NCP45540

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11

Thermal Shutdown

The thermal shutdown of the NCP45540 devices protects

the part from internally or externally generated excessive

temperatures. This circuitry is disabled when EN is not

active to reduce standby current. When an over−temperature

condition is detected, the MOSFET is immediately turned

off and the load bleed is activated.

The part comes out of thermal shutdown when the

junction temperature decreases to a safe operating

temperature as dictated by the thermal hysteresis. Upon

exiting a thermal shutdown state, and if EN remains active,

the MOSFET will be turned on in a controlled fashion with

the normal output turn−on delay and slew rate.

Undervoltage Lockout

The undervoltage lockout of the NCP45540 devices turns

the MOSFET off and activates the load bleed when the input

lockout threshold. This circuitry is disabled when EN is not

active to reduce standby current.

threshold, and EN remains active, the MOSFET will be

turned on in a controlled fashion with the normal output

turn−on delay and slew rate.

W

Bandgap

&

Biases

Charge

Pump

Delay and

Slew Rate

Control

Thermal,

Undervoltage

&

Short−Circuit

Protection

Control

Logic

Load

Controller

3.0 V − 5.5 V

Power Supply

or Battery

0.5 V − 13.5 V

Figure 30. Typical Application Diagram − Load Switch

100 k