AN-087E Rev.1.0

April-2011

8

FA5526/5527/5528/5536/5537/5538

Fuji Electric Co., Ltd.

http://www.fujielectric.co.jp/products/semiconductor/

Current sensor (IS pin)

Item

Symbol

Condition

MIN

TYP

MAX

Unit

Voltage gain

⊿VFB/⊿VIS

3.8

4.0

4.2

V/V

Maximum threshold voltage

FB pin = 4V, duty = 10%

470

520

570

mV

FA5526/36

-24

FA5527/37

-17

Slope compensation value

SLP

FB pin=4V

FA5528/38

-12

mV/us

FA5526/36

0.3

FA5527/37

0.5

Minimum ON pulse width

Tmin

FB pin=3V

CS pin=0V

IS pin=1V

FA5528/38

0.7

us

FA5526/36

0.2

FA5527/37

0.4

Blanking time

Tblank

FA5528/38

0.6

us

Output delay time

IS pin to OUT pin

100

ns

Soft-start circuit (CS pin)

Item

Symbol

Condition

MIN

TYP

MAX

Unit

Charging current

CS pin = 0V

-15

-11

-5

uA

Threshold voltage for

changing charging current

Ics = -12

 -4

µA

3

V

Input threshold voltage

OUT pin width = Tmin,

FB pin = 3V

0.68

V

Over Current Protection circuit (CS pin) : Latch OFF for FA5526/27/28 and Auto-Recovery for FA5536/37/38

Item

Symbol

Condition

MIN

TYP

MAX

Unit

Charging current

CS pin = 4V

-6

-4

-2

uA

Sink current

CS pin = 6V

34

59

84

uA

ON

→OFF

8.0

8.5

9.0

V

Cutoff threshold voltage

OFF

→ON

7.4

7.9

8.4

V

Hysteresis width

0.6

V

Clamp voltage at latch mode

FB pin : open

8.9

V

Cutoff circuit at overload (FB pin)

Item

Symbol

Condition

MIN

TYP

MAX

Unit

Detection threshold voltage

3.3

3.6

3.9

V

Cutoff circuit at overvoltage (VCC pin)

Item

Symbol

Condition

MIN

TYP

MAX

Unit

Threshold voltage

26

28

30

V

CS pin charging current

CS pin = 4V

-1.3

mA