MPQ5073

– 5.5V, 2A LOW RDSON LOAD SWITCH WITH PROGRAMMABLE CURRENT LIMIT, AEC-Q100 QUALIFIED

MPQ5073 Rev. 1.01

www.MonolithicPower.com

11

10/26/2016

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APPLICATION INFORMATION

ILIM Resistor Selection

The current limit value can be set by ILIM

resistor. The current limit can be gotten by

equation (1).

The current limit threshold is suggested to 10%

~ 20% higher than maximum load current. For

example, if the system’s full load is 2A, set the

current limit to 2.2A.

ILIM Capacitor Selection

The internal advanced auto-zero comparator

bring a high accuracy of current monitor. The

auto-zero will also cause some little jitter on

ILIM pin. To get a more stable ILIM, a small

ceramic capacitor can be mounted between

ILIM and ground. Suggested place an ILIM

capacitor less than 1nF.

Soft Start Capacitor Selection

There is an internal 11µA constant current

source charge SS cap and ramps up the

voltage on the SS pin. The output voltage rises

follow the slew rate of SS voltage.

If the inrush on output current reached the

current limit during start up (like with large

output cap or very large load), MPQ5073 will

limit the output current and the same time, SS

time will be increased (Fig 2 and Fig 3).

Component Selection

Soft Start @ Different Load

Soft Start @ No Load

Soft Start @ Half Load

Soft Start @ Very large Load

Current Limit

Current Limit

Current Limit

Figure 2: Soft Start Periods at different load