 is much more readily apparent. All four DUTs produced composites that look very similar. Submit Document Feedback 4 TR004.0 April 30, 2015 Test Report 004 0.20 0.20 0.15 0.15 SET DEVIATION (V) SET DEVIATION (V) Composite Plots 0.10 0.05 0 -0.05 0.10 0.05 0 -0.05 -0.10 -0.10 -0.15 -0.15 -0.20 0 5 10 -0.20 15 0 0.20 0.15 0.15 0.10 SET DEVIATION (V) SET DEVIATION (V) 0.20 0.05 0 -0.05 15 10 15 0.10 0.05 0 -0.05 -0.10 -0.10 -0.15 -0.15 -0.20 5 10 FIGURE 3. FIGURE 2. 0 5 TIME (µs) TIME (µs) 10 -0.20 15 0 TIME (µs) 5 TIME (µs) FIGURE 4. FIGURE 5. 0.20 0.20 0.15 0.15 0.10 0.10 SET DEVIATION (V) SET DEVIATION (V) NOTE: Figures 2 through 5 are composite plots of extreme SET for LET = 86.4MeV•cm2/mg for DUT1 through DUT4 with ±10.8 V supplies. Each run was to have a fluence of 4.0x106 ions/cm2. Post processing selected the 20 largest and longest SET in both positive and negative deviations; not all of 80 such plots were unique. The oscilloscope setting limited the captured deviation range to ±0.2V. 0.05 0 -0.05 -0.10 -0.15 -0.20 0.05 0 -0.05 -0.10 -0.15 0 5 TIME (µs) FIGURE 6. Submit Document Feedback 5 10 15 -0.20 0 5 TIME (µs) 10 15 FIGURE 7. TR004.0 April 30, 2015 Test Report 004 0.20 0.20 0.15 0.15 0.10 0.10 SET DEVIATION (V) SET DEVIATION (V) Composite Plots (Continued) 0.05 0 -0.05 -0.10 -0.15 -0.20 0.05 0 -0.05 -0.10 -0.15 0 5 TIME (µs) 10 -0.20 15 0 FIGURE 8. 5 TIME (µs) 10 15 FIGURE 9. 0.20 0.20 0.15 0.15 0.10 0.10 SET DEVIATION (V) SET DEVIATION (V) NOTE: Figures 6 through 9 are composite plot of SET for LET = 86.4MeV•cm2/mg for DUT1 through DUT4 and Test 2, ±16.5 V supplies. Each run was to a fluence of 4.0x106 ions/cm2. Post processing selected the 20 largest and longest SET in both positive and negative deviations; not all of the 80 such plots were unique. The oscilloscope setting limited the deviation range to ±0.2V. 0.05 0 -0.05 -0.10 -0.15 -0.20 0.05 0 -0.05 -0.10 -0.15 0 5 TIME (µs) 10 -0.20 15 0 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 10 15 10 15 FIGURE 11. SET DEVIATION (V) SET DEVIATION (V) FIGURE 10. 5 TIME (µs) 0.05 0 -0.05 -0.10 -0.15 0 5 TIME (µs) FIGURE 12. 10 15 -0.20 0 5 TIME (µs) FIGURE 13. NOTE: Figures 10 through 13 are composite plots of extreme SET for LET = 43MeV•cm2/mg for DUT1 through DUT4 in Test 1, ±10.8V supplies. Each run was to a fluence of 4.0x106 ions/cm2. Post processing selected the 20 largest and longest SET in both positive and negative deviations; not all of 80 such plots were unique. The oscilloscope setting limited the deviation range to ±0.2V Submit Document Feedback 6 TR004.0 April 30, 2015 Test Report 004 0.20 0.20 0.15 0.15 0.10 0.10 SET DEVIATION (V) SET DEVIATION (V) Composite Plots (Continued) 0.05 0 -0.05 -0.10 0 -0.05 -0.10 -0.15 -0.15 -0.20 0.05 0 5 TIME (µs) 10 -0.20 15 0 0.20 0.20 0.15 0.15 0.10 0.05 0 -0.05 15 0 -0.05 -0.15 -0.15 5 TIME (µs) 10 0.05 -0.10 0 15 0.10 -0.10 -0.20 10 FIGURE 15. SET DEVIATION (V) SET DEVIATION (V) FIGURE 14. 5 TIME (µs) 10 15 FIGURE 16. -0.20 0 5 TIME (µs) FIGURE 17. NOTE: Figures 14 through 17 are composite plots of extreme SET for LET = 43MeV•cm2/mg for DUT1 through DUT4 in Test 2, ±16.5 V supplies. Each run was to a fluence of 4.0x106 ions/cm2. Post processing selected the 20 largest and longest SET in both positive and negative deviations; not all of 80 such plots were unique. The oscilloscope setting limited the deviation range to ±0.2V. 0.20 SET DEVIATION (V) 0.15 0.10 0.05 0 -0.05 No SET captured for DUT2 at ±10.8V -0.10 -0.15 -0.20 -10 -5 0 TIME (µs) FIGURE 18. Submit Document Feedback 7 5 10 FIGURE 19. TR004.0 April 30, 2015 Test Report 004 0.20 0.20 0.15 0.15 0.10 0.10 SET DEVIATION (V) SET DEVIATION (V) Composite Plots (Continued) 0.05 0 -0.05 -0.10 0 -0.05 -0.10 -0.15 -0.15 -0.20 -10 0.05 -5 0 TIME (µs) 5 10 -0.20 -10 FIGURE 20. -5 0 TIME (µs) 5 10 FIGURE 21. NOTE: Figures 18 through 21 are composite plots of extreme SET for LET = 20MeV•cm2/mg for DUT1 and DUT2. Test 1 with ±10.8 