BD8622EFV_09 Datasheet, PDF (9/16 Pages) Rohm – Built-in 1ch FET Light Load Type DC / DC converters

BD8622EFV
Technical Note
Light load mode operation
・Low current mode
When the terminal MODE (17 pins) is made "H", low current mode operation becomes effective. The characteristic of the
efficiency valuing is obtained in low current mode operation at a light load.
V_OUT
[20mV/DIV]
SW
[2V/DIV]
I_L
[200mA/DIV]
Fig.5 Low current mode operation
・Low ripple mode
When the terminal MODE is made "L", the Low ripple mode operation becomes effective. It becomes operation of valuing a
low ripple in the Low ripple mode operation at a light load.
VOUT
[20mV/DIV]
SW
[2V/DIV]
IL
[200mA/DIV]
Fig.6 Low ripplemord operation
100
90 _{Low current mode}
80
70
60
50
40
Low ripple mord
VIN=3.3V
VO=1.8V
30
Io=0～100mA
SW_f=550KHz(R11=220KΩ)
20
10
0
1
10
100
Negative overcurrent [mA]
Fig7 Light load mode efficiency comparison
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9/15
2009.05 - Rev.A