AD7934-6(RevA) Ver la hoja de datos (PDF) - Analog Devices

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componentes Descripción

Fabricante

AD7934-6
(Rev.:RevA)

4-Channel, 625 kSPS, 12-Bit Parallel ADC with a Sequencer

Analog Devices 

AD7934-6

Pin No.

21

Mnemonic

RD

22

CS

23

AGND

24

VREFIN/VREFOUT

25 to 28 VIN0 to VIN3

Description

Read Input. Active low logic input used in conjunction with CS to access the conversion result. The conversion

result is placed on the data bus following the falling edge of RD read while CS is low.

Chip Select. Active low logic input used in conjunction with RD and WR to read conversion data or write data

to the control register.

Analog Ground. This is the ground reference point for all analog circuitry on the AD7934-6. All analog input

signals and any external reference signal should be referred to this AGND voltage. The AGND and DGND

voltages should ideally be at the same potential and must not be more than 0.3 V apart, even on a transient

basis.

Reference Input/Output. This pin is connected to the internal reference, and is the reference source for the

ADC. The nominal internal reference voltage is 2.5 V, and it appears at this pin. It is recommended that this pin

be decoupled to AGND with a 470 nF capacitor. This pin can be overdriven by an external reference. The input

voltage range for the external reference is 0.1 V to VDD; however, care must be taken to ensure that the analog

input range does not exceed VDD + 0.3 V. See the Reference Section.

Analog Input 0 to Analog Input 3. Four analog input channels that are multiplexed into the on-chip track-and-

hold. The analog inputs can be programmed to be four single-ended inputs, two fully differential pairs, or two

pseudo differential pairs by setting the MODE bits in the control register appropriately (see Table 9). The

analog input channel to be converted can be selected either by writing to the address bits (ADD1 and ADD0)

in the control register prior to the conversion, or by using the on-chip sequencer. The input range for all input

channels can be either 0 V to VREF, or 0 V to 2 × VREF, and the coding can be binary or twos complement,

depending on the states of the RANGE and CODING bits in the control register. Any unused input channels

should be connected to AGND to avoid noise pickup.

Rev. A | Page 8 of 28

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