Microchip Technology MCU PIC PIC18F87K22-I/PTRSL TQFP-80 MCP PIC18F87K22-I/PTRSL Data Sheet
Product codes
PIC18F87K22-I/PTRSL
2009-2011 Microchip Technology Inc.
DS39960D-page 39
PIC18F87K22 FAMILY
2.4
Voltage Regulator Pins (ENVREG
and V
and V
CAP
/V
DDCORE
)
The on-chip voltage regulator enable pin, ENVREG,
must always be connected directly to either a supply
voltage or to ground. Tying ENVREG to V
must always be connected directly to either a supply
voltage or to ground. Tying ENVREG to V
DD
enables
the regulator, while tying it to ground disables the
regulator. Refer to
regulator. Refer to
for details on connecting and using the
on-chip regulator.
When the regulator is enabled, a low-ESR (< 5Ω)
capacitor is required on the V
When the regulator is enabled, a low-ESR (< 5Ω)
capacitor is required on the V
CAP
/V
DDCORE
pin to
stabilize the voltage regulator output voltage. The
V
V
CAP
/V
DDCORE
pin must not be connected to V
DD
and
must use a capacitor of 10 µF connected to ground. The
type can be ceramic or tantalum. Suitable examples of
capacitors are shown in
type can be ceramic or tantalum. Suitable examples of
capacitors are shown in
. Capacitors with
equivalent specifications can be used.
Designers may use
Designers may use
to evaluate ESR
equivalence of candidate devices.
It is recommended that the trace length not exceed
0.25 inch (6 mm). Refer to
It is recommended that the trace length not exceed
0.25 inch (6 mm). Refer to
for additional information.
When the regulator is disabled, the V
CAP
/V
DDCORE
pin
must be tied to a voltage supply at the V
DDCORE
level.
Refer to
information on V
DD
and V
DDCORE
.
Some PIC18FXXKXX families, or some devices within
a family, do not provide the option of enabling or
disabling the on-chip voltage regulator:
• Some devices (with the name, PIC18LFXXKXX)
a family, do not provide the option of enabling or
disabling the on-chip voltage regulator:
• Some devices (with the name, PIC18LFXXKXX)
permanently disable the voltage regulator.
These devices do not have the ENVREG pin and
require a 0.1
These devices do not have the ENVREG pin and
require a 0.1
F capacitor on the V
CAP
/V
DDCORE
pin. The V
DD
level of these devices must comply
with the “voltage regulator disabled” specification
for Parameter D001, in
for Parameter D001, in
.
• Some devices permanently enable the voltage
regulator.
These devices also do not have the ENVREG pin.
The 10
These devices also do not have the ENVREG pin.
The 10
F capacitor is still required on the
V
CAP
/V
DDCORE
pin.
FIGURE 2-3:
FREQUENCY vs. ESR
PERFORMANCE FOR
SUGGESTED V
PERFORMANCE FOR
SUGGESTED V
CAP
.
10
1
0.1
0.01
0.001
0.01
0.1
1
10
100
1000 10,000
Frequency (MHz)
ESR (
)
Note:
Typical data measurement at 25°C, 0V DC bias.
TABLE 2-1:
SUITABLE CAPACITOR EQUIVALENTS
Make
Part #
Nominal
Capacitance
Base Tolerance
Rated Voltage
Temp. Range
TDK
C3216X7R1C106K
10 µF
±10%
16V
-55 to 125ºC
TDK
C3216X5R1C106K
10 µF
±10%
16V
-55 to 85ºC
Panasonic
ECJ-3YX1C106K
10 µF
±10%
16V
-55 to 125ºC
Panasonic
ECJ-4YB1C106K
10 µF
±10%
16V
-55 to 85ºC
Murata
GRM32DR71C106KA01L
10 µF
±10%
16V
-55 to 125ºC
Murata
GRM31CR61C106KC31L
10 µF
±10%
16V
-55 to 85ºC