MCP3304 Microchip Technology, MCP3304 Datasheet - Page 21

• Manufacturer Part Number: MCP3304
• Description: 13-Bit Differential Input, Low Power A/D Converter with SPI Serial Interface
• Manufacturer: Microchip Technology

6.7
The MCP3302/04 devices provide both digital and ana-
log ground connections to provide another means of
noise reduction. As shown in Figure 6-11, the analog
and digital circuitry are separated internal to the device.
This reduces noise from the digital portion of the device
being coupled into the analog portion of the device. The
two grounds are connected internally through the sub-
strate which has a resistance of 5 -10 Ω.
If no ground plane is utilized, then both grounds must
be connected to V
available, both digital and analog ground pins should
be connected to the analog ground plane. If both an
analog and a digital ground plane are available, both
the digital and the analog ground pins should be con-
nected to the analog ground plane, as shown in
Figure 6-11. Following these steps will reduce the
amount of digital noise from the rest of the board being
coupled into the A/D Converter.
FIGURE 6-11:
Digital Ground Pins.
© 2007 Microchip Technology Inc.
Utilizing the Digital and Analog
Ground Pins
Digital Side
-SPI Interface
-Shift Register
-Control Logic
DGND
SS
Analog Ground Plane
on the board. If a ground plane is
MCP3302/04
Substrate
V
5 - 10 Ω
Separation of Analog and
DD
Analog Side
-Sample Cap
-Capacitor Array
-Comparator
AGND
0.1 µF
MCP3302/04
DS21697C-page 21