AN1139 STMicroelectronics, AN1139 Datasheet - Page 59

• Manufacturer Part Number: AN1139
• Description: L6254 - L6268 - L6269 12V DISK DRIVE POWER COMBO IC
• Manufacturer: STMicroelectronics

Figure 39c. Mathcad Analisys of the Voice Coil Current Loop
CLOSE LOOP RESPONSE
A
arg(
20 log(
.
CL( ) n
Ksen Rs
CL( ) n
)
.
.
360
. 2
.
)
180
120
Ri
Rf
120
180
60
60
25
20
15
10
0
10
15
20
25
5
0
5
10
10
A
=
1
100
100
CL( ) n
MAGNITUDE RESPONSE in DB
PHASE RESPONSE in Degrees
1
1000
H( ) n
1000
. A H( ) n
f( ) n
f( ) n
1 10
1 10
4
20 log(
4
.
AN1139 APPLICATION NOTE
CL( ) 1
1 10
)
5
1 10
=
1.464 10
5
1 10
6
6
0
1 10
6
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