ꢉꢃ ꢠꢡ ꢢ ꢣ ꢤ
www.ti.com
SBAS341B − DECEMBER 2004 − REVISED APRIL 2005
ground, as shown in Figure 53. Each main supply bus
should also be bypassed with a bank of capacitors from
47µF to 0.1µF, as shown.
The I/O and digital supplies (IOVDD and DVDD) can be
connected together when using the same voltage. In this
case, only one bank of 47µF to 0.1µF capacitors is needed
on the main supply bus, though each supply pin must still
be bypassed with a 1µF and 0.1µF ceramic capacitor.
POWER SUPPLIES
Three supplies are used on the ADS1602: analog (AVDD),
digital (DVDD) and digital I/O (IOVDD). Each supply must
be suitably bypassed to achieve the best performance. It
is recommended that a 1µF and 0.1µF ceramic capacitor
be placed as close to each supply pin as possible. Connect
each supply-pin bypass capacitor to the associated
DVDD
µ
µ
µ
1 F
µ
0.1 F
47 F
4.7 F
IOVDD
AVDD
µ
µ
1 F
47 F
µ
µ
0.1 F
4.7 F
CP
CP
CP
µ
µ
0.1 F
4.7 F
µ
47 F
µ
1 F
42
41
55
38
37
34
33
1
DGND 36
AGND
AVDD
CP
2
3
If using separate analog and
digital ground planes, connect
together on the ADS1602 PCB.
6
AGND
CP
AVDD
AGND
7
9
ADS1602
DGND
AGND
µ
µ
0.1 F
NOTE: CP = 1 F
CP
AVDD
AGND
10
11
CP
12
AVDD
15
10k
18
19
22
23
CP
CP
Ω
Figure 53. Recommended Power-Supply Bypassing
22
BB [ BURR-BROWN CORPORATION ]
