BD9853AFV

Technical Note

4/16

www.rohm.com

2009.05 - Rev.A

© 2009 ROHM Co., Ltd. All rights reserved.

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0

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180

0.01

0.1

1

10

100

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10000

100000

FREQUENCY[KHz]

0

10

20

30

40

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60

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80

90

100

1.31.41.51.61.71.8

1.92.02.12.22.32.42.52.6

FB VOLTAGE:VFB[V]

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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4

FB VOLTAGE[V]

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0

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4 4.2 4.4

FB VOLTAGE[V]

0

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0.00.2 0.40.6 0.81.0 1.21.4 1.61.8 2.02.2 2.42.6 2.83.0 3.23.4 3.63.8 4.0

(OUTL-GND) VOLTAGE[V]

VCC=4.5V

VCC=12V,18V

0

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0.00.2 0.40.60.81.0 1.21.41.6 1.82.02.2 2.42.62.8 3.0 3.23.43.6 3.8 4.0

(VCC-OUTH) VOLTAGE:[V]

VCC=12V,18V

VCC=4.5V

0

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0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0

(REGB-OUTH) VOLTAGE[V]

4

VCC=4.5V

VCC=12V,18V

0

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0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0

(REGA-OUTL) VOLTAGE[V]

VCC=12V,18V

VCC=4.5V

●

Characteristic Data

OUTL

OUTH

Fig.3 FB SINK CURRENT

Fig.5 OUTH SINK CURRENT

Fig.7 OUTL SINK CURRENT

Fig.1 FB VOLTAGE VS ON DUTY

Fig.2 ERROR AMP OPEN LOOP

Phase

Gain

Fig.4 FB SOURCE CURRENT

Fig.6 OUTH SOURCE CURRENT

Fig.8 OUTL SOURCE CURRENT