Datasheet AD7988-1, AD7988-5 (Analog Devices) - 8

AD7988-1/AD7988-5 Data Sheet PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS REF 1 10 VIO VDD 2 AD7988-1/ 9 SDI AD7988-5 IN+ 3 8 SCK REF 1 10 VIO TOP VIEW VDD IN– 4 (Not to Scale) 7 SDO 2 AD7988-1/ 9 SDI AD7988-5 IN+ GND 5 3 8 SCK 6 CNV TOP VIEW IN– 4 7 SDO
4
(Not to Scale)
5 00 -00
GND
1-
5 6 CNV NOTES
231
1. THE EXPOSED PAD CAN BE CONNECTED TO GND.
23 10 10 Figure 4. 10-Lead MSOP Pin Configuration Figure 5. 10-Lead LFCSP Pin Configuration
Table 7. Pin Function Descriptions Pin No. Mnemonic Type1 Description
1 REF AI Reference Input Voltage. The VREF range is from 2.4 V to 5.1 V. It is referred to the GND pin. The GND pin should be decoupled closely to the REF pin with a 10 μF capacitor. 2 VDD P Power Supply. 3 IN+ AI Analog Input. It is referred to IN−. The voltage range, for example, the difference between IN+ and IN−, is 0 V to VREF. 4 IN− AI Analog Input Ground Sense. Connect to the analog ground plane or to a remote sense ground. 5 GND P Power Supply Ground. 6 CNV DI Convert Input. This input has multiple functions. On its leading edge, it initiates the conversions and selects the interface mode of the part: chain mode or CS mode. In CS mode, the SDO pin is enabled when CNV is low. In chain mode, the data should be read when CNV is high. 7 SDO DO Serial Data Output. The conversion result is output on this pin. It is synchronized to SCK. 8 SCK DI Serial Data Clock Input. When the part is selected, the conversion result is shifted out by this clock. 9 SDI DI Serial Data Input. This input provides multiple features. It selects the interface mode of the ADC as follows: Chain mode is selected if this pin is low during the CNV rising edge. In this mode, SDI is used as a data input to daisy-chain the conversion results of two or more ADCs onto a single SDO line. The digital data level on SDI is output on SDO with a delay of 16 SCK cycles. CS mode is selected if SDI is high during the CNV rising edge. In this mode, either SDI or CNV can enable the serial output signals when low. 10 VIO P Input/Output Interface Digital Power. Nominally at the same supply as the host interface (1.8 V, 2.5 V, 3 V, or 5 V). EP Exposed Pad. The exposed pad can be connected to GND. 1AI = analog input, DI = digital input, DO = digital output, and P = power. Rev. F | Page 8 of 23 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TYPICAL APPLICATION CIRCUIT TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TERMINOLOGY TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER OPERATION Transfer Functions TYPICAL CONNECTION DIAGRAM ANALOG INPUTS DRIVER AMPLIFIER CHOICE VOLTAGE REFERENCE INPUT POWER SUPPLY DIGITAL INTERFACE MODE, 3-WIRE MODE 4-WIRE CHAIN MODE APPLICATIONS INFORMATION INTERFACING TO BLACKFIN® DSP LAYOUT EVALUATING THE PERFORMANCE OF THE AD7988-1/AD7988-5 OUTLINE DIMENSIONS ORDERING GUIDE