MV1012SC

10

Table 1 Recommended MOSFETs (as of January 2015)

Product name

Withstand

voltage (V)

Id (A) Ron (typ) Ron (max) Qg (nC) Ciss (pF) Coss (pF) Manufacturer Package

P3B28HP2

280

3

1.7

2

3.6

120

25

Shindengen

FB

P6B28HP2

6

0.66

0.85

5.7

240

43

Shindengen

FB

P1R5B40HP2

400

1.5

4.2

5

3.9

120

20

Shindengen

FB

P4B40HP2

4

1.54

1.9

6.5

245

33

Shindengen

FB

P1B52HP2

525

1

6

7.2

4.3

125

20

Shindengen

FB

P5B52HP2

5

1.4

1.7

10.5

400

45

Shindengen

FB

P6B52HP2

6

1.1

1.35

15

520

58

Shindengen

FB

P0R5B60HP2

600

0.5

8.3

10

4.3

120

18

Shindengen

FB

3.2.2

Fly-wheel diode (D1)

Just as with MOSFETs, the fly-wheel diode must have withstand voltage greater than the input voltage. Additionally,

select a fast recovery diode (FRD) suitable for high-speed switching with trr of around 100 nsec or less. (See Table 2

Recommended fly-wheel diodes.)

Table 2 Recommended fly-wheel diodes (as of January 2015)

Product name

Withstand

voltage (V)

Io (A)

Cj (pF)

trr (ns)

Manufacturer Package

D1FL20U

200

1.1

0.98

-

35

Shindengen

1F

D2FL20U

1.5

0.98

-

35

Shindengen

2F

D1FL40U

400

1.5

1.2

11

25

Shindengen

1F

D2FL40

1.3

1.3

-

50

Shindengen

2F

D1FK60

600

0.8

1.3

11

75

Shindengen

1F

D2FK60

1.5

1.3

16

75

Shindengen

2F

3.2.3

Current detection resistor (R1 and R2)

The current detection threshold of the CS pin should be Vth_CS = 0.495 V, and R1/R2 = Rcs. In Figure 5, when toff2 is

significantly less than ton or toff1, the peak current of Id, Ip, is double the output current Io. Thus, the Rcs is calculated

using the output current when the dimming ratio is 100%, Io (max), as follows:

In actual use, the current will vary slightly from the calculated value due to toff2 and detection delay. Adjust to the

appropriate resistance with the actual apparatus.

(max)

Io

2

495

.

0

Ip

th_CS

V

Rcs







CAT.No.1A0602-1E