Neutron testing of the ISL70227SEH hardened dual operational amplifier Nick van Vonno Intersil Corporation 3 November 2013 Revision 0 Table of Contents 1. Introduction 2. Part Description 3. Test Description 3.1 Irradiation facility 3.2 Characterization equipment 3.3 Experimental Matrix 4 Results 4.1 Test results 4.2 Variables data 5 Discussion and conclusion 6 Appendices 7 Document revision history 1. Introduction This report summarizes results of 1 MeV equivalent neutron (‘displacement damage’ or ‘DD’) testing of the ISL70227SEH dual operational amplifier (‘op amp’). The test was conducted in order to determine the sensitivity of the part to displacement damage caused by the neutron environment. Neutron fluences ranged from 5 x 1011 n/cm2 to 1 x 1014 n/cm2 in an approximately logarithmic sequence. This project was carried out in collaboration with Honeywell Aerospace (Clearwater, FL), and their support is gratefully acknowledged. 2: Part Description The ISL70227SEH is a precision dual operational amplifier featuring very low noise, low offset voltage, low input bias current and low temperature drift. These features plus its radiation tolerance make the ISL70227SEH the ideal choice for applications requiring both high DC accuracy and AC performance. The combination of precision performance, low noise and small footprint provides the user with outstanding value and flexibility relative to similar competitive parts. Applications for these amplifiers include active filters and power supply controls. The ISL70227SEH is available in a 10 lead hermetic ceramic flatpack and operates over the extended temperature range of -55°C to +125°C. 1 The ISL70227SEH is implemented in the PR40 process, which is a complementary bipolar flow using bonded wafer DI substrates. The process is used for a wide range of commercial and hardened operational amplifiers, voltage references and temperature sensors. The DI substrate enables vertical NPN and PNP devices, unlike the vertical NPN/lateral PNP combination used in commercial junction isolated processes. The vertical PNP device improves amplifier AC performance and total dose hardness, while the DI substrate eliminates latchup by either electrical or SEE conditions. The PR40 process is in volume production under MIL-PRF-38535 certification in the Palm Bay, Florida Intersil wafer fabrication facility. 3: Test Description 3.1 Irradiation Facilities Neutron irradiation was performed by the Honeywell team at the Fast Burst Reactor (FBR) facility at White Sands Missile Range (White Sands, NM), which provides a controlled 1MeV equivalent neutron flux. Parts were tested in an unbiased configuration with all leads open. As neutron irradiation activates many of the elements found in a packaged integrated circuit, the parts exposed at the higher neutron levels required (as expected) significant ‘cooldown time’ before being shipped back to Palm Bay for electrical testing. 3.2 Characterization equipment and procedures Electrical testing was performed before and after irradiation using the production automated test equipment (ATE). All electrical testing was performed at room temperature. 3.3 Experimental matrix Testing proceeded in general accordance with the guidelines of MIL-STD-883 Test Method 1017. The experimental matrix consisted of five samples irradiated at 5 x 1011 n/cm2, five samples irradiated at 2 x 1012 n/cm2, five samples irradiated at 1 x 1013 n/cm2 and five samples irradiated at 1 x 1014 n/cm2. Two control units were used to insure repeatable data. 4: Results 4.1 Test results Neutron testing of the ISL70227SEH is complete and the results are reported in the balance of this report. 4.2 Variables data The plots in Figs. 1 through 17 show data plots for key parameters before and after irradiation to each level. The plots show the average, minimum and maximum of each parameter as a function of neutron irradiation for each of the two channels, with the exception of the two power supply current plots which report the sum of the supply currents (positive and negative) of both of the two channels. It should be carefully noted when reviewing the data that each neutron irradiation was made on a different 5-unit sample; this is not total dose testing, where the damage is cumulative. For guidance in interpreting the data we show the SMD post-total dose irradiation limits; the ISL70227SEH is not specified or guaranteed for the neutron environment. 