MB3885PFV FUJITSU [Fujitsu Component Limited.], MB3885PFV Datasheet - Page 21

• Manufacturer Part Number: MB3885PFV
• Description: 1-channel DC/DC Converter IC with Synchronous Rectifier
• Manufacturer: FUJITSU [Fujitsu Component Limited.]

PRECAUTIONS RELATED TO SUPPLY VOLTAGE RANGE
Although the supply voltage range listed under recommended operating requirements is 5.5V-18V, generation
of heat limits the maximum operating supply voltage since the IC’s internal loss varies with the frequency of
oscillation and FET’s total gate charge. When using the MB 3885 in an application, caution must be taken in
relation to supply voltage range.
As shown below, I
gate capacitance (C
Because IC current consumption other than I
following formula.
Power consumption : Pc
Pc (W) : = 0.0065
I
B
(A)
I
Ibias
1
I
2
1
B
V
(average current) can be determined from the total gate charge Qg
iss1
CC
T1
T
, C
V
iss2
CC
, C
Qg
T
rss1
I
1
B
, C
1 2
Ibias
rss2
) of the external FET Q1, Q2, by the following formula.
2
V
B
T2
T
B
I
B
is 6.5 mA, power consumption can be determined from the
Qg
T
2
(Ibias
1
Ibias
2
: = 2 mA)
1
, Qg
2
, charged from the
MB3885
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