Datasheet AD7656A (Analog Devices) - 8

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Data Sheet AD7656A PIN CONFIGURATION AND FUNCTION DESCRIPTIONS T S L DI E N/ S FOU E C B A E F L P AR/ /R RE /P CAP CAP CA ND ND ND ND ND ND R/ CC F F F FIN CC /S SE V E V DB15 W H SER A AG RE AG RE AG RE AG AG R A AG 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 DB14/REFBUF 1 48 V6 EN/DIS DB13 PIN 1 2 47 AVCC DB12 3 46 AVCC DB11 4 45 V5 DB10/DOUT C 5 44 AGND DB9/DOUT B 6 43 AGND AD7656A DB8/DOUT A 7 42 V4 TOP VIEW DGND 8 (Not to Scale) 41 AVCC V 9 40 AV DRIVE CC DB7/HBEN/DCEN 10 39 V3 DB6/SCLK 11 38 AGND DB5/DCIN A 12 37 AGND DB4/DCIN B 13 36 V2 DB3/DCIN C 14 35 AVCC DB2/SEL C 15 34 AVCC DB1/SEL B 16 33 V1 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 A Y C B A Y E L CS RD SS T T T B ND CC DD ND E V S S S W/B V S BUS ST DG DV ESET AG
003
NV NV NV RANG R DB0/ CO CO CO
11127- Figure 3. Pin Configuration
Table 5. Pin Function Descriptions1 Pin No. Mnemonic Description
1 DB14/REFBUFEN/DIS Data Bit 14/Reference Buffer Enable and Disable. When SER/PAR/SEL = 0, this pin acts as a three- state digital input/output pin. 2, 3, 64 DB13, DB12, DB15 Data Bit 13, Data Bit 12, and Data Bit 15. When SER/PAR/SEL = 0, these pins act as three-state parallel digital input/output pins. When CS and RD are low, these pins are used to output the conversion result. When CS and WR are low, these pins are used to write to the control register. When SER/PAR/SEL = 1, tie these pins to DGND. 4 DB11 Data Bit 11/Digital Ground. When SER/PAR/SEL = 0, this pin acts as a three-state parallel digital output pin. When SER/PAR/SEL = 1, tie this pin to DGND. 5 DB10/DOUT C Data Bit 10/Serial Data Output C. When SER/PAR/SEL = 0, this pin acts as a three-state parallel digital output pin. When SER/PAR/SEL = 1 and SEL C = 1, this pin takes on its DOUT C function and outputs serial conversion data. this pin configures the serial interface to have three DOUT x output lines. 6 DB9/DOUT B Data Bit 9/Serial Data Output B. When SER/PAR/SEL = 0, Pin 6 acts as a three-state parallel digital output pin. When SER/PAR/SEL = 1 and SEL B = 1, Pin 6 takes on its DOUT B function and outputs serial conversion data. this pin configures the serial interface to have two DOUT x output lines. 7 DB8/DOUT A Data Bit 8/Serial Data Output A. When SER/PAR/SEL = 0, this pin acts as a three-state parallel digital output pin. When SER/PAR/SEL = 1 and SEL A = 1, this pin takes on its DOUT A function and outputs serial conversion data. 8, 25 DGND Digital Ground. These pins are the ground reference point for al digital circuitry on the AD7656A. Connect both DGND pins to the DGND plane of a system. Ideally, the DGND and AGND voltages are at the same potential and must not be more than 0.3 V apart, even on a transient basis. 9 VDRIVE Logic Power Supply Input. The voltage supplied at this pin determines the operating voltage of the interface. Nominally, it is at the same supply as the supply of the host interface. Decouple this pin to DGND, and place 10 µF and 100 nF decoupling capacitors on the VDRIVE pin. Rev. 0 | Page 7 of 28 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS POWER SUPPLY SEQUENCING THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CONVERTER DETAILS Track-and-Hold Amplifiers Analog Input ADC TRANSFER FUNCTION REFERENCE SECTION TYPICAL CONNECTION DIAGRAM DRIVING THE ANALOG INPUTS INTERFACE SECTION Parallel Interface (SER/PAR/SEL = 0) SOFTWARE SELECTION OF ADCS Changing the Analog Input Range (H/S SEL = 0) Changing the Analog Input Range (H/S SEL = 1) Serial Interface (SER/PAR/SEL = 1) SERIAL READ OPERATION DAISY-CHAIN MODE (DCEN = 1, SER//SEL = 1) Standby/Partial Power-Down Modes of Operation (SER/PAR/SEL = 0 or SER/PAR/SEL = 1) APPLICATION HINTS LAYOUT OUTLINE DIMENSIONS ORDERING GUIDE