MB39A119 Fujitsu, MB39A119 Datasheet - Page 20

• Manufacturer Part Number: MB39A119
• Description: DC/DC Converter IC
• Manufacturer: Fujitsu

20
MB39A119
SETTING THE CHARGE VOLTAGE
The charge voltage (DC/DC output voltage) can be set by connecting external output voltage setting resistors
(R1 and R2) to the -INE3 terminal (pin 15) . Be sure to select a resistor value that allows you to ignore the on-
resistance (35 Ω at 1 mA) of internal FET connected to the OUTD terminal (pin 16).
SETTING THE CHARGE CURRENT
The charge current value can be set at the analog voltage value of the +INE2 terminal (pin 12) .
SETTING THE INPUT CURRENT
The input limit current value can be set at the analog voltage value of the +INE1 terminal (pin 7) .
Charge current formula : Ichg (A) =
Battery charge current setting voltage : + INE2
Input current formula : I
Input current setting voltage : + INE1
+ INE2 (V) = 24.5 × Ichg (A) × R
+ INE1 (V) = 25 × I
Battery charge voltage : V
V
O
(V) =
R1 + R2
IN
R2
(A) × R
IN
R1
R2
(A) =
B
× − INE3 (V)
S2
V
O
O
(Ω)
−INE3
OUTD
S1
(Ω)
24.5 × R
15
16
+ INE2 (V)
S1
(Ω)
25 × R
+ INE1 (V)
S2
(Ω)
<Error Amp3>
4.2 V
−
+