Total dose testing of the HS-565BRH digital to analog converter Nick van Vonno Intersil Corporation Revision 0 August 2010 Table of Contents 1. 2. 3. 4. 5 6 7 8 9 Introduction Reference Documents Part Description Test Description 4.1 Irradiation facility 4.2 Test fixturing 4.3 Characterization equipment and procedures 4.4 Experimental Matrix 4.5 Downpoints Results 5.1 Test results 5.2 Variables data Discussion Conclusion Appendices Document revision history 1 1. Introduction This report summarizes the results of a low and high dose rate total dose test of the HS565BRH digital to analog converter. The test was conducted in order to determine the sensitivity of the part to the total dose environment and to low dose rate irradiation in particular. 2. Reference Documents • • • • MIL-STD-883G test method 1019.7 MIL-PRF-38535 (QML) HS-565BRH data sheet, Intersil document FN4607.3 DSCC Standard Microcircuit Drawing (SMD) 5962- 96755 3: Part Description The HS-565BRH is a hardened 12-bit analog to digital converter (DAC). The part replaces the HS565ARH which is obsolete and no longer available. The monolithic chip includes a precision voltage reference, a thin-film resistor R-2R ladder network, a reference control amplifier and twelve high-speed bipolar current switches. The part is implemented in a dielectrically isolated process which provides latchupfree operation and minimizes parasitic capacitance and leakage currents. Ground currents are also minimized, which produces a low and constant current through the ground terminal, reducing errors due to code-dependent ground currents. The HS-565BRH is laser trimmed at the die level for a maximum integral nonlinearity error of +/-0.25LSB at room temperature. In addition, the low noise on-chip buried Zener diode reference is trimmed both for absolute value and minimum temperature coefficient. Detailed specifications for the part are contained in SMD 5962-96755. The Intersil Web site contains a link for downloading this drawing. • QML Qualified per MIL-PRF-38535 requirements • 100 krad (Si) total dose rating • DAC and reference on a single chip • Pin compatible with AD-565A and HI-565A • Settles to 0.50 LSB in 500ns maximum • Monotonicity guaranteed over temperature • 0.50 LSB Maximum nonlinearity guaranteed over temperature o • Low gain drift 50ppm/ C (maximum, DAC plus reference) • ±0.75 LSB accuracy guaranteed over temperature 2 Figure 1: HS-565BRH block diagram. 4: Test Description 4.1 Irradiation Facilities 60 High dose rate testing of the HS-565BRH was performed using a Gammacell 220 Co irradiator located in the Palm Bay, Florida Intersil facility. Low dose rate testing was performed on a subcontract basis at White Sands Missile Range (White Sands, NM). The use of an off-site irradiator necessitated detailed precautions to control the packing temperature during shipment to avoid annealing effects. This was accomplished by the use of Styrofoam shipping containers, Gelpack cold packs and miniaturized strip chart recorders to provide a continuous temperature monitor. The high dose rate irradiations were done at 55rad(Si)/s and the low dose rate work was performed at .010rad(Si)/s, both per MIL-STD-883 Method 1019.7. Dosimetry for both tests was performed using Far West Technology radiochromic dosimeters and on-site readout equipment. 4.2 Test Fixturing Figure 2 shows the configuration used for biased irradiation in conformance with Standard Microcircuit Drawing (SMD) 5962-96755. This configuration was used for both low and high dose rate irradiation. The unbiased irradiation was carried out with all pins grounded. 3 Figure 2: Irradiation bias configuration for the HS-565BRH per Standard Microcircuit Drawing (SMD) 5962-96755, as used for both low and high dose rate biased irradiation. 4.3 Characterization equipment and procedures All electrical testing was performed outside the irradiator using the production automated test equipment (ATE) with datalogging of all parameters at each downpoint. Downpoint electrical testing was performed at room temperature. 