MB39A119 Datasheet, PDF (21/53 Pages) Fujitsu Component Limited. – DC/DC Converter IC of Synchronous Rectification for charging Li-ion battery

MB39A119
■ SETTING THE INPUT CURRENT
The input limit current value can be set at the analog voltage value of the +INE1 terminal (pin 7) .
Input current formula : IIN (A) =
+ INE1 (V)
25 × RS2 (Ω)
Input current setting voltage : + INE1
+ INE1 (V) = 25 × IIN (A) × RS2 (Ω)
■ SETTING THE OVERCURRENT DETECTION VALUE
The overcurrent is detected when the voltage difference is more than 0.2 V (Typ) between +INE2 terminal (pin
10) voltage and -INE2 terminal (pin 11) voltage.
0.2 (V)
Charge overcurrent detection value : Iocdet (A) =
RS1 (Ω)
Charge current and overcurrent detection value by RS1 value (example)
RS1
+INE2
Ichg
33 mΩ
0.5 V to 3.5 V
0.6 A to 4.2 A
15 mΩ
0.5 V to 3.5 V
1.3 A to 9.3 A
OCDet
6A
13 A
■ SETTING THE TRIANGULAR WAVE OSCILLATION FREQUENCY
The triangular wave oscillation frequency can be set by the timing resistor (RT) connected to the RT terminal
(pin 18) .
Triangular wave oscillation frequency : fOSC
fosc (kHz) =:
19500
RT (kΩ)
21