Datasheet

AD7225
Rev. C | Page 16 of 24
AC REFERENCE SIGNAL
In some applications, it may be desirable to have ac reference
signals. The AD7225 has multiplying capability within the
upper (V
DD
− 4 V) and lower (2 V) limits of reference voltage
when operated with dual supplies. Therefore, ac signals need to
be ac-coupled and biased up before being applied to the
reference inputs. Figure 19 shows a sine wave signal applied to
V
REF
A. For input signal frequencies up to 50 kHz, the output
distortion typically remains less than 0.1%. The typical 3 dB
bandwidth figure for small signal inputs is 800 kHz.
*DIGITAL INPUTS OMITTED FOR CLARITY.
V
DD
V
SS
AGND DGND
V
OUT
A
DAC A
AD7225*
V
REF
A
+15V
+15V
15kΩ
10kΩ
+4V
–4V
REFERENCE
INPUT
00986-019
Figure 19. Applying an AC Signal to the AD7225