AM4962 Datasheet, PDF (12/16 Pages) BCD Semiconductor Manufacturing Limited – SINGLE PHASE FULL WAVE DIRECT PWM MOTOR DRIVER

Data Sheet
SINGLE PHASE FULL WAVE DIRECT PWM MOTOR DRIVER
AM4962
Typical Application (Note 4, Continued)
Note 4 (Refer to application circuit 2 unless otherwise noted.):
Adjust slope K of output PWM's duty vs. input PWM's duty
1. The default K is about 0.8 (application circuit 1).
2. Adding R5 can increase K (see Figure 12).
3. Adding R6 can decrease K (see Figure 13).
100
100
R5=270k, R1, R2, R3, R4, R6 Open
R5=560k, R1, R2, R3, R4, R6 Open
80
R1, R2, R3, R4, R5, R6 Open
80
60
60
40
40
20
0
0
10 20
30 40 50 60 70 80
Input PWM Duty Cycle (%)
90 100
20
0
0
R6=100k, R1, R2, R3, R4, R5 Open
R6=270k, R1, R2, R3, R4, R5 Open
R1, R2, R3, R4, R5, R6 Open
10 20 30 40 50 60 70 80 90 100
Input PWM Duty Cycle (%)
Figure 12
Figure 13
Adjust minimum duty of output PWM:
1. The default minimum duty of output PWM is about 20% (application circuit 1, Figure 10).
2. Decreasing R2 can increase minimum output PWM duty (see Figure 14).
3. Adding R5 can decrease minimum output PWM duty (see Figure 15).
80
70
R1=15k,R3,R4,R5,R6 open
60
50
40
30
20
10
3.5k
4.0k
4.5k
5.0k
5.5k
6.0k
6.5k
R2 (Ω)
Figure 14
100
R1, R2, R3, R4, R6 open
80
60
40
20
0
390K 560K 820K
1M
2.2M 4.7M 8.2M
R5 (Ω)
Figure 15
Apr. 2011 Rev. 1. 2
BCD Semiconductor Manufacturing Limited
12