DIO7552B/7553B

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© 2019 DIOO MICROCIRCUITS CO., LTD

DIO7552B/7553B• Rev. 1.3

UVLO

Heavy Load to Overload

(VIN=5V,VEN=VIN,ROUT=3.9Ω,VIN→0V)

(VIN=5V,VEN=VIN,ROUT=3.3→1.8Ω)

Applicaion Information

Operation Information

DIO7552B/7553B is a current limited P-channel MOSFET power switch with over current and over temperature

protection. There is no body diode across the drain and the source of the MOSFET. It prevents the current flow

from the output to the input after the chip is disabled.

Over-current Protection

When the over-current condition is detected, the switch is regulated to achieve constant output current. If the

over current condition lasts for a long time, and results in a junction temperature over 140°C, the switch will be

shutdown. Once the junction temperature drops to 120°C, the part will restart.

Reverse-voltage Protection

The reverse-voltage protection feature turns off the P-channel MOSFET whenever the output voltage exceeds

the input voltage by 135mV (typ) for 4ms (typ). A reverse current of (VOUT-VIN)/RDS(on) will be present when this

occurs. This prevents damage to devices on the input side of the DIO7552B/53B by preventing significant current

from sinking into the input capacitance. The DIO7552B/53B devices allow the P-channel MOSFET to turn on

once the output voltage goes bellow the input voltage for the same 4ms deglitch time.

Supply Filter Capacitor

In order to prevent the input voltage from dropping during hot-plug condition, a 10µF ceramic capacitor from VIN

to GND is strongly recommended. However, higher capacitance could help reduce the voltage drop. Furthermore

an output short will cause ringing on the input without the input capacitor. It could destroy the internal circuitry

when the input transient voltage exceeds the absolute maximum supply voltage even for a short duration.

Current Limiting Setting

Current limit is programmable to protect the power source from over current and short circuit conditions. Connect

a resistor RSET from ISET pin to GND to program the current limit:

IOS (A)=25752/Rset(Ω).

The minimum current limit is 0.4A. Current limit beyond 2.57A is not recommended.

VIN

VOUT

Flag

IOUT

Flag

VOUT

IOUT