Data SheetAD7091RPIN CONFIGURATION AND FUNCTION DESCRIPTIONSV1DD10 VDRIVEREF2IN/REFOUTAD7091R9 SDOV3INTOP VIEW8 SCLK(Not to Scale)REGCAP 47 CSGND 56 CONVSTVDD 110 VDRIVEREFIN/REFOUT 29 SDOAD7091RNOTES38TOP VIEWSCLK1. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY.VINFOR INCREASED RELIABILITY OF THE SOLDER JOINTS ANDREGCAP 4(Not to Scale)7 CS 003 FOR MAXIMUM THERMAL CAPABILITY, SOLDER THE EXPOSED 004 GND 56 CONVSTPAD TO THE SUBSTRATE, GND. 0494- 1 0494- 1 Figure 3. Pin Configuration, 10-Lead LFCSP Figure 4. Pin Configuration, 10-Lead MSOP Table 5. Pin Function DescriptionsPin No.LFCSP MSOPMnemonic Description 1 1 VDD Power Supply Input. The VDD range is from 2.7 V to 5.25 V. This supply pin should be decoupled to GND. The typical recommended values are 10 μF and 0.1 μF. 2 2 REFIN/REFOUT Voltage Reference Input Output. Decouple this pin to GND. The typical recommended decoupling capacitor value is 2.2 μF. The user can either access the internal 2.5 V reference or overdrive the internal reference with an externally applied voltage. The reference voltage range for an externally applied reference is 2.7 V to VDD. 3 3 VIN Analog Input. The single-ended analog input range is from 0 V to VREF. 4 4 REGCAP Decoupling Capacitor Pin for Voltage Output from Internal Regulator. This output pin should be decoupled separately to GND using a 1 μF capacitor. The voltage at this pin is 1.8 V typical. 5 5 GND Analog Ground. This pin is the ground reference point for all circuitry on the AD7091R. The analog input signal should be referred to this GND voltage. 6 6 CONVST Convert Start. Active low edge triggered logic input. The falling edge of CONVST places the track- and-hold into hold mode and initiates a conversion. 7 7 CS Chip Select. Active low logic input. The serial bus is enabled when CS is held low, and in this mode CS is used to frame the output data on the SPI bus. 8 8 SCLK Serial Clock. This pin acts as the serial clock input. 9 9 SDO Serial Data Output. The conversion output data is supplied to this pin as a serial data stream. The bits are clocked out on the falling edge of the SCLK input. The data is provided MSB first. 10 10 VDRIVE Logic Power Supply Input. The voltage supplied at this pin determines the operating voltage of the interface. Decoupling capacitors should be connected between VDRIVE and GND. The typical recommended values are 10 μF and 0.1 μF. The voltage range of this pin is 1.65 V to 5.25 V. 11 N/A EPAD Exposed Pad. The exposed pad is not connected internally. For increased reliability of the solder joints and for maximum thermal capability, solder the exposed pad to the substrate, GND. Rev. B | Page 7 of 20 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER OPERATION ADC TRANSFER FUNCTION INTERNAL/EXTERNAL VOLTAGE REFERENCE TYPICAL CONNECTION DIAGRAM ANALOG INPUT MODES OF OPERATION Normal Mode Power-Down Mode POWER CONSUMPTION Normal Mode Normal and Power-Down Mode Combination SERIAL INTERFACE WITH BUSY INDICATOR WITHOUT BUSY INDICATOR SOFTWARE RESET INTERFACING WITH 8-/16-BIT SPI OUTLINE DIMENSIONS ORDERING GUIDE