Technical Note

5/17

www.rohm.com

2010.06 - Rev.A

© 2010 ROHM Co., Ltd. All rights reserved.

BD8963EFJ

●

Information on advantages

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

Voltage drop due to sudden change in load was reduced by about 50%.

Fig.17 Comparison of transient response

Advantage 2 : Offers high efficiency with synchronous rectifier

Utilizes the synchronous rectifying mode and the low on-resistance MOS FETs incorporated as power transistor.

ON resistance of P-channel MOS FET : 145mΩ(Typ.)

ON resistance of N-channel MOS FET : 80mΩ(Typ.)

Advantage 3 :・Supplied in smaller package due to small-sized power MOS FET incorporated.

Reduces a mounting area required.

Fig.19 Example application

DC/DC

Convertor

Controller

L

Co

Cin

10mm

15mm

L

・

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

・

Inductance L required for the operating frequency of 1 MHz: 1.5μH inductor

75mV

36mV

Fig.18 Efficiency

0

10

20

30

40

50

60

70

80

90

100

10

100

1000

10000

VCC=5.0V

Ta=25℃

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