4

■Typical characteristics

• Vout=2.7V (ELM9527D)

(Top=25°C, L=220μH, D=MA721, C=47μF)

012

1

2

3

Vin (V)

Vout - Vin

Iout =1mA

3mA

10mA

012

50

60

70

80

90

100

0

10

20

30

40

50

Vin (V)

VRp-p

EFFICIENCY

EFFICIENCY-Vin

RIPPLE VOLTAGE-Vin

EFFICIENCY

RIPPLE VOLTAGE

■External parts

When choosing choke coil, please select that whose core is not magnetically saturated, DC resistance is

low, and which has sufficient margin for rated current.

For ELM95 series, ELM recommends following coil.

• CM-5/CM-5N (Sumida Electric Co., Ltd.)

1) Coil

When choosing diode, please select that whose forward voltage is small, switching speed is high and which

has sufficient margin for rated current. For ELM95 series, ELM recommends schottoky diodes.

2) Diode

When choosing capacitor, please select that whose capacity is comparatively large and voltage limit is at

least three times larger than rated output voltage of used ELM95 series. For ELM95 series, ELM recom-

mends to use “Aluminum electrolytic capacitor”. When using capacitors such as “Tantalum capacitor” or

“Laminated ceramic capacitor”, there may be cases that few hundred hertz wave motion will happen in out-

put voltage wave form. Under such circumstances, ELM recommends connecting resistance (1.0Ω approx.)

to capacitor serially as following.

3) Capacitor

To design DC/DC converter with ELM95 series, coil, diode, and capacitor are necessary.

(Refer to standard circuit configuration.)

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