MB39A114 Datasheet, PDF (19/54 Pages) Fuji Electric – DC/DC Converter IC for Charging Li-ion Battery

MB39A114
s SETTING THE CHARGING VOLTAGE
The setting of the charging voltage is switched to 3 cell or 4 cell by the SEL terminal. As for the charge voltage,
the SEL terminal becomes 16.8 V at “H” level. It become 12.6 V at “L” level.
Charging voltage of battery : VO
VO (V) = (150 kΩ + 50 kΩ) /50 kΩ × 4.20 V = 16.8 (SEL = H)
VO (V) = (150 kΩ + 50 kΩ) /50 kΩ × 3.15 V = 12.6 (SEL = L)
−INC2
VO B
1
R3
−INE3
16
150 kΩ
R4 50 kΩ
<Error Amp3>
−
+
+
CS
22
SEL
11
3.15 V
4.2 V
s SETTING THE CHARGING CURRENT
The charging current value (output limit current value) is set at the +INE2 terminal (pin 3) .
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 : +INE2
+INE2 (V) = 20 × I1 (A) × RS (Ω)
s SETTING THE TRIANGULAR WAVE OSCILLATION FREQUENCY
The triangular wave oscillation frequency can be set by connecting a timing resistor (RT ) to the RT terminal (pin
17) .
Triangular wave oscillation frequency : fosc
fosc (kHz) =: 14100/RT (kΩ)
19