MC3PHAC Motorola, MC3PHAC Datasheet - Page 19

• Manufacturer Part Number: MC3PHAC
• Description: 3-Phase AC Motor Controller
• Manufacturer: Motorola

Digital Power Supply Bypassing
Analog Power Supply Bypassing
MOTOROLA
V
Fast signal transitions connected internally on these pins place high, short-
duration current demands on the power supply. To prevent noise problems,
take special care to provide power supply bypassing at the V
Place the bypass capacitors as close as possible to the MC3PHAC. Use a high-
frequency-response ceramic capacitor, such as a 0.1 F, paralleled with a bulk
capacitor in the range of 1 F to 10 F for bypassing the digital power supply.
V
generator and analog-to-digital converter (ADC). On the schematics in this
document, analog ground is labeled with an A and other grounds are digital
grounds. Analog power is labeled as +5 A. It is good practice to isolate the
analog and digital +5 volt power supplies by using a small inductor or a low
value resistor less than 5 ohms in series with the digital power supply, to create
the +5 A supply. ADC V
voltage reference.
Decoupling of these pins should be per the digital power supply bypassing,
described previously. ADC V
together and connected to the same potential as V
DD
DDA
Freescale Semiconductor, Inc.
and V
For More Information On This Product,
and V
ACCELERATION INPUT
SS
Figure 7. Deceleration as a Function of Bus Voltage
SSA
3-Phase AC Motor Controller
Go to: www.freescale.com
are the digital power supply and ground pins for the MC3PHAC.
are the power supply pins for the analog portion of the clock
IN PC MASTER SOFTWARE MODE)
BEGIN MODERATING DECEL
(LEVEL IS PROGRAMMABLE
REF
is the power supply pin used for setting the ADC’s
REF
(pin 1) and V
DDA
(pin 3) shall be connected
DD
.
Digital Power Supply Bypassing
BUS VOLTAGE
DD
and V
MC3PHAC/D
SS
pins.
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