Microchip Technology TDGL003 - chipKIT Max32 Development Board TDGL003 TDGL003 Data Sheet
Product codes
TDGL003
PIC32MX3XX/4XX
DS61143H-page 32
© 2011 Microchip Technology Inc.
FIGURE 2-1:
RECOMMENDED
MINIMUM CONNECTION
MINIMUM CONNECTION
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
/V
CORE
)
2.3.1
INTERNAL REGULATOR MODE
A low-ESR (< 1 Ohm) capacitor is required on the
V
V
CAP
/V
CORE
pin, which is used to stabilize the internal
voltage regulator output. The V
CAP
/V
CORE
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
can be ceramic or tantalum. Refer to
for additional information
on C
EFC
specifications. This mode is enabled by
connecting the ENVREG pin to V
DD
.
2.3.2
EXTERNAL REGULATOR MODE
In this mode the core voltage is supplied externally
through the V
through the V
CORE
/V
CAP
pin. A low-ESR capacitor of
10 µF is recommended on the V
CAP
/V
CORE
pin. This
mode is enabled by grounding the ENVREG pin.
The placement of this capacitor should be close to the
V
V
CAP
/V
CORE
. It is recommended that the trace length
not exceed one-quarter inch (6 mm). Refer to
for
details.
2.4
Master Clear (MCLR) Pin
The MCLR pin provides for two specific device
functions:
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.
of R and C will need to be adjusted based on the
application and PCB requirements.
, it is
recommended that the capacitor C, be isolated from
the MCLR pin during programming and debugging
operations.
the MCLR pin during programming and debugging
operations.
Place the components shown in
within
one-quarter inch (6 mm) from the MCLR pin.
FIGURE 2-2:
EXAMPLE OF MCLR PIN
CONNECTIONS
CONNECTIONS
PIC32MX
V
DD
V
SS
V
DD
V
SS
V
SS
V
DD
AV
DD
AV
SS
V
DD
V
SS
C
R
V
DD
MCLR
0.1 µF
Ceramic
Ceramic
V
CAP
/V
CO
RE
10
Ω
R1
C
BP
0.1 µF
Ceramic
C
Ceramic
C
BP
0.1 µF
Ceramic
C
Ceramic
C
BP
0.1 µF
Ceramic
C
Ceramic
C
BP
0.1 µF
Ceramic
C
Ceramic
C
BP
C
EFC
Note 1:
R
≤ 10 kΩ is recommended. A suggested start-
ing 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
PIC32MX
JP