 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
AD7982 Datasheet(PDF) 19 Page - Analog Devices |
|
||||||||||||||||||||||||||||||
AD7982 Datasheet(HTML) 19 Page - Analog Devices |
|
|
19 / 26 page 
AD7982 Data Sheet Rev. D | Page 18 of 25 CS MODE, 3-WIRE WITHOUT BUSY INDICATOR CS mode, 3-wire without busy indicator is usually used when a single AD7982 is connected to an SPI-compatible digital host. The connection diagram is shown in Figure 29, and the corresponding timing is given in Figure 30. With SDI tied to VIO, a rising edge on CNV initiates a conversion, selects the CS mode, and forces SDO to high impedance. After a conversion is initiated, it continues until completion irrespective of the state of CNV. This feature can be useful, for instance, to bring CNV low to select other SPI devices, such as analog multiplexers; however, CNV must be returned high before the minimum conversion time elapses and then held high for the maximum possible conversion time to avoid the generation of the busy signal indicator. When the conversion completes, the AD7982 enters the acquisition phase and powers down. When CNV goes low, the MSB is output onto SDO. The remaining data bits are clocked by subsequent SCK falling edges. The data is valid on both SCK edges. Although the rising edge can capture the data, a digital host using the SCK falling edge allows a faster reading rate, provided it has an acceptable hold time. After the 18th SCK falling edge or when CNV goes high (whichever occurs first), SDO returns to high impedance. AD7982 SDI SDO CNV SCK CONVERT DATA IN CLK DIGITAL HOST VIO Figure 29. CS Mode, 3-Wire Without Busy Indicator Connection Diagram (SDI High) SDO D17 D16 D15 D1 D0 tDIS SCK 12 3 16 17 18 tSCK tSCKL tSCKH tHSDO tDSDO CNV CONVERSION ACQUISITION tCONV tCYC ACQUISITION SDI = 1 tCNVH tACQ tEN Figure 30. CS Mode, 3-Wire Without Busy Indicator Serial Interface Timing (SDI High) |
|
English ▼
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
