MCP3204 Microchip Technology, MCP3204 Datasheet - Page 18

• Manufacturer Part Number: MCP3204
• Description: 2.7V 4-Channel/8-Channel 12-Bit A/D Converters with SPI Serial Interface
• Manufacturer: Microchip Technology

MCP3204/3208
6.5
The MCP3204/3208 devices provide both digital and
analog ground connections to provide another means
of noise reduction. As shown in Figure 6-5, the analog
and digital circuitry is 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 .
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. Following these
steps will reduce the amount of digital noise from the
rest of the board being coupled into the A/D Converter.
FIGURE 6-5:
Ground Pins.
DS21298B-page 18
Digital Side
-SPI Interface
-Shift Register
-Control Logic
Ground Pin
Utilizing the Digital and Analog
Ground Pins
Digital
Separation of Analog and Digital
SS
on the board. If a ground plane is
Substrate
5 - 10
V
Analog Side
-Sample Cap
-Capacitor Array
-Comparator
DD
Ground Pin
Analog
Preliminary
1999 Microchip Technology Inc.