Datasheet

 2011 Microchip Technology Inc. DS39931D-page 31
PIC18F46J50 FAMILY
2.4 Voltage Regulator Pins
(V
CAP/VDDCORE)
On “F” devices, a low-ESR (< 5Ω) capacitor is required
on the V
CAP/VDDCORE pin to stabilize the voltage
regulator output voltage. The V
CAP/VDDCORE pin must
not be connected to V
DD or any other voltage source on
an “F” device. The V
CAP/VDDCORE pin should only be
connected to a 10 µF capacitor to ground. The type can
be ceramic or tantalum. Suitable example capacitors
are provided in Table 2-1.
Designers may use Figure 2-3 to evaluate ESR
equivalence of candidate devices. It is recommended
that the trace length not exceed 0.25 inch (6 mm).
Refer to Section 30.0 “Electrical Characteristics” for
additional information.
On “LF” devices, the internal core voltage regulator is
disabled. On these devices, the V
CAP/VDDCORE pin
must be externally connected to a suitable V
DDCORE
level voltage source at the circuit board level. Refer to
Section 30.0 “Electrical Characteristics” for the
allowed VDDCORE voltage range. Good power supply
bypassing practices should be used for the supply
source providing the V
CAP/VDDCORE voltage.
It is recommended to use a 0.1 µF ceramic capacitor
between V
CAP/VDDCORE and ground, placed as close
to the V
CAP/VDDCORE and VSS pins as possible.
FIGURE 2-3: FREQUENCY vs. ESR
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