V supplies is top row and Test 2 with ±16.5 V supplies is bottom. Each run was to a fluence of 4.0x106 ions/cm2. All captured SETs are plotted. The oscilloscope setting limited the deviation range to ±0.2V. Figures 10 through 17 display the composite SET plots for the cases of LET = 43MeV•cm2/mg. Clearly the SET deviations are of considerably lesser magnitude than for the case of LET = 86MeV•cm2/mg and presage the results for captures at ±20mV for the case of LET = 20MeV•cm2/mg. Figures 18 through 21 represents all of the SET captured at LET = 20MeV•cm2/mg triggering on ±20mV. The low counts encountered for the first four runs (DUT1 and DUT2 at ±10.8 V and ±16.5 V) led to the second pair if devices (DUT3 and DUT4) being skipped. The total of six SET captured and displayed in Figures 18 through 21 are equally distributed positive and negative and all have approximate magnitudes of just over the ±20mV needed for triggering. Discussion and Conclusions SEL and SEB Testing with Au at LET0º = 86MeV•cm2/mg did not result in any indications of SEB or SEGR at applied voltages up to the Absolute Maximum rating of ±20V for supplies and ±35V for inputs. The 2.954GeV Au had a range into silicon of 117µm and a Bragg Range of 53µm putting the Bragg peak well into the inactive handle wafer of the SOI part. Functionality and operational currents monitored did not change as a result of the irradiations carried out at a case temperature of +125ºC. A minimal interpretation of the possible SEB/SEGR cross section is less than 1.5x10-7cm2 to a 95% confidence at LET = 86.4MeV•cm2/mg at incidence of 0º for each of the input voltage conditions (±17V and ±35V). In the total testing the SEB/SEGR possible cross section is less than 7.5x10-8 cm2 at 95% confidence. This is all tantamount to saying that under normal operating conditions the ISL71840SEH is not susceptible to SEB or SEGR failures at up to normal incidence of LET = 86MeV•cm2/mg. SET Results In SET testing no indication of an addressing upset was noted. However, SET testing did result in events exceeding the ±20mV threshold criteria at all LET values tested (86, 43, and 20 MeV•cm2/mg all at normal incidence). The SET events nearly vanished at an LET = 20MeV•cm2/mg yielding a nominal cross section of 3.75x10-7, about 50x smaller than at 43MeV•cm2/mg. However, this probably means that many SET were smaller than the trigger value of ±20mV, not that SET ceased to occur. The total cross section indicated by the SET capture counts topped out at 3.58x10-4 cm2 at LET = 86MeV•cm2/mg. The number of SET captures also depends upon the supply voltages with ±10.8V yielding slightly fewer captured SET than with ±16.5V so that it appears the SET results from instantaneous coupling of the output to one of the supply rails. With a single exception all the SET captured were within ±100mV deviation. The one exception was at -600mV peak and -200mV of output charging at LET = 86MeV•cm2/mg. The observed output SET had decay times of about 15µs. This is likely set by the capacitive loading on VOUT (about 700pF from the cabling) and the resistance setting the nominal voltage (5kΩ). The thus predicted 3.5µs time constant is consistent with that observed. This is important since the application will determine this decay constant and hence the SET duration. The SET study described here utilized a nominal VOUT of 0.5V, very near GND, so that the rails were almost equally far from the nominal output voltage. It should be expected that as the nominal VOUT moves toward a supply rail the SET toward that rail voltage would diminish in magnitude while those toward the opposite rail would increase in magnitude. Thus the worst case SET for a nominal output near a supply rail could be 2x the magnitudes recorded here. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the document is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com Submit Document Feedback 8 TR004.0 April 30, 2015