MB39A132QN-G-ERE1 Fujitsu Semiconductor America Inc, MB39A132QN-G-ERE1 Datasheet - Page 35

• Manufacturer Part Number: MB39A132QN-G-ERE1
• Description: IC CONV DC-DC LI-ION 32QFN
• Manufacturer: Fujitsu Semiconductor America Inc

Specifications of MB39A132QN-G-ERE1

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Operating Temperature: 25°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1020

■ APPLICATION NOTE
DS04–27265–3E
• Inductor selection
As a rough guide, the inductance of an inductor should keep the peak-to-peak value of inductor ripple current
below 50% of the maximum charge current. The inductance fulfilling the above condition can be found by
the following formula.
The minimum charge current (critical current) in the condition that inductor current does not flow in reverse
can be found by the following formula.
The maximum value of the current flowing through the inductor needs to be found in order to determine
whether the current flowing through the inductor is within the rated value. The maximum current flowing
through the inductor can be found by the following formula.
ΔIL ≥
I
L ≥
IL
OC
L
I
LOR : Inductor ripple current peak to peak value - Maximum charge current ratio (0.5)
V
V
f
I
L
V
V
f
IL
I
ΔIL : Inductor ripple current peak to peak value [A]
OMAX
OSC
OC
OSC
OMAX
MAX
O
O
IN
IN
MAX
=
≥ Io
LOR × I
: Inductance [H]
: Maximum charge current [A]
: Switching power-supply voltage [V]
: Charge voltage [V]
: Switching frequency [Hz]
: Critical current [A]
: Inductance [H]
: Switching power-supply voltage [V]
: Charge voltage [V]
: Switching frequency [Hz]
: Maximum inductor current [A]
: Maximum charge current [A]
2 × L
V
V
V
IN
IN
MAX
O
L
− V
− V
+
OMAX
O
O
×
×
ΔIL
V
2
V
Inductor current
IL
Io
×
IN
V
IN
MAX
MAX
IN
× f
I
− V
OC
V
V
× f
0
OSC
O
IN
O
OSC
V
× f
O
OSC
The current is shifting according to the charge current.
ΔIL
Time
MB39A132
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