Getac Technology Corporation V110GD Manual De Usuario
PIC32MX1XX/2XX
DS61168C-page 28
Preliminary
© 2011 Microchip Technology Inc.
2.2.1
BULK CAPACITORS
The use of a bulk capacitor is recommended to improve
power supply stability. Typical values range from 4.7 µF
to 47 µF. This capacitor should be located as close to
the device as possible.
power supply stability. Typical values range from 4.7 µF
to 47 µF. This capacitor should be located as close to
the device as possible.
2.3
Capacitor on Internal Voltage
Regulator (V
Regulator (V
CAP
)
2.3.1
INTERNAL REGULATOR MODE
A low-ESR (1 ohm) capacitor is required on the V
CAP
pin, which is used to stabilize the internal voltage regu-
lator output. The V
lator output. The V
CAP
pin must not be connected to
V
DD
, and must have a C
EFC
capacitor, with at least a
6V rating, connected to ground. The type can be
ceramic or tantalum. Refer to
ceramic or tantalum. Refer to
for additional information on C
EFC
specifications.
2.4
Master Clear (MCLR) Pin
The MCLR pin provides for two specific device
functions:
• Device Reset
• Device programming and debugging
Pulling The MCLR pin low generates a device Reset.
functions:
• Device Reset
• Device programming and debugging
Pulling The MCLR pin low generates a device Reset.
illustrates a typical MCLR circuit. 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
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
IH
and V
IL
) 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 illustrated in
of R and C will need to be adjusted based on the
application and PCB requirements.
For example, as illustrated in
recommended that the capacitor C, be isolated from
the MCLR pin during programming and debugging
operations.
Place the components illustrated in
the MCLR pin during programming and debugging
operations.
Place the components illustrated in
within
one-quarter inch (6 mm) from the MCLR pin.
FIGURE 2-2:
EXAMPLE OF MCLR PIN
CONNECTIONS
CONNECTIONS
(1,2,3)
Note 1:
R
≤ 10 kΩ is recommended. A suggested
starting value is 10 k
Ω. Ensure that the MCLR
pin V
IH
and V
IL
specifications are met.
2:
R1
≤ 470Ω 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
V
event of MCLR pin breakdown, due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS). Ensure that the MCLR pin
V
IH
and V
IL
specifications are met.
3:
The capacitor can be sized to prevent uninten-
tional Resets from brief glitches or to extend
the device Reset period during POR.
tional Resets from brief glitches or to extend
the device Reset period during POR.
C
R1
R
V
DD
MCLR
PIC32
JP