MP1584 – 3A, 1.5MHz, 28V STEP-DOWN CONVERTER
MP1584 Rev. 1.0
www.MonolithicPower.com
4
8/8/2011
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PIN FUNCTIONS
SOIC
Pin #
Name Description
1 SW
Switch Node. This is the output from the high-side switch. A low forward drop Schottky diode to
ground is required. The diode must be close to the SW pins to reduce switching spikes.
2 EN
Enable Input. Pulling this pin below the specified threshold shuts the chip down. Pulling it up
above the specified threshold or leaving it floating enables the chip.
3 COMP
Compensation. This node is the output of the error amplifier. Control loop frequency
compensation is applied to this pin.
4 FB
Feedback. This is the input to the error amplifier. The output voltage is set by a resistive divider
connected between the output and GND which scales down V
OUT
equal to the in0.8V
reference.
5
GND
Exposed
Pad
Ground. It should be connected as close as possible to the output capacitor to shorten the high
current switch paths. Connect exposed pad to GND plane for optimal thermal performance.
6 FREQ
Switching Frequency Program Input. Connect a resistor from this pin to ground to set the
switching frequency.
7 VIN
Input Supply. This supplies power to all the internal control circuitry, both BS regulators and the
high-side switch. A decoupling capacitor to ground must be placed close to this pin to minimize
switching spikes.
8 BST
Bootstrap. This is the positive power supply for the internal floating high-side MOSFET driver.
Connect a bypass capacitor between this pin and SW pin.