dspic33fj128mc204 Microchip Technology Inc., dspic33fj128mc204 Datasheet - Page 22

• Manufacturer Part Number: dspic33fj128mc204
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

FIGURE 2-1:
2.2.1
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
A low-ESR (< 5 Ohms) capacitor is required on the
V
voltage regulator output voltage. The V
pin must not be connected to V
capacitor between 4.7 µF and 10 µF, 16V connected to
ground. The type can be ceramic or tantalum. Refer to
Section 31.0
additional information.
The placement of this capacitor should be close to the
V
length not exceed one-quarter inch (6 mm). Refer to
Section 28.2 “On-Chip Voltage Regulator” for
details.
DS70291C-page 20
CAP
CAP
Ceramic
V
0.1 µF
DD
R
/V
/V
C
DDCORE
DDCORE
R1
Capacitor on Internal Voltage
Regulator (V
TANK CAPACITORS
10 Ω
MCLR
V
V
SS
DD
. It is recommended that the trace
“Electrical
pin, which is used to stabilize the
RECOMMENDED
MINIMUM CONNECTION
dsPIC33F
CAP
Ceramic
0.1 µF
/V
Characteristics”
DD
DDCORE
, and must have a
V
V
CAP
DD
SS
Ceramic
0.1 µF
Ceramic
0.1 µF
)
/V
Ceramic
0.1 µF
DDCORE
Preliminary
for
2.4
The MCLR pin provides for 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 (V
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
recommended that the capacitor C, be isolated from
the MCLR pin during programming and debugging
operations.
Place the components shown in Figure 2-2 within
one-quarter inch (6 mm) from the MCLR pin.
FIGURE 2-2:
Note 1: R ≤ 10 kΩ is recommended. A suggested
example,
2: R1 ≤ 470Ω will limit any current flowing into
Master Clear (MCLR) Pin
starting value is 10 kΩ. Ensure that the
MCLR pin V
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
V
V
IH
DD
R
JP
C
and V
as
IL
shown
EXAMPLE OF MCLR PIN
CONNECTIONS
IH
specifications are met.
R1
© 2009 Microchip Technology Inc.
and V
IH
and V
IL
MCLR
in
specifications are met.
dsPIC33F
IL
Figure 2-2,
) and fast signal
it
is