EVAL-AD7934CB Analog Devices Inc, EVAL-AD7934CB Datasheet - Page 10

• Manufacturer Part Number: EVAL-AD7934CB
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7934CB

• Lead Free Status / Rohs Status: Not Compliant

AD7933/AD7934
Pin No.
20
21
22
23
24
25 to
28
Mnemonic
WR
RD
CS
AGND
V
V
REFIN
IN
0 to V
/V
REFOUT
IN
3
Description
Write Input. Active low logic input used in conjunction with CS to write data to the control register.
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 AD7933/AD7934. 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 this appears at this pin. It is recommended to decouple the
V
voltage range for the external reference is 0.1 V to V
exceed V
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 as four single-ended inputs, two fully differential pairs, or two pseudo
differential pairs by appropriately setting the MODE bits in the control register (see Table 10). Select the analog
input channel to be converted either by writing to Address Bit ADD1 and Address Bit ADD0 in the control register
prior to the conversion, or by using the on-chip sequencer. The input range for all input channels can either be 0 V
to V
and CODING bits in the control register. To avoid noise pickup, connect any unused input channels to AGND.
REFIN
REF
/V
or 0 V to 2 × V
REFOUT
DD
+ 0.3 V. See the Reference section.
pin to AGND with a 470 nF capacitor. This pin can be overdriven by an external reference. The input
REF
, and the coding can be binary or twos complement, depending on the states of the RANGE
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DD
; however, ensure that the analog input range does not