Diodes AM4962 - Manual (Page 12)

Data Sheet
SINGLE PHASE FULL WAVE DIRECT PWM MOTOR DRIVER AM4962
Apr. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
12
390K 560K 820K 1M 2.2M 4.7M 8.2M
0
20
40
60
80
100
Mi
n
imu
m D
u
ty
C
y
c
le
(
%
)
R5 ( Ω )
R1, R2, R3, R4, R6 open
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
R6=100k, R1, R2, R3, R4, R5 Open
R6=270k, R1, R2, R3, R4, R5 Open
R1, R2, R3, R4, R5, R6 Open
O
u
tput Duty
Cycle (%)
Input PWM Duty Cycle (%)
0 10 20 30 40 50 60 70 80 90 100
0
20
40
60
80
100
R5=270k, R1, R2, R3, R4, R6 Open
R5=560k, R1, R2, R3, R4, R6 Open
R1, R2, R3, R4, R5, R6 Open
O
u
tp
u
t D
u
ty
C
y
c
le
(
%
)
Input PWM Duty Cycle (%)
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).
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).
Figure 14 Figure 15
10
20
30
40
50
60
70
80
6.5k 6.0k 5.5k 5.0k 4.5k 4.0k
Mi
n
im
u
m D
u
ty
Cy
c
le
(
%
)
R2 ( Ω )
R1=15k,R3,R4,R5,R6 open
3.5k