2 150.0 Negative input bias current, nA 100 Input offset voltage, µV 100.0 50.0 0.0 -50.0 -100.0 VIO1 Avg VIO1 Min VIO1 Max VIO2 Avg VIO2 Min VIO2 Max Spec limit -150.0 1.00E+11 Pre-rad Spec limit 1.00E+12 1.00E+13 0 -100 -200 -300 -400 -500 -600 -700 -800 Pre-rad 1.00E+11 1.00E+14 50.0 0 40.0 -100 Input offset current, nA Positive input bias current, nA 100 -200 -300 -400 -600 -700 -800 1.00E+11 Pre-rad IB1P Min IB1P Max IB2P Avg IB2P Min IB2P Max Spec limit Spec limit 1.00E+12 1.00E+13 IB2N Avg IB2N Min IB2N Max Spec limit Spec limit 1.00E+12 1.00E+13 1.00E+14 Fig. 3: ISL70227SEH negative input bias current, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limits are -25.0nA to 25.0nA. Fig. 1: ISL70227SEH input offset voltage, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The postirradiation SMD limits are -100.0µV to 100.0µV. IB1P Avg IB1N Min IB1N Max Neutron fluence, n/cm2 Neutron fluence, n/cm2 -500 IB1N Avg 30.0 20.0 IIO1 Avg IIO1 Min IIO1 Max IIO2 Avg IIO2 Min IIO2 Max Spec limit Spec limit 10.0 0.0 -10.0 -20.0 -30.0 -40.0 -50.0 Pre-rad 1.00E+11 1.00E+14 Neutron fluence, n/cm2 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Fig. 4: ISL70227SEH input offset current, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The postirradiation SMD limits are -25.0nA to 25.0nA. Fig. 2: ISL70227SEH positive input bias current, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limits are -25.0nA to 25.0nA. 3 78.0 76.0 AVOL1P Min AVOL1P Max AVOL2P Avg AVOL2P Min AVOL2P Max 117.0 116.0 Spec limit Positive PSRR, dB Positive open loop gain, dB 77.0 118.0 AVOL1P Avg 75.0 74.0 73.0 72.0 71.0 70.0 Pre-rad 1.00E+11 115.0 114.0 113.0 112.0 PSRR1P Avg PSRR1P Min 111.0 PSRR1P Max PSRR2P Avg PSRR2P Min PSRR2P Max 110.0 1.00E+12 1.00E+13 109.0 Pre-rad 1.00E+11 1.00E+14 1.00E+13 1.00E+14 Fig. 7: ISL70227SEH positive power supply rejection ratio (PSRR), each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 110.0dB minimum. Fig. 5: ISL70227SEH positive open-loop voltage gain, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 60.0dB minimum. 120.0 80.0 AVOL1P Avg AVOL1P Min AVOL1P Max AVOL2P Avg AVOL2P Min AVOL2P Max 118.0 Spec limit Negative PSRR, dB Negative open loop gain, dB 1.00E+12 Neutron fluence, n/cm2 Neutron fluence, n/cm2 78.0 Spec limit 76.0 74.0 72.0 116.0 114.0 112.0 110.0 70.0 PSRR1N Avg PSRR1N Min PSRR1N Max PSRR2N Avg PSRR2N Min PSRR2N Max Spec limit 68.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 108.0 Pre-rad 1.00E+11 1.00E+14 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Neutron fluence, n/cm2 Fig. 8: ISL70227SEH negative power supply rejection ratio (PSRR), each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 110.0dB minimum. Fig. 6: ISL70227SEH negative open-loop voltage gain, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 60.0dB minimum. 4 50.0 180.0 45.0 Output current, sourcing, mA Positive CMRR, dB 170.0 160.0 150.0 140.0 130.0 120.0 110.0 100.0 Pre-rad 1.00E+11 CMRR1P Avg CMRR1P Min CMRR1P Max CMRR2P Avg CMRR2P Min CMRR2P Max 35.0 30.0 25.0 20.0 15.0 10.0 5.0 Spec limit 1.00E+12 40.0 1.00E+13 0.0 Pre-rad 1.00E+11 1.00E+14 Neutron fluence, n/cm2 Output current, sinking, mA Negative CMRR, dB 1.00E+14 0.0 170.0 160.0 150.0 140.0 130.0 100.0 Pre-rad 1.00E+11 1.00E+13 Fig. 11: ISL70227SEH sourcing output current, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. A post-irradiation SMD limit is not specified; the 10mA line is an ATE limit. 180.0 110.0 1.00E+12 IO1SRC Min IO2SRC Avg IO2SRC Max Neutron fluence, n/cm2 Fig. 9: ISL70227SEH positive common-mode rejection ratio (CMRR), each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 115.0dB minimum. 120.0 IO1SRC Avg IO1SRC Max IO2SRC Min Spec limit CMRR1P Avg CMRR1P Max CMRR2P Min Spec limit 1.00E+12 CMRR1P Min CMRR2P Avg CMRR2P Max 1.00E+13 -10.0 Neutron fluence, n/cm2 IO1SNK Min IO2SNK Avg IO2SNK Max -20.0 -30.0 -40.0 -50.0 -60.0 Pre-rad 1.00E+11 1.00E+14 IO1SNK Avg IO1SNK Max IO2SNK Min Spec limit 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Fig. 12: ISL70227SEH sinking output current, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. A post-irradiation SMD limit is not specified; the 10mA line is an ATE limit. Fig. 10: ISL70227SEH negative common-mode rejection ratio (CMRR), each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 115.0dB minimum. 5 10.0 3.8 8.0 Negative slew rate, V/µs Supply current, mA 6.0 4.0 2.0 ICC Avg ICC Min 0.0 ICC Max IEE Avg IEE Min IEE Max Spec limit Spec limit -2.0 -4.0 -6.0 3.3 2.8 2.3 -8.0 -10.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 SLEW1N Avg SLEW1N Max SLEW2N Min Spec limit 1.8 1.00E+11 Pre-rad 1.00E+14 Neutron fluence, n/cm2 SLEW1N Min SLEW2N Avg SLEW2N Max 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Fig. 13: ISL70227SEH positive and negative supply current, sum of both channels, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is +/7.4mA maximum. Fig. 15: ISL70227SEH negative slew rate, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 2.0V/µs minimum. 