Question: The VDE Viorm = 1250 Vpeak reinforced isolation rating for the AD7403 is much higher than the CSA reinforced rating of 415 Vrms (586 Vpeak). Why is this the case? Answer: Different regulatory bodies such as VDE and CSA have different criteria for rating isolation. In the case of CSA their rating is dominated by the device creepage and clearance specification, >8.3mm. It should be noted however that the isolation rating that CSA give is based on devices with a Material Group III for a pollution degree of 2 for altitudes <2000m. This is standard practice in CSA to rate all parts to these criteria. CSA have however qualified the AD7403 package to have a CTI of ≥600 V. This means the AD7403 is qualified as a Material Group I device. Devices with a Material Group I for a pollution degree 2 for altitudes <2000m with a 8.3mm creepage and clearance specification can have a 830 Vrms reinforced working voltage. See the Safety and Regulatory Compliance Information page, http://www.analog.com/en/interface-isolation/digital-isolators/products/quality-assurance/cu_qa_isolators_safety_certificates/resources/fca.html for a record of all Analog Devices certification reports in relation to our iCoupler products.

Why has the power consumption of the AD7403 increased when compared to the AD7401A? 17mA typical at 20MHz and Vdd1 = 5.5V for the AD7401A and 42mA typical for the same conditions for the AD7403

Question: Why has the power consumption of the AD7403 increased when compared to the AD7401A? 17mA typical at 20MHz and Vdd1 = 5.5V for the AD7401A and 42mA typical for the same conditions for the AD7403 Answer: There are a few factors to consider that leads to the increased current consumption. The AC and DC performance of the AD7403 is much better in the AD7403 when compared to the AD7401A. For example the minimum SINAD for the AD7401A is 72dB however the AD7403 has a much improved SINAD of 81dB min. To achieve this level of improvement the AD7403 modulator uses more current. Secondly, the AD7403 also has much better regulatory approved isolation ratings. The Viorm of the AD7401A is 891 Vpeak while the AD7403 achieves an improved Viorm of 1250 Vpeak. In order to improve on the isolation specifications and enhance the robustness of the transmission across the isolation barrier there is more current used. However due to the improved accuracy of the AD7403 smaller shunt resistors can be used while maintaining the same level of ADC accuracy as that of the AD7401A. This should help reduce the power losses through the shunt and improve the overall system efficiency. If the same shunt resistor value is used ADC accuracy is improved and therefore it is possible to improve the overall system efficiency.

What is the difference between performance range and full scale range of the AD7403?

The performance specifications listed in the data sheet are for a +/-250mV input signal. If this input signal range is exceeded the AD7403 will continue to operate but the specifications are not guaranteed. So to maintain accuracy it is recommended to keep the input signals into the specified performance range. The maximum full scale positive input where the modulator will output all 1's is +320mV. The maximum full scale negative input where the modulator will output all 0's is -320mV.

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AD7403 Recommended for New Designs
The AD7403 is a high performance, second-order, S-? modulator that converts an analog input signal into a high speed, single-bit data stream, with on-chip...
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Table of Contents

