MMC2114 MOTOROLA [Motorola, Inc], MMC2114 Datasheet - Page 516

• Manufacturer Part Number: MMC2114
• Description: M CORE Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Queued Analog-to-Digital Converter (QADC)
Advance Information
516
PCB
NOTE:
Figure 19-49. Star-Ground at the Point of Power Supply Origin
+5 V
ANALOG POWER SUPPLY
Two similar approaches to improving or eliminating the problems
associated with grounding excess transient currents involve star-point
ground systems. One approach is to star-point the different grounds at
the power supply origin, thus keeping the ground isolated. Refer to
Figure
Another approach is to star-point the different grounds near the analog
ground pin on the microcontroller by using small traces for connecting
the non-analog grounds to the analog ground. The small traces are
meant only to accommodate dc differences, not ac transients.
This star-point scheme still requires adequate grounding for digital and
analog subsystems in addition to the star-point ground.
Freescale Semiconductor, Inc.
AGND
QADC
For More Information On This Product,
Queued Analog-to-Digital Converter (QADC)
19-49.
Go to: www.freescale.com
+5 V
V
V
SS
DD
MMC2114 • MMC2113 • MMC2112 — Rev. 1.0
DIGITAL POWER SUPPLY
PGND
+5 V
MOTOROLA