PIC18F2450 Datasheet, PDF (288/320 Pages) Microchip Technology – 28/40/44-Pin, High-Performance, 12 MIPS, Enhanced Flash, USB Microcontrollers with nanoWatt Technology

PIC18F2450/4450
FIGURE 21-8:
BROWN-OUT RESET TIMING
VDD
VIRVST
Enable Internal
Reference Voltage
Internal Reference
Voltage Stable
BVDD
35
36
VBGAP = 1.2V
TABLE 21-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No.
Symbol
Characteristic
Min Typ Max Units
Conditions
30
TmcL MCLR Pulse Width (low)
31
TWDT Watchdog Timer Time-out Period
(no postscaler)
32
TOST Oscillator Start-up Timer Period
33
TPWRT Power-up Timer Period
34
TIOZ I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
35
TBOR Brown-out Reset Pulse Width
36
TIRVST Time for Internal Reference
Voltage to become Stable
37
TLVD Low-Voltage Detect Pulse Width
38
TCSD CPU Start-up Time
39
TIOBST Time for INTRC to Stabilize
Legend: TBD = To Be Determined
2
—
—
—
4.00 TBD
1024 TOSC — 1024 TOSC
—
65.5 TBD
—
2
—
200
—
—
—
20
50
200
—
—
5
—
10
—
1
—
μs
ms
— TOSC = OSC1 period
ms
μs
μs VDD ≤ BVDD (see D005)
μs
μs VDD ≤ VLVD
μs
ms
DS39760A-page 286
Advance Information
© 2006 Microchip Technology Inc.