MB39A123 Datasheet, PDF (33/44 Pages) Fujitsu Component Limited. – 6 ch DC/DC Converter IC with Synchronous Rectification

MB39A123
• Vo characteristics (Vop) when turning on CTL at CHCTL ON
CTL[V] ¹⁰
At evaluating Fujitsu EV board system
5
0
Vo[V] ₅
4
3
2
1
0
CTL
2
3
Generated voltage
Vop =: 0.4 V
1
CS
Vo
CS[V]
2
1
0
0 2 4 6 8 10 12 14 16 18 20 ^t[ms]
Step-down operation
VIN = 7.2 V
Vo = 5 V
L = 15 µH
Co = 2.2 µF
Load = 50 Ω
CHCTL = ON
VD
L
IL
D
Vo
Co
Generated output voltage - Output capacitor value
600
At evaluating Fujitsu EV board system
500
Ta = + 25 °C
VCC = CTL = 7.2 V
400
When no load is
applied
300
200
100
0
1
L = 6.8 µH
L = 68 µH
10
100
Output capacitor value Co (µF)
TON
VD _VIN
IL
Ip
Ip = VIN / L × TON
This energy Q
moves to Co
Vo
Vop
Vop = Q / Co
33