link to page 17 link to page 10 link to page 14 link to page 14 Data SheetAD7817/AD7818Parameter AVersion1 BVersion1 SVersion1 UnitTestConditions/Comments POWER REQUIREMENTS (AD7818 ONLY)6 VDD 5.5 V max For specified performance 2.7 V min IDD Logic inputs = 0 V or VDD Normal Operation 2 mA max 1.3 mA typical Using External Reference 1.75 mA max 2.5 V internal reference connected Power-Down (VDD = 5 V) 10.75 μA max 6 μA typ Power-Down (VDD = 3 V) 4.5 μA max 2 μA typ Auto Power-Down Mode VDD = 3 V 10 SPS Throughput Rate 6.4 μW typ See the Power vs. Throughput section for description of power dissipation 1 kSPS Throughput Rate 48.8 μW typ in auto power-down mode 10 kSPS Throughput Rate 434 μW typ Power-Down 13.5 μW max Typically 6 μW ANALOG INPUTS (AD7817/AD7818)7 Input Voltage Range VREF VREF VREF V max 0 0 0 V min Input Leakage ±1 ±1 ±1 μA min Input Capacitance 10 10 10 pF max LOGIC INPUTS (AD7817/AD7818)4 Input High Voltage, VINH 2.4 2.4 2.4 V min VDD = 5 V ±10% Input Low Voltage, VINL 0.8 0.8 0.8 V max VDD = 5 V ±10% Input High Voltage, VINH 2 2 2 V min VDD = 3 V ±10% Input Low Voltage, VINL 0.4 0.4 0.4 V max VDD = 3 V ±10% Input Current, IIN ±3 ±3 ±3 μA max Typically 10 nA, VIN = 0 V to VDD Input Capacitance, CIN 10 10 10 pF max LOGIC OUTPUTS (AD7817/AD7818)4 Output High Voltage, VOH ISOURCE = 200 μA 4 4 4 V min VDD = 5 V ± 10% 2.4 2.4 2.4 V min VDD = 3 V ± 10% Output Low Voltage, VOL ISINK = 200 μA 0.4 0.4 0.4 V max VDD = 5 V ± 10% 0.2 0.2 0.2 V max VDD = 3 V ± 10% High Impedance Leakage Current ±1 ±1 ±1 μA max High Impedance Capacitance 15 15 15 pF max 1 The B Version and the S Version only apply to the AD7817. The A Version applies to the AD7817 or the AD7818 (as stated in specification). 2 See Terminology. 3 The accuracy of the temperature sensor is affected by reference tolerance. The relationship between the two is explained in the Temperature Measurement Error Due to Reference Error section. 4 Sample tested during initial release and after any redesign or process change that may affect this parameter. 5 On-chip reference shuts down when external reference is applied. 6 These specifications are typical for AD7818 at temperatures above 85°C and with VDD greater than 3.6 V. 7 This refers to the input current when the part is not converting. Primarily due to the reverse leakage current in the ESD protection diodes. Rev. E | Page 5 of 20 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAMS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TERMINOLOGY CONTROL BYTE Address Register Overtemperature Register CIRCUIT INFORMATION CONVERTER DETAILS TYPICAL CONNECTION DIAGRAM ANALOG INPUTS Analog Input DC Acquisition Time AC Acquisition Time ON-CHIP REFERENCE ADC TRANSFER FUNCTION TEMPERATURE MEASUREMENT TEMPERATURE MEASUREMENT ERROR DUE TO REFERENCE ERROR SELF-HEATING CONSIDERATIONS OPERATING MODES Mode 1 Mode 2 POWER vs. THROUGHPUT AD7817 SERIAL INTERFACE Read Operation Write Operation Simplifying the Serial Interface AD7818 SERIAL INTERFACE MODE Read Operation Write Operation OUTLINE DIMENSIONS ORDERING GUIDE