pic24hj16gp304 Microchip Technology Inc., pic24hj16gp304 Datasheet - Page 178

• Manufacturer Part Number: pic24hj16gp304
• Description: High-performance, 16-bit Microcontrollers
• Manufacturer: Microchip Technology Inc.

PIC24HJ32GP202/204 and PIC24HJ16GP304
18.2
All
PIC24HJ16GP304 devices power their core digital
logic at a nominal 2.5V. This can create a conflict for
designs that are required to operate at a higher typical
voltage, such as 3.3V. To simplify system design, all
devices
PIC24HJ16GP304 family incorporate an on-chip regu-
lator that allows the device to run its core logic from
V
The regulator provides power to the core from the other
V
(less than 5 ohms) capacitor (such as tantalum or
ceramic) must be connected to the V
(Figure 18-1). This helps to maintain the stability of the
regulator. The recommended value for the filter capac-
itor is provided in Section TABLE 21-13: “Internal
Voltage
Section 21.1 “DC Characteristics”.
On a POR
voltage regulator to generate an output voltage. During
this time, designated as T
disabled. T
resumes operation after any power-down.
FIGURE 18-1:
18.3
The Brown-out Reset (BOR) module is based on an
internal voltage reference circuit that monitors the reg-
ulated voltage V
module is to generate a device Reset when a brown-
out condition occurs. Brown-out conditions are gener-
ally caused by glitches on the AC mains (for example,
missing portions of the AC cycle waveform due to bad
power transmission lines, or voltage sags due to exces-
sive current draw when a large inductive load is turned
on).
DS70289A-page 176
DD
DD
Note 1:
.
pins. When the regulator is enabled, a low-ESR
of
On-Chip Voltage Regulator
BOR: Brown-Out Reset
,
Regulator
STARTUP
in
it takes approximately 20 μs for the on-chip
C
F
These are typical operating voltages. Refer
to Section TABLE 21-13: “Internal Volt-
age Regulator Specifications” located in
Section 21.1 “DC Characteristics” for the
full operating ranges of V
the
3.3V
DDCORE
the
is applied every time the device
PIC24HJ32GP202/204
CONNECTIONS FOR THE
ON-CHIP VOLTAGE
REGULATOR
V
V
V
Specifications”
PIC24HJ32GP202/204
. The main purpose of the BOR
DD
DDCORE
SS
PIC24H
STARTUP
/V
CAP
, code execution is
DD
DDCORE
and V
(1)
located
DDCORE
/V
CAP
.
and
and
Preliminary
pin
in
A BOR generates a Reset pulse, which resets the
device. The BOR selects the clock source, based on
the device Configuration bit values (FNOSC<2:0> and
POSCMD<1:0>).
If an oscillator mode is selected, the BOR activates the
Oscillator Start-up Timer (OST). The system clock is
held until OST expires. If the PLL is used, the clock is
held until the LOCK bit (OSCCON<5>) is ‘1’.
Concurrently, the PWRT time-out (TPWRT) will be
applied before the internal Reset is released. If TPWRT
= 0 and a crystal oscillator is being used, a nominal
delay of TFSCM = 100 is applied. The total delay in this
case is TFSCM.
The BOR Status bit (RCON<1>) is set to indicate that
a BOR has occurred. If the BOR circuit is enabled, it
continues to operate while in Sleep or Idle mode and
resets the device in case VDD falls below the BOR
threshold voltage.
© 2007 Microchip Technology Inc.