THS10082

SLAS254B – MAY 2002 – REVISED NOVEMBER 2002

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32

10-Bit

ADC

VREFP

VREFM

AINP

Σ

VADC

AINM

+

–

Figure 41. Differential Input Stage

V

ADC +

ABS(AINP–AINM)

An advantage to single-ended operation is that the common-mode voltage

V

CM +

AINM

) AINP

2

can be rejected in the differential configuration, if the following condition for the analog input voltages is true:

AGND

v AINM, AINP v AV

DD

1V

v V

CM v

4V

In addition to the common-mode voltage rejection, the differential operation allows a dc-offset rejection which is common

to both analog inputs. See Figure 43.

SINGLE-ENDED MODE OF OPERATION

The THS10082 can be configured for single-ended operation using dc or ac coupling. In either case, the input of the

THS10082 must be driven from an operational amplifier that does not degrade the ADC performance. Because the

THS10082 operates from a 5-V single supply, it is necessary to level-shift ground-based bipolar signals to comply with its

input requirements. This can be achieved with dc and ac coupling. An application example is shown for dc-coupled level

shifting in the following section, dc coupling.

(2)

(3)

(4)

(5)