MP5086 –5.5V, 7A, LOW RDSON LOAD SWITCH WITH CURRENT MONITORING AND NTC COMPARATOR

MP5086 Rev.1.0

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11

11/6/2014

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OPERATION

The MP5086 is designed to limit the in-rush

current to the load, thereby limiting the

backplane’s voltage drop and the slew rate of

the voltage to the load. It provides an integrated

solution to monitor the output current to

eliminate the need for an external current power

MOSFET, and current switch device. It also

integrated fast short circuit protection, thermal

shutdown feature and NTC logic to set over

temperature threshold.

Operation Mode

There are four operation modes in MP5086:

normal mode, bypass mode, NTC protection

mode and transportation mode.

When EN is high and IC not trigger any

protection, IC works in normal mode. Under this

status, the main MOS, bypass MOS are always

on. Normal mode is main operation mode. The

quiescent current is about 240µA.

The bypass mode is that EN goes low and IC

not triggers any protection, it will turn off the

main MOS and disable most blocks to saving

energy. The bypass MOS is still on and it can

take <10mA load. The quiescent current of this

there will be a few µA leakage current caused

by the internal 800kΩ output sense resistor. It is

recommended adding 100Ω to 1kΩ resistor

externally.

The NTC protection mode means that the IC

detect the NTC signal goes low or trigger over

temperature protection, typically 155°C. It

shutdown the main MOS and the bypass MOS

forcedly, disable OTP pull-down MOSFET and

refresh OTP pin flag and quit this mode.

The transportation Mode means the part

shutdown all blocks and reduces the quiescent

current to lower than 1µA. When the part is in

NTC protection mode, make sure EN is lower

than 0.4V and OTP pin is lower than its refresh

voltage, typically 0.84V, the part will enter

transportation mode. Transportation mode will

the battery life.

Basic Logic

For MP5086, you can find the basic logic in

below figures. OTP is connect to external 5V

with a 100k resistor, please refer figure 5.

Figure 2: Normal Mode with external 5V

NTC protection Mode

Figure 3: Normal Mode without external 5V

NTC protection Mode

EN Restart

Figure 4: Normal Mode

NTC protection

Mode

Transportation Mode