PIC24EP256GU810-I Datasheet, PDF (32/622 Pages) Electronic Film Capacitors, Inc. – 16-Bit Microcontrollers and Digital Signal Controllers with High-Speed PWM, USB and Advanced Analog

dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814
FIGURE 2-1:
RECOMMENDED
MINIMUM CONNECTION
VDD
10 µF
Tantalum
0.1 µF
Ceramic
R
R1
MCLR
C
VSS
VUSB3V3⁽¹⁾
dsPIC33EP/
PIC24EP
VDD
0.1 µF
VDD
Ceramic
VSS
0.1 µF
Ceramic
L1⁽²⁾
0.1 µF
Ceramic
0.1 µF
Ceramic
Note 1:
2:
If the USB module is not used, VUSB3V3 must be
connected to VDD, as shown.
As an option, instead of a hard-wired connection, an
inductor (L1) can be substituted between VDD and
AVDD to improve ADC noise rejection. The inductor
impedance should be less than 1 and the inductor
capacity greater than 10 mA.
Where:
f = ^F-----^C-2--^N----^V-
(i.e., ADC conversion rate/2)
f = -----------1------------
2 LC
L
=


^---2---^----f^1------C^-----
2
2.2.1
TANK CAPACITORS
On boards with power traces running longer than six
inches in length, it is suggested to use a tank capacitor
for integrated circuits including DSCs to supply a local
power source. The value of the tank capacitor should
be determined based on the trace resistance that con-
nects the power supply source to the device and the
maximum current drawn by the device in the applica-
tion. In other words, select the tank capacitor so that it
meets the acceptable voltage sag at the device. Typical
values range from 4.7 µF to 47 µF.
2.3 CPU Logic Filter Capacitor
Connection (VCAP)
A low-ESR (< 1 Ohms) capacitor is required on the
VCAP pin, which is used to stabilize the voltage
regulator output voltage. The VCAP pin must not be
connected to VDD and must have a capacitor greater
than 4.7 µF (10 µF is recommended), 16V connected
to ground. The type can be ceramic or tantalum. See
Section 32.0 “Electrical Characteristics” for
additional information.
The placement of this capacitor should be close to the
VCAP. It is recommended that the trace length not
exceeds one-quarter inch (6 mm). See Section 29.2
“On-Chip Voltage Regulator” for details.
2.4 Master Clear (MCLR) Pin
The MCLR pin provides two specific device
functions:
• Device Reset
• Device Programming and Debugging
During device programming and debugging, the
resistance and capacitance that can be added to the
pin must be considered. Device programmers and
debuggers drive the MCLR pin. Consequently,
specific voltage levels (VIH and VIL) and fast signal
transitions must not be adversely affected. Therefore,
specific values of R and C will need to be adjusted
based on the application and PCB requirements.
For example, as shown in Figure 2-2, it is
recommended that the capacitor C, be isolated from
the MCLR pin during programming and debugging
operations.
Place the components as shown in Figure 2-2 within
one-quarter inch (6 mm) from the MCLR pin.
FIGURE 2-2:
EXAMPLE OF MCLR PIN
CONNECTIONS
VDD
R⁽¹⁾
R1⁽²⁾
MCLR
JP
dsPIC33EP
C
Note 1:
2:
R  10 k is recommended. A suggested
starting value is 10 k. Ensure that the
MCLR pin VIH and VIL specifications are met.
R1  470 will limit any current flowing into
MCLR from the external capacitor C, in the
event of MCLR pin breakdown, due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS). Ensure that the MCLR pin
VIH and VIL specifications are met.
DS70616G-page 32
 2009-2012 Microchip Technology Inc.