+Documents
+General: FAQ
+AD1139: FAQ
+AD7091R Conversion Result Change
+AD1556: FAQ
+AD1580: FAQ
+AD1582: FAQ
+AD2S1200: FAQ
+AD2S1205: FAQ
+AD2S1210: FAQ
+AD2S75: FAQ
+AD2S80: FAQ
+AD2S80A: FAQ
+AD2S82A: FAQ
+AD2S83: FAQ
+AD2S90: FAQ
+AD2S99: FAQ
+AD4110-1: FAQ
+AD411x: FAQ
+AD5940: FAQ
+AD598: FAQ
+AD650: FAQ
+AD652: FAQ
+AD654: FAQ
+AD7091: FAQ
+AD7091R-X: FAQ
+AD711: FAQ
+AD7124-4: FAQ
+AD7124-8: FAQ
+AD7134: FAQ
+AD713: FAQ
+AD7142: FAQ
+AD7147: FAQ
+AD7148: FAQ
+AD7150: FAQ
+AD7151: FAQ
+AD7175-2: FAQ
+AD7176-2: FAQ
+AD7176: FAQ
+AD717x: FAQ
+AD7190: FAQ
+AD7192: FAQ
+AD7193: FAQ
+AD7195: FAQ
+AD719x: FAQ
+AD7265: FAQ
+AD7266: FAQ
+AD7280: FAQ
+AD7291: FAQ
+AD7298: FAQ
+AD7305: FAQ
+AD7321: FAQ
+AD7323: FAQ
+AD7328: FAQ
+AD7366-5: FAQ
+AD7367: FAQ
+AD736ARZ: FAQ
+AD737: FAQ
+AD738x : FAQ
+AD7398: FAQ
+AD7400A: FAQ
+AD7401: FAQ
-AD7403: FAQ
+AD74111: FAQ
+AD7415: FAQ
+AD7416: FAQ
+AD7417: FAQ
+AD7418: FAQ
+AD7450: FAQ
+AD7475: FAQ
+AD7484: FAQ
+AD7490: FAQ
+AD7492: FAQ
+AD75019: FAQ
+AD7503: FAQ
+AD7541A: FAQ
+AD7546: FAQ
AD7547: FAQ
+AD7568: FAQ
+AD7578: FAQ
+AD7606-4: FAQ
+AD7606: FAQ
+AD7606B: FAQ
+AD7606C: FAQ
+AD7608: FAQ
+AD7616 FAQ
+AD7616-P: FAQ
+AD7621: FAQ
+AD7625: FAQ
+AD7626: FAQ
+AD7631: FAQ
+AD7653: FAQ
+AD7654: FAQ
+AD7655: FAQ
+AD7656: FAQ
+AD7657-1: FAQ
+AD7663: FAQ
+AD7674: FAQ
+AD7675: FAQ
+AD7678: FAQ
+AD7682: FAQ
+AD7683: FAQ
+AD7684: FAQ
+AD7685: FAQ
+AD7688: FAQ
+AD7689: FAQ
+AD7690: FAQ
+AD7691: FAQ
+AD7705: FAQ
+AD7706: FAQ
+AD7707: FAQ
+AD7708: FAQ
+AD7709: FAQ
+AD7710: FAQ
+AD7711A: FAQ
+AD7712: FAQ
+AD7713: FAQ
+AD7714: FAQ
+AD7714YN: FAQ
+AD7715: FAQ
+AD7716: FAQ
+AD7718: FAQ
+AD7719: FAQ
+AD7720: FAQ
+AD7722: FAQ
+AD7725: FAQ
+AD7730: FAQ
+AD7731: FAQ
+AD7732: FAQ
+AD7738: FAQ
+AD7740: FAQ
+AD7741: FAQ
+AD7745: FAQ
+AD7746: FAQ
+AD7747: FAQ
+AD7760: FAQ
+AD7763: FAQ
+AD7766: FAQ
+AD7768: FAQ
+AD777x: FAQ
+AD7780: FAQ
+AD7785: FAQ
+AD7787: FAQ
+AD7788: FAQ
+AD7790: FAQ
+AD7792: FAQ
+AD7793: FAQ
+AD7794: FAQ
+AD7795: FAQ
+AD7798: FAQ
+AD7799: FAQ
+AD7805: FAQ
+AD7808: FAQ
+AD7809: FAQ
+AD780: FAQ
+AD7811: FAQ
+AD7812: FAQ
+AD7817: FAQ
+AD7819: FAQ
+AD7821: FAQ
+AD7825: FAQ
+AD7829: FAQ
+AD7835: FAQ
+AD7849: FAQ
+AD7851: FAQ
+AD7854: FAQ
+AD7856: FAQ
+AD7858: FAQ
+AD7859: FAQ
+AD7864: FAQ
+AD7865 : FAQ
+AD7872: FAQ
+AD7874: FAQ
+AD7879: FAQ
+AD7887: FAQ
+AD7888: FAQ
+AD7891-1: FAQ
+AD7891: FAQ
+AD7893-2: FAQ
+AD7895: FAQ
+AD7896: FAQ
+AD7899: FAQ
+AD7912: FAQ
+AD7921: FAQ
+AD7924: FAQ
+AD7927: FAQ
+AD7938: FAQ
+AD7942: FAQ
+AD7949: FAQ
+AD7960: FAQ
+AD7961: FAQ
+AD797: FAQ
+AD7980: FAQ
+AD7982: FAQ
+AD7984: FAQ
+AD7986: FAQ
+AD7988-1: FAQ
+AD7993: FAQ
+AD7994: FAQ
+AD7997: FAQ
+AD7998: FAQ
+ADA2200: FAQ
+ADAS1000: FAQ
+ADAS3022: FAQ
+ADAS3023: FAQ
+ADC: FAQ
+ADVFC32: FAQ
+EVAL-AD7719-EB: FAQ
+EVAL-ADAS3022EDZ: FAQ