120.0 3.8 3.3 Rise time, ns Postive slew rate, V/µs 100.0 2.8 2.3 1.8 1.00E+11 Pre-rad SLEW1P Avg SLEW1P Max SLEW2P Min Spec limit SLEW1P Min SLEW2P Avg SLEW2P Max 1.00E+12 1.00E+13 TRISE1 Avg TRISE1 Max TRISE2 Min Spec limit TRISE1 Min TRISE2 Avg TRISE2 Max 80.0 60.0 40.0 20.0 0.0 Pre-rad 1.00E+11 1.00E+14 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Neutron fluence, n/cm2 Fig. 16: ISL70227SEH small-signal rise time, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The post-irradiation SMD limit is 100.0ns maximum. Fig. 14: ISL70227SEH positive slew rate, each channel, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control units. The postirradiation SMD limit is 2.0V/µs minimum. 6 units. The post-irradiation SMD limit is 100.0ns maximum. 120.0 Fall time, ns 100.0 TFALL1 Avg TFALL1 Max TFALL2 Min Spec limit TFALL1 Min TFALL2 Avg TFALL2 Max 80.0 60.0 40.0 20.0 0.0 Pre-rad 1.00E+11 1.00E+12 1.00E+13 1.00E+14 Neutron fluence, n/cm2 Fig. 17: ISL70227SEH small-signal fall time, +/-15V supplies, as a function of neutron irradiation. Sample size was 5 for each cell (5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2), with two control 5: Discussion and conclusion This document reports the results of neutron testing of the ISL70227SEH dual operational amplifier. Samples were irradiated to levels of 5 x 1011 n/cm2, 2 x 1012 n/cm2, 1 x 1013 n/cm2 and 1 x 1014 n/cm2. ATE characterization testing was performed before and after the irradiations, and two control units were used to insure repeatable data. Variables data for selected parameters is presented in Figs. 1 through 17. We will discuss the results on a parameter by parameter basis. It should be realized again when reviewing the data that each neutron irradiation was made on a different 5-unit sample; this is not total dose testing, where the damage is cumulative. The 2 x 10 12 n/cm2 level is of some interest in the context of recent developments in the JEDEC community, where the discrete component vendor community have signed up for characterization testing (but not for acceptance testing) at this level. The ISL70227SEH is not formally designed for neutron hardness. The part is built in a DI complementary bipolar process. These bipolar transistors are minority carrier devices, obviously, and may be expected to be sensitive to displacement damage (DD) at the higher levels. This expectation turned out to be correct. We will discuss the results on a parameter by parameter basis and then draw some conclusions. Input parameters are key to operational amplifier performance. The input offset voltage (Fig. 1) showed good stability, with the parameter well within the +/-100µV post-radiation SMD limits. The positive and negative input bias current results (Figs. 2 and 3) were very stable and stayed well within the tight 25.0nA SMD limits through the 1 x 1013 n/cm2 level, and degraded to approximately +/-500nA at the 1 x 1014 n/cm2 level. The input offset current data (Fig. 4) fell within the -25.0nA to 25.0nA SMD limits at the 1 x 1013 n/cm2 level. The positive and negative open-loop voltage gain (Figs. 5 and 6) was stable out to 1 x 1013 n/cm2 but increased significantly at the 1 x 1014 n/cm2 level. The cause of this response is not known. 7 The positive and negative power supply rejection ratio (PSRR) (Figs. 7 and 8) and the positive and negative common-mode rejection ratio (CMRR) (Figs. 9 and 10) showed gradual degradation out to 1 x 1014 n/cm2, with good margin over the SMD limits. The sourcing and sinking output current (Figs. 11 and 12) showed good stability out to 1 x 1014 n/cm2. The positive and negative power supply current (Fig. 13) showed good stability out to 1 x 1014 n/cm2. The positive and negative slew rate (Figs. 14 and 15) and the rise and fall time (Figs. 16 and 17) showed good stability out to 1 x 1014 n/cm2. We conclude that the ISL70227SEH is capable of post 1 x 1013 n/cm2 operation with selected parametric relaxations, mostly in the input bias current specification. The part is not capable of post 1 x 1014 n/cm2 operation as some parameters were outside the limits; the part did, however, remain functional. 6: Appendices 6.1: Reported parameters. Fig. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Parameter Limit, low Limit, high Units -110 -25 -25 -25 60.0 60.0 110 110 115 115 10.0 10.0 +110 +25 +25 +25 - µV nA nA nA dB dB dB dB dB dB mA mA -7.4 2.0 2.0 100.0 100.0 +7.4 - mA V/µs V/µs ns ns Input offset voltage Positive input bias current Negative input bias current Input offset current Positive open-loop gain Negative open-loop gain Positive power supply rejection ratio Negative power supply rejection ratio Positive common-mode rejection ratio Positive common-mode rejection ratio Output current, sourcing Output current, sinking Positive and negative power supply current Positive slew rate Negative slew rate Positive rise time Negative rise time 7: Document revision history Revision 0 Date 3 November 2013 Pages All Comments Original issue 8 Notes