MP2145

– 5.5V, 6A, 1.2MHz, COT, BUCK SWITCHER

MP2145 Rev. 1.11

www.MonolithicPower.com

15

12/20/2016

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Power-Good Indicator

The MP2145 has an open drain with a

500kΩ

pull-up resistor as a power-good (PG) indication.

PG is pulled up to VIN when the FB voltage is

within 10% of the regulation level.

Otherwise

the PG pin is pulled to ground by an internal

of less than 100Ω.

Current Limit

The MP2145 has a 8.1A current limit for the

HS-FET. When the HS-FET hits its current limit,

the MP2145 enters hiccup mode until the

current drops to prevent the inductor current

from

rising

and

possibly

damaging

the

components.

Short Circuit and Recovery

The MP2145 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 MP2145 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 MP2145 repeats

this operation until the short circuit ceases and

output rises back to regulation level.

100% Duty Cycle Mode

When the input voltage reduces and is lower

than the regulation output voltage, the output

voltage drops, and the on time increases.

Further reducing the input voltage drives the

MP2145 into 100% duty cycle mode. The high-

side switch is always on, and the output voltage

is determined by the loading current times the

inductor.