MB3881 Datasheet, PDF (25/40 Pages) Fujitsu Component Limited. – 8-ch DC/DC Converter IC with Synchronous Rectifier for Voltage Step-up and Step-down

MB3881
s SETTING THE OUTPUT CURRENT
The output circuit (drive 8) is structured as illustrated below (in the output circuit diagram). As found in “Output
Current Waveform” below, the source current value of the output current waveform has a constant current setting.
Note that the source current is set by the following equation:
Output source current : (VB / RB) × 80 =: 48 / RB[A] (VB =: 0.6 V)
59 _{VCC (O)−2}
Source current
I
80 I
External NPN transistor
× 33
Output source
current
64 _OUT8
Output sink
current
Sink current
× 33
70 kΩ
0.6 V
In the output circuit diagram
RB8
2
RB VB =: 0.6 V
1 GND (O)−2
Output source current (Peak)
Output source
current
0
Output sink current (Peak)
t
Output current waveform
25