4 4.5 Experimental matrix The experimental matrix consisted of four cells: five samples irradiated at high dose rate with all pins grounded, five samples irradiated at high dose rate under bias, five samples irradiated at low dose rate with all pins grounded and five samples irradiated at low dose rate under bias. One control unit was used. This experimental approach was in close compliance with the guidelines of MIL-STD-883 Test Method 1019.7 for diagnostic ELDRS testing. Samples of the HS-565BRH were drawn from wafer 12 of production lot DPE8AK and were packaged in the standard hermetic 24-pin ceramic flatpack (CFP) production package. Samples were processed through the standard burnin cycle before irradiation, as required by MIL-STD-883, and were screened to the SMD 5962-96755 limits at room, low and high temperatures before the test. 4.6 Downpoints Downpoints for the tests were zero, 50krad(Si), 100krad(Si) and 150krad(Si) for the high dose rate test and zero, 10krad(Si), 25krad(Si), 50krad(Si), 100krad(Si), 125krad(Si) and 150krad(Si) for the low dose rate test. 5: Results 5.1 Test results The low and high dose rate tests of the HS-565BRH are complete and showed no reject devices after irradiation to 150krad(Si) at low and high dose rate), screening to the SMD post-irradiation limits. 5.2 Variables data The plots in Figures 3 through 26 show data at all downpoints. The plots show the median of key parameters as a function of total dose for each of the four irradiation conditions. We chose to plot the median (as opposed to for example mean and standard deviation) because of the relatively small sample sizes involved. All parts showed good stability over irradiation, with no observed low dose rate sensitivity. Appendix 1 summarizes key parameters of the device that have been plotted in Figures 3 – 26. Terminology is in accordance with the applicable SMD 5962-96755. Refer to the Discussion section for further analysis. 5 Positive supply current, mA 10.0 8.0 6.0 High dose rate, unbiased 4.0 High dose rate, biased Low dose rate, unbiased 2.0 Low dose rate, biased 0.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 3: HS-565BRH positive power supply current as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is 11.8mA maximum post-irradiation. -0.5 High dose rate, unbiased Negative supply current, mA -2.5 High dose rate, biased Low dose rate, unbiased -4.5 Low dose rate, biased -6.5 -8.5 -10.5 -12.5 -14.5 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 4: HS-565BRH negative power supply current as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -14.5mA maximum post-irradiation. 6 10.100 10.080 Reference output, V 10.060 10.040 10.020 10.000 9.980 High dose rate, unbiased 9.960 High dose rate, biased Low dose rate, unbiased 9.940 Low dose rate, biased 9.920 9.900 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 5: HS-565BRH voltage reference output voltage as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are 9.9V to 10.1V post-irradiation. -1.60 Unipolar output current, mA -1.70 -1.80 -1.90 -2.00 -2.10 High dose rate, unbiased High dose rate, biased -2.20 Low dose rate, unbiased -2.30 Low dose rate, biased -2.40 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 6: HS-565BRH unipolar output current as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are -2.4mA to -1.6mA post-irradiation. 7 -0.80 Bipolar output current, mA -0.85 -0.90 -0.95 -1.00 -1.05 High dose rate, unbiased High dose rate, biased -1.10 Low dose rate, unbiased -1.15 Low dose rate, biased -1.20 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 7: HS-565BRH bipolar output current as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are -1.2mA to -0.8mA post-irradiation. Unipolar output offset error, % of FS 0.05 0.04 High dose rate, unbiased 0.03 High dose rate, biased Low dose rate, unbiased 0.02 Low dose rate, biased 0.01 0.00 -0.01 -0.02 -0.03 -0.04 -0.05 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 8: HS-565BRH unipolar output offset error as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are -0.05% of full scale to 0.05% of full scale post-irradiation. 8 0.25 Bipolar output offset error, % of FS 0.20 High dose rate, unbiased High dose rate, biased 0.15 Low dose rate, unbiased 0.10 Low dose rate, biased 0.05 0.00 -0.05 -0.10 -0.15 -0.20 -0.25 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 9: HS-565BRH bipolar output offset error as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are -0.25% of full scale to 0.25% of full scale post-irradiation. Unipolar full scale error, % of FS 0.75 0.55 0.35 0.15 -0.05 -0.25 High dose rate, unbiased High dose rate, biased -0.45 Low dose rate, unbiased -0.65 Low dose rate, biased -0.85 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 10: HS-565BRH unipolar full scale error as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limits for this parameter are -0.85% of full scale to 0.85% of full scale post-irradiation. 