MP1471A – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
PIN FUNCTIONS
Package
Pin #
Name Description
System Ground. Reference ground of the regulated output voltage: requires extra care
during PCB layout. Connect to GND with copper traces and vias.
1
2
3
GND
SW
IN
Switch Output. Connect using wide a PCB trace.
Supply Voltage. The MP1471A operates from a 4.5V-to-16V input rail. Requires C1 to
decouple the input rail. Connect using a wide PCB trace.
Feedback. Connect to the tap of an external resistor divider from the output to GND to set
the output voltage. The frequency fold-back comparator lowers the oscillator frequency
when the FB voltage drops below 140mV to prevent current-limit runaway during a short
circuit fault.
4
FB
EN=HIGH to enable the MP1471A. For automatic start-up, connect EN to VIN using a
100kꢀ resistor.
5
6
EN
Bootstrap. Connect a capacitor and a resistor between SW and BST pins to form a floating
supply across the high-side switch driver. Use a 1µF BST capacitor.
BST
MP1471A Rev. 1.0
12/12/2013
www.MonolithicPower.com
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