Microchip Technology DV320032 Data Sheet
2012-2013 Microchip Technology Inc.
DS60001185C-page 27
PIC32MX330/350/370/430/450/470
2.0
GUIDELINES FOR GETTING
STARTED WITH 32-BIT MCUS
STARTED WITH 32-BIT MCUS
2.1
Basic Connection Requirements
Getting started with the PIC32MX330/350/370/430/
450/470 family of 32-bit Microcontrollers (MCUs)
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
450/470 family of 32-bit Microcontrollers (MCUs)
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
)
• All AV
DD
and AV
SS
pins, even if the ADC module is
not used (see
)
• V
CAP
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
)
The following pins may be required:
V
REF
+/V
REF
- pins, used when external voltage
reference for the ADC module is implemented.
2.2
Decoupling Capacitors
The use of decoupling capacitors on power supply
pins, such as V
pins, such as V
DD
, V
SS
, AV
DD
and AV
SS
is required.
See
Consider the following criteria when using decoupling
capacitors:
• Value and type of capacitor: A value of 0.1 µF
capacitors:
• Value and type of capacitor: A value of 0.1 µF
(100 nF), 10-20V is recommended. The capacitor
should be a low Equivalent Series Resistance
(low-ESR) capacitor and have resonance fre-
quency in the range of 20 MHz and higher. It is
further recommended that ceramic capacitors be
used.
should be a low Equivalent Series Resistance
(low-ESR) capacitor and have resonance fre-
quency in the range of 20 MHz and higher. It is
further 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 that
the capacitors be placed 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.
to the pins as possible. It is recommended that
the capacitors be placed 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.
• Handling high frequency noise: If the board is
experiencing high frequency noise, upward of
tens of MHz, add a second ceramic-type capaci-
tor 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 capaci-
tor 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 PIC32MX330/350/370/430/450/
470 family of devices. It is not intended to
be a comprehensive reference source.
To complement the information in this
data sheet, refer to the related section of
the “PIC32 Family Reference Manual”,
which is available from the Microchip
web site (
470 family of devices. It is not intended to
be a comprehensive reference source.
To complement the information in this
data sheet, refer to the related section of
the “PIC32 Family Reference Manual”,
which is available from the Microchip
web site (
).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
Note:
The AV
DD
and AV
SS
pins must be
connected, regardless of ADC use and
the ADC voltage reference source.
the ADC voltage reference source.