9 Bipolar full scale error, % of FS 0.75 0.55 0.35 0.15 -0.05 -0.25 High dose rate, unbiased High dose rate, biased -0.45 Low dose rate, unbiased -0.65 Low dose rate, biased -0.85 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 11: HS-565BRH bipolar full scale error as a function of total dose irradiation at low and high dose rate. The low dose rate was 0.01rad(Si)/s and the high dose rate was 55rad(Si)/s. The SMD limits for this parameter are -0.85% of full scale to 0.85% of full scale post-irradiation. 0.25 Bipolar zero error, % of FS 0.20 0.15 0.10 0.05 0.00 -0.05 High dose rate, unbiased -0.10 High dose rate, biased -0.15 Low dose rate, unbiased -0.20 Low dose rate, biased -0.25 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 12: HS-565BRH bipolar zero error as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, unbiased irradiation. The SMD limits for this parameter are -0.25% of full scale to 0.25% of full scale post-irradiation. 10 Digital input LOW current, bit 1, µA 0 -5 -10 -15 -20 -25 High dose rate, unbiased High dose rate, biased -30 Low dose rate, unbiased -35 Low dose rate, biased -40 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 13: HS-565BRH digital input LOW current, bit 1, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is -40µA maximum post-irradiation. Digital input LOW current, bit 6, µA 0 -5 -10 -15 -20 -25 High dose rate, unbiased High dose rate, biased -30 Low dose rate, unbiased -35 Low dose rate, biased -40 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 14: HS-565BRH digital input LOW current, bit 6, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is -40µA maximum post-irradiation. 11 Digital input LOW current, bit 12, µA 0 -5 -10 -15 -20 -25 High dose rate, unbiased High dose rate, biased -30 Low dose rate, unbiased -35 Low dose rate, biased -40 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 15: HS-565BRH digital input LOW current, bit 12, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is -40µA maximum post-irradiation. Digital input HIGH current, bit 1, µA 1.0 0.9 High dose rate, unbiased 0.8 High dose rate, biased Low dose rate, unbiased 0.7 Low dose rate, biased 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 16: HS-565BRH digital input HIGH current, bit 1, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is 1µA maximum post-irradiation. All four curves are coincident with the X-axis. 12 Digital input HIGH current, bit 6, µA 1.0 0.9 High dose rate, unbiased 0.8 High dose rate, biased Low dose rate, unbiased 0.7 Low dose rate, biased 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 17: HS-565BRH digital input HIGH current, bit 6, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is 1µA maximum post-irradiation. All four curves are coincident with the X-axis. Digital input HIGH current, bit 12, µA 1.0 0.9 High dose rate, unbiased High dose rate, biased 0.8 Low dose rate, unbiased 0.7 Low dose rate, biased 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 18: HS-565BRH digital input HIGH current, bit 12, as a function of total dose irradiation at low dose rate of 0.01rad(Si)/s, biased irradiation. The SMD limit for this parameter is 1µA maximum post-irradiation. All four curves are coincident with the X-axis. 13 Positive power supply gain sensitivity, ppm of full scale/%∆VCC 10 9 High dose rate, unbiased 8 High dose rate, biased Low dose rate, unbiased 7 Low dose rate, biased 6 5 4 3 2 1 0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 19: HS-565BRH positive power supply gain sensitivity as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is 10 ppm of full scale/%∆Vcc maximum post-irradiation. Negative power supply gain sensitivity, ppm of full scale/%∆VEE 25 High dose rate, unbiased High dose rate, biased 20 Low dose rate, unbiased Low dose rate, biased 15 10 5 0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 20: HS-565BRH negative power supply gain sensitivity as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is 25 ppm of full scale/%∆Vcc maximum post-irradiation. 