User Manual

MP2307 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER
MP2307 Rev. 1.9 www.MonolithicPower.com 5
5/28/2008 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
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PIN FUNCTIONS
Pin # Name Description
1 BS
High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET
switch. Connect a 0.01µF or greater capacitor from SW to BS to power the high side switch.
2 IN
Power Input. IN supplies the power to the IC, as well as the step-down converter switches.
Drive IN with a 4.75V to 23V power source. Bypass IN to GND with a suitably large capacitor
to eliminate noise on the input to the IC. See Input Capacitor.
3 SW
Power Switching Output. SW is the switching node that supplies power to the output. Connect
the output LC filter from SW to the output load. Note that a capacitor is required from SW to
BS to power the high-side switch.
4 GND Ground (Connect the exposed pad to Pin 4).
5 FB
Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive
voltage divider connected to it from the output voltage. The feedback threshold is 0.925V. See
Setting the Output Voltage.
6 COMP
Compensation Node. COMP is used to compensate the regulation control loop. Connect a
series RC network from COMP to GND. In some cases, an additional capacitor from COMP to
GND is required. See Compensation Components.
7 EN
Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on
the regulator; low to turn it off. Attach to IN with a 100k pull up resistor for automatic startup.
8 SS
Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND
to set the soft-start period. A 0.1µF capacitor sets the soft-start period to 15ms. To disable the
soft-start feature, leave SS unconnected.