MC1391
Figure 3. Frequency versus Temperature
Figure 4. Frequency Drift versus Warm–Up Time
40
30
30
20
10
Reference Frequency
= 15.750 Hz
0
–10
–20
–30
20
10
0
S3 in Position 2
–40
–50
–60
–70
Reference Frequency
= 15.750Hz
0
10
20
30
40
50
60
C)
70
80
0
30
60
90
120
T , AMBIENT TEMPERATURE (
°
t, TIME (s)
A
Figure 5. Mark Space Ratio
4.75
4.5
f
= 15,750 Hz
O
4.25
4.0
t = 63.5 µs
3.75
3.5
3.25
3.0
2.75
0
10
20
30
40
50
POSITIVE PULSE WIDTH (
µs)
Figure 6. Representative Schematic Diagram
Oscillator
Timing
V
6
CC
7
Pre–Driver
Oscillator
Regulator
Phase Detector
R22
R17
R14
330
R23
2k
2.15
10k
k
R8
R6
3.3k
5
R11
3.0k
2.4k
Z2
Q18
R1
2.6k
Phase
Detector
Output
Q14
Q13
D1
Q6
Q11
R
Mark–Space
D2
Z1
18
Q16
Ratio
Q4
Q7 Q8
R9
1.2k
8
Q15
7.5k
7.5k
R
4
R4 430
Q5
Q3
R12
820
Output
1
16
6.8k
R19
R20
Sawtooth
Input
R15
3.3k
Q10
Q1
R10
3.6k
Q12
Q17
Q2
510
Q9
R3 7.5k
R5 2.4k
D3
R21
910
R2 6.8k
470
R7
R13
240
D4
2
3
Ground
Sync Input
3
MOTOROLA ANALOG IC DEVICE DATA
MOTOROLA [ MOTOROLA ]
