TLV62130 - 1. EN pin, does it have hysteresis; 2. Input voltage to the TLV62130 ramps up very slowly, is this a problem?

Kenneth Aquino

Other Parts Discussed in Thread: TLV62130, TPS62125

Hi,

I'm using the TLV62130 to produce +5 volts at a modest 300 mA output current. Just in front of the TLV62130 I have four 0.47 Farad (yes, Farad) capacitors, with ESR of 1 Ohm max, in series (total capacitance = 0.11 Farads). The automotive +12 volt battery is switched to the capacitors via a FET. The FET has an rds-on of about 3 Ohms. The time constant is therefore about 330 ms, the time for the input voltage to get to about 6 volts is maybe two time constants, or 660 ms. Is this too long a rise time for the input voltage to the TLV62130?

My other question is about the "EN" pin. The data sheet says that the Vin HI theshold min is 0.9 volts and the Vin Lo threshold max is 0.3 volts. This is not a Schmitt trigger input, is it?

Regards,

Ken

over 9 years ago

0 Chris Glaser over 9 years ago

TI__Guru*** 142750 points

The slow rise time is not a problem. But if you tie EN to Vin through a voltage divider, you will likely see a rather wide range of voltages at which it turns on due to the wide gray area of the EN pin. The point at which EN goes from low to high can be anywhere between 0.3V and 0.9V. For accurate turn on at a specific voltage, you should use an additional SVS.

The TPS62125 includes such an SVS and is likely a better solution for your application.

0 Kenneth Aquino over 9 years ago in reply to Chris Glaser

Expert 1300 points

Chris,

Thank you very much.

Ken

Power management

Power management forum

TLV62130 - 1. EN pin, does it have hysteresis; 2. Input voltage to the TLV62130 ramps up very slowly, is this a problem?