+RDC1740: FAQ
+AD4030-24: FAQ
+AD4114: FAQ
+AD4116: FAQ
+AD4130-8 FAQ
+AD4131-8: FAQ
+AD4134 FAQ
+AD4170: FAQ
+AD4858
+AD674BBD: FAQ
+AD7172-2: FAQ
+AD7175-8: FAQ
+AD7191: FAQ
AD73360: FAQ
+AD73360AR: FAQ
+AD73360L: FAQ
+AD7357: FAQ
+AD7386-4: FAQ
+AD738x-4: FAQ
AD7398 SPI Voltage vs VCC
+AD7457: FAQ
+AD7606C-16: FAQ
+AD7609: FAQ
+AD7656-1: FAQ
AD7660: FAQ
+AD7665: FAQ
+AD7680: FAQ
+AD7686: FAQ
+AD7764: FAQ
+AD7778: FAQ
AD7892: FAQ
+AD7980SRMZ-EP: FAQ
+AD7991: FAQ
+AD9243: FAQ
+AD9260: FAQ
+AD9261: FAQ
+AD9262: FAQ
+AD974: FAQ
+AD976A: FAQ
+AD977A: FAQ
+ADAQ4003: FAQ
+ADAQ7768-1: FAQ
+ADAQ8092 FAQ
+DC590, DC2026, QuikEval: FAQs
+EVAL-AD7768-4FMCZ: FAQ
+Legacy LTC - Sigma Delta ADCs FAQ
+LTC2408: FAQ
+LTC2497: FAQ
+MAX1028: FAQ
+MAX1036: FAQ
+MAX1037EKA+: FAQ
+MAX11040GUU+: FAQ
+MAX11043: FAQ
+MAX11045: FAQ
+MAX11046 16-BIT AD: FAQ
+MAX11048: FAQ
+MAX11100EUB+: FAQ
+MAX11101: FAQ
+MAX11103: FAQ
+MAX11108: FAQ
MAX11125: FAQ
+MAX11125ATI+: FAQ
+MAX11130: FAQ
+MAX11131ATI+: FAQ
+MAX11136ATI+: FAQ
+MAX11150EVKIT#: FAQ
+MAX11154: FAQ
MAX11156: FAQ
+MAX11156ETC+: FAQ
+MAX11158: FAQ
+MAX11163: FAQ
+MAX11168EUB+: FAQ
+MAX11169EUB+: FAQ
+MAX11190: FAQ
+MAX11190ATE+: FAQ
MAX11192: FAQ
+MAX11192EVKIT#: FAQ
+MAX11200: FAQ
+MAX11200EEE+: FAQ
+MAX11201: FAQ
+MAX11203EEE+: FAQ
+MAX11206: FAQ
+MAX11207EEE+: FAQ
MAX11210: FAQ
+MAX11210EEE+: FAQ
+MAX11213EEE+T: FAQ
MAX11214: FAQ
MAX11214EUG+: FAQ
+MAX11214EUG+_T1: FAQ
+MAX11216: FAQ
+MAX11254ATJ+: FAQ
+MAX11254EVKIT#: FAQ
+MAX11259AWX+T: FAQ
+MAX11259PMB#: FAQ
+MAX11261BOB#: FAQ
+MAX11261ENX+: FAQ
+MAX11270EUG+: FAQ
+MAX11337ATJ+: FAQ
+MAX11410ATI+: FAQ
+MAX11608: FAQ
+MAX11609EEE+: FAQ
+MAX11612EUA+: FAQ
+MAX11612EVSYS: FAQ
+MAX11614EEE+: FAQ
+MAX11615EEE+C78: FAQ
+MAX11615EWE+: FAQ
+MAX11616EEE+: FAQ
+MAX11617EWE+: FAQ
+MAX11625: FAQ
+MAX11629EEE+: FAQ
+MAX11645EWC+T: FAQ
+MAX11647EUA+: FAQ
+MAX11900: FAQ
MAX11905: FAQ
+MAX11905EVKIT#: FAQ
+MAX1202AEAP+: FAQ
+MAX1220: FAQ
+MAX1229: FAQ
+MAX1230BCEG+: FAQ
+MAX1231AEEG+: FAQ
+MAX1239EEE+: FAQ
+MAX1239KEEE+: FAQ
+MAX1239LEEE+: FAQ
+MAX1258: FAQ
+MAX1271ACNG+: FAQ
MAX1300: FAQ
+MAX1300BEUG+: FAQ
+MAX1301AEUP+: FAQ
+MAX13171: FAQ
+MAX13204EALT+: FAQ
MAX1343: FAQ
+MAX1343BETX+: FAQ
+MAX13487: FAQ
+MAX13488: FAQ
+MAX1379ATP+: FAQ
+MAX1383: FAQ
+MAX1447ECJ+: FAQ
MAX14571: FAQ
+MAX14571EUD+: FAQ
MAX14574EWL+: FAQ
+MAX14574EWL+T: FAQ
+MAX14578: FAQ
+MAX14579EEVKIT#: FAQ
+MAX14588ETE+T: FAQ
+MAX145ACPA+: FAQ
+MAX1474: FAQ
+MAX14783: FAQ
+MAX14805: FAQ
+MAX14807ECB+: FAQ
+MAX14900D: FAQ
+MAX15090BEWI+: FAQ
+MAX1645AEEI+: FAQ
+MAX16600GGN+: FAQ
+MAX17823AGCB+: FAQ
MAX17823AGCB/V+: FAQ
+MAX17823AGCB/V+T: FAQ
+MAX17823GCB+: FAQ
+MAX182BEWI+T: FAQ
+MAX19777AZA+: FAQ
+MAX31865: FAQ
+MAX31865AAP+: FAQ
+Precision Technology Learning Modules
Programming FMC FRU ID EEPROM on Linux

