Tracking regulator required

Joerg Schreiner

Dear Experts,

to support a MSP430 with dual supply we need to find a solution so that both voltages (5V and 3.3V) are powering up close to each other i.e. the voltage difference while powering up must not be bigger than ~0.3V. Input voltage is 12V. Output currents are in the "mA"-range.

Thanks a lot and regards

Joerg

over 14 years ago

0 Chris Glaser over 14 years ago

TI__Guru**** 150770 points

We have several 'high-voltage' (12V) linear regulators to choose from at power.ti.com. Keep in mind the power dissipation if the currents get higher than a few mA.

Would a diode from 3.3V to 5V be acceptable? Then the 3.3V would be turned on first and after it is in regulation, the 5V would turn on.

0 Chris Glaser over 14 years ago in reply to Chris Glaser

TI__Guru**** 150770 points

Were you able to find a solution?

0 Joerg Schreiner over 14 years ago in reply to Chris Glaser

TI__Intellectual 2400 points

No - I had hoped to be pointed to a specific device or a solution how to make sure the voltages track.

0 Chris Glaser over 14 years ago in reply to Joerg Schreiner

TI__Guru**** 150770 points

Yes, and I recommended a solution to meet your 'both voltages need to be within 0.3V of each other during start-up' question. A diode from the lower voltage to the higher voltage will provide this. Is this acceptable?

We don't have a 1 chip LDO that can operate from 12V and give 5V that supports tracking.

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Tracking regulator required