BD8964FVM

Technical Note

5/13

www.rohm.com

2009.05 - Rev.A

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

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Information on advantages

Advantage 1：Offers fast transient response with current mode control system.

Voltage drop due to sudden change in load was reduced

Fig.17 Comparison of transient response

Advantage 2： Offers high efficiency with synchronous rectifier

・

For heavier load:

Utilizes the synchronous rectifying mode and the low on-resistance

MOS FETs incorporated as power transistor.

ON resistance of P-channel MOS FET : 350mΩ(Typ.)

ON resistance of N-channel MOS FET : 250mΩ(Typ.)

Advantage 3：・ Supplied in smaller package due to small-sized power

MOS FET incorporated.

Reduces a mounting area required.

Fig.19 Example application

L

Co

Cin

10mm

15mm

L

Fig.18 Efficiency

・

Output capacitor Co required for current mode control: 10μF ceramic capacitor

・

Inductance L required for the operating frequency of 1 MHz: 4.7μH inductor

DC/DC

Convertor

Controller

110mV

58mV

0

10

20

30

40

50

60

70

80

90

100

1

10

100

1000

10000

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VCC=5V

Ta=25℃