NCP5314 ON Semiconductor, NCP5314 Datasheet - Page 26

• Manufacturer Part Number: NCP5314
• Description: Two/Three/Four-Phase Buck CPU Controller
• Manufacturer: ON Semiconductor

10. Current Limit Setting
block diagram) exceeds the voltage on the I
will latch off. For inductive sensing, the I
should be set based on the inductor’s maximum resistance
(R
resistance increase due to current heating and ambient
temperature rise. Also, depending on the current sense
points, the circuit board may add additional resistance. In
general, the temperature coefficient of copper is +0.39% per
_C. To set the level of the I
When the output of the current sense amplifier (COx in the
LMAX
V ILIM + (I OUT,LIM ) DI Lo 2) @ R @ G ILIM
). The design must consider the inductor’s
LIM
pin:
LIM
LIM
pin, the part
pin voltage
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NCP5314
26
where:
current sense time constant (RC) should be slightly larger
than the R
a step load change will cause the sensed current waveform
to appear larger than the actual inductor current and will trip
the current limit at a lower level than expected.
I
R is R
G
For the overcurrent protection to work properly, the
OUT,LIM
I
ILIM
Lo
/2 is half the inductor ripple current;
LMAX
is the current sense to I
L
time constant. If the RC time constant is too fast,
is the current limit threshold of the converter;
+ R
PCB;
LIM
gain.