aduc7062 Analog Devices, Inc., aduc7062 Datasheet - Page 96

• Manufacturer Part Number: aduc7062
• Description: Low-power, Precision Analog Microcontroller, Dual ?-? Adcs, Flash/ee, Arm7tdmi
• Manufacturer: Analog Devices, Inc.

ADuC7060/ADuC7061/ADuC7062
HARDWARE DESIGN CONSIDERATIONS
POWER SUPPLIES
The ADuC7060/ADuC7061/ADuC7062 operational power
supply voltage range is 2.375 V to 2.625 V. Separate analog and
digital power supply pins (AV
AV
present on the system DV
operate with split supplies, that is, it can use different voltage
levels for each supply. For example, the system can be designed
to operate with an DV
level can be at 2.5 V, or vice versa. A typical split supply
configuration is shown in Figure 23.
As an alternative to providing two separate power supplies, the
user can reduce noise on AV
and/or ferrite bead between AV
AV
shown in Figure 24. With this configuration, other analog circuitry
(such as op amps, voltage reference, and others) can be powered
from the AV
DD
DD
to be kept relatively free of noisy digital signals often
separately to ground. An example of this configuration is
DIGITAL
SUPPLY
+
–
0.1µF
DD
Figure 23. External Dual Supply Connections
10µF
supply line as well.
30
44
29
10
43
DD
9
DV
DGND
voltage level of 2.6 V while the AV
DD
ADuC7060
DD
line. In this mode, the part can also
DD
DD
DD
by placing a small series resistor
and DV
and DV
AGND
AV
DD
24
23
DD
DD
10µF
, and then decoupling
, respectively) allow
ANALOG
SUPPLY
0.1µF
+
–
Rev. PrA | Page 96 of 100
DD
Notice that in both Figure 23 and Figure 24, a large value (10 μF)
reservoir capacitor sits on DV
sits on AV
located at each AV
design practice, be sure to include all of these capacitors and ensure
the smaller capacitors are close to each AV
lengths as short as possible. Connect the ground terminal of
each of these capacitors directly to the underlying ground plane.
Note that the analog and digital ground pins on the ADuC7060/
ADuC7061/ADuC7062 must be referenced to the same system
ground reference point at all times.
Finally, note that once the DVDD supply reaches 1.8 V, it must
ramp to 2.25 V in less than 128 ms. This is a requirement of the
internal power-on-reset circuitry.
DIGITAL
SUPPLY
+
–
0.1µF
DD
. In addition, local small value (0.1 μF) capacitors are
Figure 24. External Single Supply Connections
10µF
DD
Preliminary Technical Data
and DV
30
44
29
10
43
9
DV
DGND
ADuC7060
DD
BEAD
DD
DD
pin of the chip. As per standard
, and a separate 10 μF capacitor
AGND
AV
DD
24
23
10µF
DD
ANALOG
SUPPLY
pin with trace
0.1µF