14 1.0 High dose rate, unbiased Integral nonlinearity, bit 1, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 21: HS-565BRH integral nonlinearity, bit 1, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 1.0 High dose rate, unbiased Integral nonlinearity, bit 6, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 22: HS-565BRH integral nonlinearity, bit 6, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 15 1.0 High dose rate, unbiased Integral nonlinearity, bit 12, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 23: HS-565BRH integral nonlinearity, bit 12, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 1.0 High dose rate, unbiased Differential nonlinearity, bit 1, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 24: HS-565BRH differential nonlinearity, bit 1, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 16 1.0 High dose rate, unbiased Differential nonlinearity, bit 6, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 25: HS-565BRH differential nonlinearity, bit 6, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 1.0 High dose rate, unbiased Differential nonlinearity, bit 12, LSB 0.8 High dose rate, biased 0.6 Low dose rate, unbiased 0.4 Low dose rate, biased 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 0 25 50 75 100 125 150 Total dose, krad(Si) Figure 26: HS-565BRH differential nonlinearity, bit 12, as a function of total dose irradiation at low and high dose rate. The low dose rate was .01rad(Si)/s and the high dose rate was 55rad(Si)/s. Sample size for each cell was 5. The SMD limit for this parameter is -1LSB to 1LSB post-irradiation. 17 6: Discussion ATE characterization of the samples at all downpoints showed no rejects tot the SMD post-irradiation limits. The data is plotted in figures 3 to 26 and showed good stability over total dose irradiation. The HS565BRH displayed moderate low dose rate sensitivity in the reference voltage, bipolar output offset error, unipolar full scale error and bipolar full scale error parameters. The worst-case values encountered for these parameters were well within the applicable post-irradiation SMD limits. All other plotted parameters show little and sometimes no difference between the high and low dose rate response. Accordingly, the part is considered moderately low dose rate sensitive up to the 100krad(Si) data sheet total dose rating. No bias sensitivity was noted. 7: Conclusion This document reports the results of a total dose test of the HS-565BRH 12-bit digital to analog converter (DAC). Samples were tested under biased and unbiased conditions to a maximum total dose of 150krad(Si) at high and low dose rate. The HS-565BRH displayed moderate low dose rate sensitivity, notably in the reference voltage, bipolar output offset error, unipolar full scale error and bipolar full scale error parameters. The worst-case values encountered for these parameters were well within the applicable post-irradiation SMD limits. Accordingly, the part is considered moderately low dose rate sensitive up to the 100krad(Si) data sheet total dose rating. No differences between biased and unbiased irradiation were noted, and the part is not considered bias sensitive. 18 7: Appendices Appendix 1: Plotted parameters and limits. Parameter Symbol Positive supply current Negative supply current Reference voltage Unipolar output current Bipolar output current Unipolar output offset error Bipolar output offset error Unipolar full scale error Bipolar full scale error Bipolar zero error Digital input LOW current, bit 1 Digital input LOW current, bit 6 Digital input LOW current, bit 12 Digital input HIGH current, bit 1 Digital input HIGH current, bit 6 Digital input HIGH current, bit 12 Positive power supply gain sensitivity Negative power supply gain sensitivity Integral nonlinearity, bit 1 Integral nonlinearity, bit 6 Integral nonlinearity, bit 12 Differential nonlinearity, bit 1 Differential nonlinearity, bit 6 Differential nonlinearity, bit 12 Limits minimum ICC IEE VREF_OUT IOUT1 IOUT2 VOS BPOE AE BPAE BPZE IIL1 IIL6 IIL12 IIH1 IIH6 IIH12 +PSS -PSS ILE1 ILE6 ILE12 DLE1 DLE6 DLE12 9.9 -2.4 -1.2 -0.05 -0.05 -0.85 -0.85 -0.25 -1 -1 -1 -1 -1 -1 +11.8 -14.5 10.1 -1.6 -0.8 +0.05 +0.05 +0.85 +0.85 +0.25 -40 -40 -40 1 1 1 10 25 +1 +1 +1 +1 +1 +1 Note 1: Units for these two parameters are ppm of full scale/%∆Vcc. 8: Document revision history Revision 0 Date August 2010 Pages All Comments Original issue 19 Units Figure mA mA V mA mA % FS % FS % FS % FS % FS µA µA µA µA µA µA Note 1 Note 1 LSB LSB LSB LSB LSB LSB 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 maximum