MP2187 – DUAL 3A, 5.5V, 1.2MHz, SYNCHRONOUS STEP-DOWN SWITCHER

MP2187 Rev. 1.0

www.MonolithicPower.com

13

12/12/2014

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Input Voltage Failure Indicator

MP2187 has input voltage failure indicator

function. There is an external resistor network

connect PFS (power fail sense) from VIN, when

PFS is lower than Power-Fail Falling threshold

(typically 0.588V), the PFL will be pulled to

ground by an internal MOSFET.

Current limit

The MP2187 has a 5.3A current limit for the

high side switch (HS-FET). When the HS-FET

hits its current limit, MP2187 enters hiccup

mode until the current drops to prevent the

inductor current from rising and possibly

damaging the components.

Short Circuit and Recovery

The MP2187 also enters short-circuit protection

(SCP) mode when it hits the current limit, and

tries to recover from the short circuit by entering

hiccup mode. In SCP, the MP2187 disables the

output power stage, discharges a soft-start

capacitor,

and

then

enacts

a

soft-start

procedure. If the short-circuit condition still

holds after soft-start ends, the MP2187 repeats

this operation until the short circuit ceases and

output rises back to regulation level.