18

SLA7024M, SLA7026M, SLA7027MU, SLA7022MU, SLA7029M,

SMA7022MU, SMA7029M, SLA7020M, SLA7021M and SDK03M

Application Note

Fig. 6 Circuit for fixing the coil current

Fig. 7 Circuit for fixing the coil current

Fig. 8 and 9 show the graphs of equations q and w ,

respectively.

Fig. 8 Output current Io vs. Current detection resistor Rs

NOTE:

Ringing noise is produced in the current detection resistor

Rs when the MOSFET is switched ON and OFF through

chopping. This noise is also generated in feedback signals

from Rs which may therefore causes the comparator to

malfunction.

added in order to act as noise filter.

However, when the values of these constants are increased,

the response from Rs to the comparator becomes slow.

Hence, the value of the output current lo is higher to some

extent than the computed value.

SLA7024M

SLA7026M

SLA7027MU

9,(10)

3,(14)

Power down

signal

SDK03M

10

3

Power down

signal

13 15

4

3

2

1

0

01234

Ω)

SLA7024M, SLA7026M, SLA7029M, SLA7027MU,

SLA7022MU, SLA7020M, SLA7021M, SMA7029M,

SMA7022MU, SDK03M

Ω

Ω

∞

·

2

1.5

1

0.5

00

2.0

4.0

6.0

8.00

Ω)

SLA7024M, SLA7026M, SLA7029M, SLA7027MU, SLA7022MU,

SLA7020M, SLA7021M, SMA7029M, SMA7022MU, SDK03M

1000

1200

Ω

Ω

Ω

1+

Ω

Ω

1

·