ADS-235 Datel, Inc., ADS-235 Datasheet - Page 5

• Manufacturer Part Number: ADS-235
• Description: Sampling A/D Converters
• Manufacturer: Datel, Inc.

rates above 0.5MHz in order to ensure proper performance of
the internal dynamic circuits.
Power Supplies and Grounding
The ADS-235, ADS-236 and ADS-237 have separate digital
and analog power supply pins and grounds (refer to the Input/
Output Connections table for pin numbers) to reduce digital
noise in the analog signal path. The digital data outputs also
have a separate supply pin, +DV
from either a 3.0V or 5.0V supply to allow the user the option
of interfacing with 3.0V logic.
separate low impedance paths for the analog and digital
The converters should be mounted on a board that provides
®
V
Figure 3.5 DC Coupled Single Ended Input
Figure 3.1 Analog Input Sample-and-Hold
V
Figure 3.3 DC Coupled Differential Input
DC
DC
V
V
V
DC
–V
IN
IN
Ø1
Ø1
+
–
IN
V
V
DC
V
IN
Ø2
IN
C
C
S
S
Ø1
®
Ø1
+ –
R
– +
R
R
S
C
C
2, which can be powered
H
H
Ø1
C
C
Ø1
V
10
9
V
8
10
9
8
OUT
OUT
–
+
V
V
V
V
V
V
IN
DC
IN
IN
DC
IN
+
–
+
–
Figure 3. Analog Input
5
supplies and grounds. For best performance the supplies used
should be clean, linear regulated supplies. All power supplies
should be bypassed to ground with a 10uF tantalum capacitor
in parallel with a 0.1uF ceramic capacitor. Locate the bypass
capacitors as close to the converter as possible. If the converter
is to be powered from one supply then the analog supply and
ground pins should be isolated with ferrite beads from the
digital supply and ground pins. See the Typical Connection
Diagram, Figure 4.
In order to minimize overall converter noise it is recommended
that the V
in parallel with a 0.01 uF ceramic capacitor. Locate the bypass
capacitors as close to the unit as possible.
+1.0<V
ADS-235, ADS-236, ADS-237
RIN
V
Figure 3.6 Differential Analog Input Common
Figure 3.4 AC Coupled Single Ended Input
V
DC
DC
DC
Figure 3.2 AC Coupled Differential Input
=+4.0V
pin be bypassed using a 4.7 uF tantalum capacitor
<+4.0V
=+1V
–V
V
IN
V
IN
V
IN
DC
Mode Voltage Range
V
V
V
R
IN
R
R
IN
IN
+
+
+
2.0Vp-p
2.0Vp-p
2.0Vp-p
10
9
10
9
8
8
V
V
V
V
V
V
V
V
V
IN
IN
IN
IN
DC
IN
IN
DC
IN
–
–
–
+
–
+
–
+5V
0V