pic32mx320f064h Microchip Technology Inc., pic32mx320f064h Datasheet - Page 477

• Manufacturer Part Number: pic32mx320f064h
• Description: 64/100-pin General Purpose, 32-bit Flash Microcontrollers
• Manufacturer: Microchip Technology Inc.

25.4
All PIC32MX Family device’s core and digital logic are
designed to operate at a nominal 1.8V. To simplify sys-
tem designs, most devices in the PIC32MX Family
incorporate an on-chip regulator providing the required
core logic voltage from V
The internal 1.8V regulator is controlled by the
ENVREG pin. Tying this pin to V
lator, which in turn provides power to the core. A low
ESR capacitor (such as tantalum) must be connected
to the V
maintain the stability of the regulator. The recom-
mended value for the filer capacitor is provided in
Section 29.1 “DC Characteristics”.
Tying the ENVREG pin to V
this case, separate power for the core logic at a nomi-
nal 1.8V must be supplied to the device on the
V
Alternatively, the V
tied together to operate at a lower nominal voltage.
Refer to Figure 25-1 for possible configurations.
25.4.1
When the voltage regulator is enabled, it takes approxi-
mately 10 μs for it to generate output. During this time,
designated as T
T
operation after any power-down, including Sleep mode.
If the regulator is disabled, a separate Power-up Timer
(PWRT) is automatically enabled. The PWRT adds a
fixed delay of 64 ms nominal delay at device start-up.
25.4.2
When the on-chip regulator is enabled, PIC32MX Fam-
ily 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 specific in Section 29.1 “DC Characteris-
tics”.
25.4.3
The on-chip regulator is designed to meet the power-up
requirements for the device. If the application does not
use the regulator, then strict power-up conditions must
be adhered to. While powering up, V
never exceed V
© 2007 Microchip Technology Inc.
STARTUP
DDCORE
DDCORE
On-Chip Voltage Regulator
/V
is applied every time the device resumes
CAP
ON-CHIP REGULATOR AND POR
ON-CHIP REGULATOR AND BOR
POWER-UP REQUIREMENTS
DD
pin.
/V
STARTUP
CAP
DDCORE
by 0.3 volts.
pin (Figure 25-1). This helps to
, code execution is disabled.
DD
/V
SS
.
CAP
disables the regulator. In
DD
and V
enables the regu-
DD
DDCORE
pins can be
Advance Information
must
FIGURE 25-1:
Note 1:
Regulator Enabled (ENVREG tied to V
Regulator Disabled (ENVREG tied to ground):
(10 μF typ)
PIC32MX FAMILY
C
1.8V
EFC
These are typical operating voltages. Refer
to Section 29.1 “DC Characteristics” for
the full operating ranges of V
V
(1)
DDCORE
3.3V
3.3V
.
CONNECTIONS FOR THE
ON-CHIP REGULATOR
(1)
V
ENVREG
V
V
DD
DDCORE
SS
PIC32MX
V
ENVREG
V
V
DD
DDCORE
SS
PIC32MX
/V
CAP
DS61143A-page 475
/V
CAP
DD
and
DD
):