PIC32MX5XX_11 Datasheet, PDF (174/256 Pages) Microchip Technology – High-Performance, USB, CAN and Ethernet 32-bit Flash Microcontrollers

PIC32MX5XX/6XX/7XX
28.3 On-Chip Voltage Regulator
All PIC32MX5XX/6XX/7XX devices’ core and digital
logic are designed to operate at a nominal 1.8V. To
simplify system designs, most devices in the
PIC32MX5XX/6XX/7XX family incorporate an on-chip
regulator providing the required core logic voltage from
VDD.
A low-ESR capacitor (such as tantalum) must be
connected to the VCAP/VCORE pin (see Figure 28-2).
This helps to maintain the stability of the regulator.
The recommended value for the filter capacitor is
provided in Section 31.1 “DC Characteristics”.
Note:
It is important that the low-ESR capacitor
is placed as close as possible to the
VCAP/VCORE pin.
28.3.1 ON-CHIP REGULATOR AND POR
It takes a fixed delay for the on-chip regulator to generate
an output. During this time, designated as TPU, code
execution is disabled. TPU is applied every time the
device resumes operation after any power-down,
including Sleep mode.
28.3.2 ON-CHIP REGULATOR AND BOR
PIC32MX5XX/6XX/7XX devices also have a simple
brown-out capability. If the voltage supplied to the
regulator is inadequate to maintain a regulated level,
the regulator Reset circuitry will generate a Brown-out
Reset. This event is captured by the BOR flag bit
(RCON<1>). The brown-out voltage levels are
specified in Section 31.1 “DC Characteristics”.
28.3.3 POWER-UP REQUIREMENTS
The on-chip regulator is designed to meet the power-up
requirements for the device. If the application does not
use the regulator, strict power-up conditions must be
adhered to. While powering up, VCORE must never
exceed VDD by 0.3V.
FIGURE 28-2:
CONNECTIONS FOR THE
ON-CHIP REGULATOR
3.3V⁽¹⁾
PIC32
VDD
CEFC⁽²⁾
(10 μF typ)
VCAP/VCORE
VSS
Note 1:
2:
These are typical operating voltages. Refer
to Section 31.1 “DC Characteristics” for
the full operating ranges of VDD and
VCORE.
It is important that the low-ESR capacitor
is placed as close as possible to the
VCAP/VCORE pin.
DS61156G-page 174
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