MB3888 Fuji Electric, MB3888 Datasheet - Page 16

• Manufacturer Part Number: MB3888
• Description: DC/DC Converter IC for Charging Li-ion Battery
• Manufacturer: Fuji Electric

16
MB3888
SETTING THE CHARGING VOLTAGE
The charging voltage (DC/DC output voltage) can be set by connecting external voltage setting resistors (R3,
R4) to the INE2 terminal (pin 7) according to the voltage at the INE2 terminal (pin 8) . Be sure to select a
resistor value that allows you to ignore the on resistor (35 , 1 mA) of the internal FET connected to the OUTD
terminal (pin 9) .In standby mode, the charging voltage is applied to OUTD termial. Therefore, output voltage
must be adjusted so that voltage applied to OUTD terminal is 17 V or less.
Battery charging voltage : V
METHOD OF SETTING THE CHARGING CURRENT
The charge current (output limit current) value can be set with the voltage at the INE1 terminal (pin 13) .
If a current exceeding the set value attempts to flow, the charge voltage drops according to the set current value.
Battery charge current setting voltage : INE1
METHOD OF SETTING THE TRIANGULAR WAVE OSCILLATION FREQUENCY
The triangular wave oscillation frequency can be set by the timing resistor (R
Triangular wave oscillation frequency : f
V
f
OSC
INE1 (V)
O
(V)
(kHz) : = 12690 R
(R3
20
R4)
I1 (A)
R4
T
(k )
R3
R4
O
R
S
INE2 (V)
( )
OUTD
INE2
INE2
V
O
CS
OSC
20
7
9
8
<Error Amp2>
T
) connected the RT terminal (pin 2) .