AD7403: FAQ

Q: Why has the power consumption of the AD7403 increased when compared to the AD7401A? 17mA typical at 20MHz and Vdd1 = 5.5V for the AD7401A and 42mA typical for the same conditions for the AD7403

Question: Why has the power consumption of the AD7403 increased when compared to the AD7401A? 17mA typical at 20MHz and Vdd1 = 5.5V for the AD7401A and 42mA typical for the same conditions for the AD7403 Answer: There are a few factors to consider that leads to the increased current consumption. The AC and DC performance of the AD7403 is much better in the AD7403 when compared to the AD7401A. For example the minimum SINAD for the AD7401A is 72dB however the AD7403 has a much improved SINAD of 81dB min. To achieve this level of improvement the AD7403 modulator uses more current. Secondly, the AD7403 also has much better regulatory approved isolation ratings. The Viorm of the AD7401A is 891 Vpeak while the AD7403 achieves an improved Viorm of 1250 Vpeak. In order to improve on the isolation specifications and enhance the robustness of the transmission across the isolation barrier there is more current used. However due to the improved accuracy of the AD7403 smaller shunt resistors can be used while maintaining the same level of ADC accuracy as that of the AD7401A. This should help reduce the power losses through the shunt and improve the overall system efficiency. If the same shunt resistor value is used ADC accuracy is improved and therefore it is possible to improve the overall system efficiency.

Q: What is the difference between performance range and full scale range of the AD7403?

The performance specifications listed in the data sheet are for a +/-250mV input signal. If this input signal range is exceeded the AD7403 will continue to operate but the specifications are not guaranteed. So to maintain accuracy it is recommended to keep the input signals into the specified performance range. The maximum full scale positive input where the modulator will output all 1's is +320mV. The maximum full scale negative input where the modulator will output all 0's is -320mV.