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ADP198 Reverse Current Blocking Response Time

Question asked by rpmarchand Employee on Jun 11, 2014
Latest reply on Aug 15, 2014 by gmorita

Hello,

 

I have been looking at the ADP198 - 1A high side load switch with reverse current blocking - and i see that there is a specification for the hysteresis for when the reverse current protection is active (75mV typical).  I also read the description in the datasheet that clearly states how this achieved:

 

The reverse current protection circuitry prevents current from flowing backwards through the ADP198 when the output voltage

is greater than the input voltage. A comparator senses the difference between the input and output voltages. When the difference between the input voltage and output voltage exceeds 75 mV, the body of the PFET is switched to VOUT and turned off or opened. In other words, the gate is connected to VOUT.


What I would like to know is if you have characterized or can provide some guidance on the response time of the reverse current protection under the following conditions:


1. From a power up event where Vout is applied before Vin (i.e. Vout = 5V and Vin = open with a 500ohm to ground resistor externally in the system, EN = open).  What would the response time of the reverse current protection be in this case?

 

2. When Vin is already present and a higher voltage is applied to Vout (i.e. Vout = 5V, Vin = 3.7V, EN = low).  Is the response time of the reverse current blocking different than the first case? 

 

Any insight would be greatly appreciated!   

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