Datasheet

 2011 Microchip Technology Inc. DS39932D-page 33
PIC18F46J11 FAMILY
2.4 Voltage Regulator Pins (VCAP/
V
DDCORE)
When the regulator is enabled (“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/
V
DDCORE pin must not be connected to VDD 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 Ta ble 2 - 1 . Capacitors with
equivalent specifications can be used.
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 28.0 “Electrical
Characteristics” for additional information.
When the regulator is disabled (“LF” devices), the
V
CAP/VDDCORE pin must be tied to a voltage supply at
the V
DDCORE level. Refer to Section 28.0 “Electrical
Characteristics” for information on V
DD and
V
DDCORE.
Note that the “LF” versions are provided with the
voltage regulator permanently disabled; they must
always be provided with a supply voltage on the
VDDCORE pin.
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