Rainbow-electronics ADC10D020 Manual de usuario descargar pdf (Pagina 28)

Applications Information (Continued)

2.1 REFERENCE VOLTAGE

The reference voltage should be within the range specified in

the Operating Ratings table (0.8V to 1.5V). A reference

voltage that is too low could result in a noise performance

that is less than desired because the quantization level falls

below other noise sources. On the other hand, a reference

voltage that is too high means that an input signal that

produces a full scale output uses such a large input range

that the input stage is less linear, resulting in a degradation

of distortion performance. Also, for large reference voltages,

the internal ladder buffer runs out of head-room, leading to a

reduction of gain in that buffer and causing gain error deg-

radation.

The Reference bypass pins V

and V

are output com-

pensated and should each be bypassed with a parallel com-

bination ofa5µF(minimum) and 0.1 µF capacitors.

As mentioned in the previous section, the V

CMO

output can

be used as the ADC reference.

2.2 V

CMO

OUTPUT

The V

CMO

output pin is intended to provide a common mode

bias for the differential input pins of the ADC10D020. It can

also be used as a voltage reference source. Care should be

taken, however, to avoid loading this pin with more than 1

mA. A load greater than this could result in degraded long

term and temperature stability of this voltage. The V

CMO

is output compensated and should be bypassed with a

2 µF/0.1 µF combination, minimum. See

2.0 REFERENCE

INPUTS

for more information on using the V

CMO

output as a

reference source.

3.0 DIGITAL INPUT PINS

The seven digital input pins are used to control the function

of the ADC10D020.

20025574

FIGURE 7. The V

CMO

output pin may be used as an internal reference source if its output is divided down and not

loaded excessively.

ADC10D020

www.national.com 28

1 2 ... 23 24 25 26 27 28 29 30 31 32

Comentarios a estos manuales

Sin comentarios

Rainbow-electronics ADC10D020 Manual de usuario Pagina 28

Comentarios a estos manuales

Relacionado con productos y manuales para Sensores Rainbow-electronics ADC10D020