Microchip Technology MA330019-2 Data Sheet
© 2007-2012 Microchip Technology Inc.
DS70292G-page 19
dsPIC33FJ32GP302/304, dsPIC33FJ64GPX02/X04, AND dsPIC33FJ128GPX02/X04
2.0
GUIDELINES FOR GETTING
STARTED WITH 16-BIT
DIGITAL SIGNAL
CONTROLLERS
STARTED WITH 16-BIT
DIGITAL SIGNAL
CONTROLLERS
2.1
Basic Connection Requirements
Getting started with the dsPIC33FJ32GP302/304,
dsPIC33FJ64GPX02/X04, and dsPIC33FJ128GPX02/
X04 family of 16-bit Digital Signal Controllers (DSCs)
requires attention to a minimal set of device pin
connections before proceeding with development. The
following is a list of pin names, which must always be
connected:
• All V
dsPIC33FJ64GPX02/X04, and dsPIC33FJ128GPX02/
X04 family of 16-bit Digital Signal Controllers (DSCs)
requires attention to a minimal set of device pin
connections before proceeding with development. The
following is a list of pin names, which must always be
connected:
• All V
DD
and V
SS
pins
(see
• All AV
DD
and AV
SS
pins (regardless if ADC module
is not used)
(see
(see
• V
CAP
(see
)
• MCLR pin
(see
• PGECx/PGEDx pins used for In-Circuit Serial
Programming™ (ICSP™) and debugging purposes
(see
(see
)
• OSC1 and OSC2 pins when external oscillator
source is used
(see
(see
)
Additionally, the following pins may be required:
• V
• V
REF
+/V
REF
- pins used when external voltage
reference for ADC module is implemented
2.2
Decoupling Capacitors
The use of decoupling capacitors on every pair of
power supply pins, such as V
power supply pins, such as V
DD
, V
SS
, AV
DD
and
AV
SS
is required.
Consider the following criteria when using decoupling
capacitors:
• Value and type of capacitor: Recommendation
capacitors:
• Value and type of capacitor: Recommendation
of 0.1 µF (100 nF), 10-20V. This capacitor should
be a low-ESR and have resonance frequency in
the range of 20 MHz and higher. It is
recommended that ceramic capacitors be used.
be a low-ESR and have resonance frequency in
the range of 20 MHz and higher. It is
recommended that ceramic capacitors be used.
• Placement on the printed circuit board: The
decoupling capacitors should be placed as close
to the pins as possible. It is recommended to
place the capacitors on the same side of the
board as the device. If space is constricted, the
capacitor can be placed on another layer on the
PCB using a
to the pins as possible. It is recommended to
place the capacitors on the same side of the
board as the device. If space is constricted, the
capacitor can be placed on another layer on the
PCB using a
via; however, ensure that the trace
length from the pin to the capacitor is within
one-quarter inch (6 mm) in length.
one-quarter inch (6 mm) in length.
• Handling high frequency noise: If the board is
experiencing high frequency noise, upward of
tens of MHz, add a second ceramic-type capacitor
in parallel to the above described decoupling
capacitor. The value of the second capacitor can
be in the range of 0.01 µF to 0.001 µF. Place this
second capacitor next to the primary decoupling
capacitor. In high-speed circuit designs, consider
implementing a decade pair of capacitances as
close to the power and ground pins as possible.
For example, 0.1 µF in parallel with 0.001 µF.
tens of MHz, add a second ceramic-type capacitor
in parallel to the above described decoupling
capacitor. The value of the second capacitor can
be in the range of 0.01 µF to 0.001 µF. Place this
second capacitor next to the primary decoupling
capacitor. In high-speed circuit designs, consider
implementing a decade pair of capacitances as
close to the power and ground pins as possible.
For example, 0.1 µF in parallel with 0.001 µF.
• Maximizing performance: On the board layout
from the power supply circuit, run the power and
return traces to the decoupling capacitors first,
and then to the device pins. This ensures that the
decoupling capacitors are first in the power chain.
Equally important is to keep the trace length
between the capacitor and the power pins to a
minimum thereby reducing PCB track inductance.
return traces to the decoupling capacitors first,
and then to the device pins. This ensures that the
decoupling capacitors are first in the power chain.
Equally important is to keep the trace length
between the capacitor and the power pins to a
minimum thereby reducing PCB track inductance.
Note 1: This data sheet summarizes the features
of the dsPIC33FJ32GP302/304,
dsPIC33FJ64GPX02/X04, and
dsPIC33FJ128GPX02/X04 family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to the “dsPIC33F/PIC24H
Family Reference Manual”, which is
available from the Microchip website
(
dsPIC33FJ64GPX02/X04, and
dsPIC33FJ128GPX02/X04 family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to the “dsPIC33F/PIC24H
Family Reference Manual”, which is
available from the Microchip website
(
www.microchip.com
).
2: Some registers and associated bits
described in this section may not be avail-
able on all devices. Refer to
able on all devices. Refer to
in this data
sheet for device-specific register and bit
information.
information.
Note:
The AV
DD
and AV
SS
pins must be
connected independent of the ADC
voltage reference source.
voltage reference source.