PIC32MX170F512L-I/PF View Datasheet(PDF) - Microchip Technology

Part Name

Description

MFG CO.

PIC32MX170F512L-I/PF

32-bit Microcontrollers (up to 512 KB Flash and 64 KB SRAM) with Audio/Graphics/Touch (HMI), CAN, USB, and Advanced Analog

Microchip Technology 

PIC32MX1XX/2XX/5XX 64/100-PIN FAMILY

2.0 GUIDELINES FOR GETTING

STARTED WITH 32-BIT MCUS

Note:

This data sheet summarizes the features

of the PIC32MX1XX/2XX/5XX 64/100-pin

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

(www.microchip.com/PIC32).

2.1 Basic Connection Requirements

Getting started with the PIC32MX1XX/2XX/5XX 64/

100-pin 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 VDD and VSS pins (see 2.2 “Decoupling

Capacitors”)

• All AVDD and AVSS pins, even if the ADC module is

not used (see 2.2 “Decoupling Capacitors”)

• VCAP pin (see 2.3 “Capacitor on Internal Voltage

Regulator (VCAP)”)

• MCLR pin (see 2.4 “Master Clear (MCLR) Pin”)

• PGECx/PGEDx pins, used for In-Circuit Serial

Programming (ICSP™) and debugging purposes

(see 2.5 “ICSP Pins”)

• OSC1 and OSC2 pins, when external oscillator

source is used (see 2.7 “External Oscillator Pins”)

The following pins may be required:

VREF+/VREF- pins, used when external voltage

reference for the ADC module is implemented.

Note:

The AVDD and AVSS pins must be

connected, regardless of ADC use and

the ADC voltage reference source.

2.2 Decoupling Capacitors

The use of decoupling capacitors on power supply

pins, such as VDD, VSS, AVDD and AVSS is required.

See Figure 2-1.

Consider the following criteria when using decoupling

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

frequency 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.

• 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.

• 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.

 2014-2017 Microchip Technology Inc.

DS60001290E-page 25

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