mc68hc705v12 Freescale Semiconductor, Inc, mc68hc705v12 Datasheet - Page 36

• Manufacturer Part Number: mc68hc705v12
• Description: M68hc05-based Mcu Hc05 Freescale Semiconductor
• Manufacturer: Freescale Semiconductor, Inc

General Description
1.9.1 V
1.9.2 V
Advance Information
DD
CCA
to V
to V
POOR ANALOG GROUNDING
SSD
SSA
GND
AIN
SHIELDED
CABLE
— MCU Internal Digital Power Decoupling
— Analog Subsystem Power Supply Pins
decoupling network. A frequency that is too low will reduce decoupling
effectiveness and could increase radiated RF emissions from the
system. A low value capacitor (470 pF to 0.01 F) placed in parallel with
the other capacitors will improve the bandwidth and effectiveness of the
network.
Decouple with a 0.1 F ceramic or polystyrene cap. If the self-resonance
frequency of the decoupling circuit (assume 4 nH per bond wire) is too
low, add a 0.01 F or smaller cap in parallel to increase the bandwidth
of the decoupling network. Place the smaller cap closest to the V
V
These pins are internally isolated from the digital V
The V
portions of the gauge subsystem. The analog supply pins should be
appropriately filtered to prevent any external noise affecting the analog
subsystems. The V
ground at a single point which has a low (HF) impedance to ground to
prevent common mode noise problems. If this is not practical, then the
V
return current is impeded from passing through the analog input ground
reference as shown in
SSD
SSA
Freescale Semiconductor, Inc.
Figure 1-5. Single-Sided PCB Example
For More Information On This Product,
PCB traces should be routed in such a manner that digital ground
pins.
SSA
pin provides a ground return for the A/D subsystem and
TO SYSTEM GND
Go to: www.freescale.com
V
ANX
SSA
General Description
V12
SSA
V
SSD
Figure
pin should be brought together with the digital
1-5.
AGND
GND
AIN
SHIELDED CABLE
BETTER ANALOG GROUNDING
MC68HC705V12
DD
V
ANX
SSA
and V
V12
V
SS
SSD
supplies.
—
DD
Rev. 3.0
and