M54640P
Application Description
•
PHASE INPUT
Phase input decides the output mode.
Phase
H
L
MA
H
L
MB
L
H
•
I0, I1
I0 and I1 fixed based on the comparison voltage V
R
decide the output current level.
The current level can be continuously changed by changing the voltage at V
R
continuously.
I0
H
L
H
L
I1
H
H
L
L
Current level
0
Low
Average
High
•
Current sensor
When the voltage fall at the current sensing resistor and the selected current level becomes of the same level, the
comparator triggers the monostable. Then, the output stage is cut off for a certain time (t
OFF
). During this cutoff time,
the current volume decreases slightly and falls short of the comparison level.
After the cutoff time (t
OFF
), the output stage is in ON state again.
This operation is repeated.
•
Single pulse generator
At the comparator output rise edge, the monostable is triggered.
The pulse width of the monostable at the external timing Rt and Ct is as follows.
t
OFF
= 0.69 x RtCt
Retrigger during t
OFF
is neglected.
•
Analog control
The output current level can be continuously changed by changing the voltage at V
R
or the feedback voltage to the
comparator.
Rev.1.0, Sep.19.2003, page 5 of 9
RENESAS [ RENESAS TECHNOLOGY CORP ]
