MP5092 – DUAL 5.5V, 7.5A LOW RDSON LOAD SWITCH WITH OUTPUT DISCHARGE FUNCTION
MP5092 Rev. 1.0 www.MonolithicPower.com 13
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© 2015 MPS. All Rights Reserved.
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 7A, set the
current limit to 7.7A.
ILIM Capacitor Selection
The internal advanced auto-zero comparator
bring a high accuracy of current limit. 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 a ILIM capacitor less
than 1nF.
Soft Start Capacitor Selection
There is an internal 9uA constant current
source charge SS cap and ramps up the
voltage on the SS pin. The output voltage rises
follow 3 times 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), MP5092 will limit
the output current and the same time, SS time
will be increased (Figure 2).
Soft Start @ Different Output Capacitance
V
OUT
Soft Start @ Small Capacitance
Soft Start @ Large Capacitance
I
IN
V
OUT
I
IN
V
OUT
I
IN
Soft Start @ Very large
Capacitance
Current Limit
Current Limit
Current Limit
Figure 2: Soft Start Periods at different output
capacitance
