MPQ5072

– 5.5V, 1A LOW RDS(ON) LOAD SWITCH, AEC-Q100 QUALIFIED

MPQ5072 Rev. 1.0

www.MonolithicPower.com

11

10/16/2020

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APPLICATION INFORMATION

ILIM Resistor Selection

The current limit value is set by the ILIM resistor

(RILIM). The current limit can be calculated with

Equation (1) on page 10.

The suggested current limit threshold should be

10% to 20% greater than the maximum load

current. For example, if a

system’s full load is 1A,

set the current limit to 1.1A.

ILIM Capacitor Selection

The internal, advanced, auto-zero comparator

offers high-accuracy current monitoring, though

it causes a small amount of jitter on the ILIM pin.

To stabilize ILIM, mount a small ceramic

capacitor between the ILIM pin and GND. It is

recommended to use a capacitor that is less than

1nF.

SS Capacitor Selection

An

internal

11µA

constant-current

source

charges the SS capacitor, which ramps up the

voltage on the SS pin. The output voltage follows

the SS voltage slew rate as it rises.

If the inrush of the output current reaches the

current limit during start-up (e.g. if there is a large

output capacitor or a large load), the MPQ5072

limits the output current, and the soft-start time

increases simultaneously (see Figure 2 and

Figure 3).

Component Selection

VOUT

IIN

Current Limit

Soft Start at No Load

Soft Start at Half-Load

Soft Start at Very Large Load

Soft Start at Different Loads

VOUT

IIN

Current Limit

VOUT

IIN

Current Limit

Figure 2: Soft Start at Different Loads