Datasheet

PIC16C7X
DS30390E-page 248  1997 Microchip Technology Inc.
Applicable Devices 72 73 73A 74 74A 76 77
FIGURE 21-22: TYPICAL XTAL STARTUP
TIME vs. VDD (LP MODE, 25°C)
FIGURE 21-23: TYPICAL XTAL STARTUP
TIME vs. V
DD (HS MODE, 25°C)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
V
DD(Volts)
Startup Time(Seconds)
32 kHz, 33 pF/33 pF
200 kHz, 15 pF/15 pF
7
6
5
4
3
2
1
4.0 4.5 5.0 5.5 6.0
V
DD(Volts)
Startup Time(ms)
20 MHz, 33 pF/33 pF
8 MHz, 33 pF/33 pF
8 MHz, 15 pF/15 pF
20 MHz, 15 pF/15 pF
FIGURE 21-24: TYPICAL XTAL STARTUP
TIME vs. VDD (XT MODE, 25°C)
TABLE 21-2: CAPACITOR SELECTION
FOR CRYSTAL
OSCILLATORS
Osc Type
Crystal
Freq
Cap. Range
C1
Cap. Range
C2
LP 32 kHz 33 pF 33 pF
200 kHz 15 pF 15 pF
XT 200 kHz 47-68 pF 47-68 pF
1 MHz 15 pF 15 pF
4 MHz 15 pF 15 pF
HS 4 MHz 15 pF 15 pF
8 MHz 15-33 pF 15-33 pF
20 MHz 15-33 pF 15-33 pF
Crystals
Used
32 kHz Epson C-001R32.768K-A ± 20 PPM
200 kHz STD XTL 200.000KHz ± 20 PPM
1 MHz ECS ECS-10-13-1 ± 50 PPM
4 MHz ECS ECS-40-20-1 ± 50 PPM
8 MHz EPSON CA-301 8.000M-C ± 30 PPM
20 MHz EPSON CA-301 20.000M-C ± 30 PPM
70
60
50
40
30
20
10
0
3.0 3.52.5 4.0 5.0 5.5 6.04.5
V
DD(Volts)
Startup Time(ms)
200 kHz, 68 pF/68 pF
200 kHz, 47 pF/47 pF
1 MHz, 15 pF/15 pF
4 MHz, 15 pF/15 pF
Data based on matrix samples. See first page of this section for details.