Datasheet

Datasheet

18/34

TSZ02201-0F1F0C100240-1-2

© 2013 ROHM Co., Ltd. All rights reserved.

15.Feb.2016 Rev.006

www.rohm.com

TSZ22111・15・001

BD9486F

●3.2.7 OVP Setting

The OVP terminal is the input for over-voltage protection of output voltage.

The OVP pin is high impedance, because the internal resistance is not connected to a certain bias.

Detection voltage of VOUT is set by dividing resistors R1 and R2. The resistor values can be calculated by the formula

below.

○OVP detection equation

voltage of OVP, R1, R2 can be expressed by the following formula.

○OVP release equation

By using R1 and R2 in the above equation, the release voltage of

【setting example】

If the normal output voltage, VOUT is 40V, the detect voltage of OVP is 48V, R2 is 10k ohm, R1 is calculated as follows.

●3.2.8 Interval Until Latch Off Setting

About over boost protection (FBMAX), the capacitance value of CP terminal can set the time of latch-off. About the

behavior from abnormal detection to latch-off, please refer to the section “3.5.6 Timing Chart”.

The condition FB>4.0V(typ.) and PWM=H continues more than four GATE clocks, the CP terminal charge is started by

3μA. After that, only the FB voltage is monitored. As the CP voltage reaches to 3.0V(typ.), IC will be latched off.

【setting example】

If the capacitor of CP pin is 0.47μF, the timer latch interval is as follows.

Figure 27. OVP setting example

]

k

[

]

V

[

.

])

V

[

.

]

V

[

VOVP

(

]

k

[

R

R

DET











0

3

0

3

2

1

]

V

[

]

k

[

R

])

k

[

R

]

k

[

R

(

V

.

VOVP

CAN













2

2

1

8

2

]

k

[

]

V

[

])

V

[

]

V

[

(

]

k

[

]

V

[

.

])

V

[

.

]

V

[

VOVP

(

]

k

[

R

R

DET





















　

150

3

3

48

10

0

3

0

3

2

1

]

V

[

.

]

V

[

]

k

[

]

k

[

]

k

[

]

V

[

.

]

k

[

R

])

k

[

R

]

k

[

R

(

]

V

[

.

VOVP

CAN

　

　

8

44

10

150

10

8

2

2

2

1

8

2



























　

　

　

　

[sec]

]

A

[

.

]

V

[

.

]

F

[

C

LATCH

CP

TIME









0

3

0

3

　

　

　

　

　

　

sec]

m

[

]

A

[

.

]

V

[

.

]

F

[

.

LATCH

TIME

470

0

3

0

3

47

0









