MB39A214APFT-G-JNERE1 Datasheet, PDF (35/56 Pages) Fujitsu Component Limited. – 2ch DC/DC converter IC with PFM/ PWM synchronous rectification

MB39A214A
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
6 8 10 12 14 16 18 20 22 24 26 28
VIN [V]
Moreover, select the total quantity of the high-side FET electric charge as a guide that does not exceed the
total quantity of the high-side FET electric charge upper limit value shown below.
35
30
25
20
15
10
5
0
5
From the top line
FREQ=GND:CH1
FREQ=GND:CH2
FREQ=OPEN:CH1
FREQ=OPEN:CH2
FREQ=VB:CH1
FREQ=VB:CH2
10 15 20 25 30
Power supply voltage VIN [V]
Whether the mean current value that flows to switching FET is a rated value or less of switching FET is
judged. Each rating value for the switching FET can be calculated roughly by the following formula.
I_{D_Main} > I_{OUT_MAX} ¯ D
I_{D_Sync} > I_{OUT_MAX} ¯ (1 – D)
I_{D_Main} : high-side FET drain current [A]
I_{D_Sync} : Low-side FET drain current [A]
I_{OUT_MAX} : Maximum load current [A]
D
: On-duty
V_DSS > V_IN
V_DSS
: Voltage between the high-side FET drain and source and the low-side FET drain and
source [V]
V_IN : Power supply voltage [V]
DS405-00007-1v0-E
35