MPQ4559 – 1.5A, 2MHz, 55V STEP-DOWN CONVERTER AEC-Q100 QUALIFIED
Three events can shut down the chip: EN low,
VIN low and thermal shutdown. In the shutdown
procedure, power MOSFET is turned off first to
avoid any fault triggering. The COMP voltage and
the internal supply rail are then pulled down.
Programmable Oscillator
The MPQ4559 oscillating frequency is set by an
external resistor, RFREQ from the FREQ pin to
ground. The value of RFREQ can be calculated
from:
100000
RFREQ(kΩ) =
-5
fS(kHz)
To get fSW=500kHz, RFREQ=195kΩ.
MPQ4559 Rev. 1.01
5/24/2016
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