5V LDO on 5V input voltage

[kristaps_r]

Hi guys.

I have situation where mu circuit is used with power sources usually rated at 5V. They give out something like 5.2V. But there are also 6V regulators that people want to use.
I have ICs that handle 3.6V - 5.5V. They also work on 6V but I want to make some protection to be correct with voltages.

So question is:
Can I use 5V LDO for protecting ICs?
How will work LDO regulation if input voltage will be 5V?
Will output voltage drop to something like 4.8V that is OK for ICs and everything will be OK or working in Dropout is not OK and I have to use 4V LDO by example?

Regards,
Kristaps

 

[tpetar]

Yes, you can use LDO regulator, even zener diode will do the job.

ADP667ARZ - Voltage stabiliser: LDO, adjustable; 5V; 250mA; SO8
https://www.tme.eu/en/Document/25c30546dfef3a5b5f29cf095331df92/adp667arz.pdf
Low-Dropout: 150mV @ 200mA
Low Power CMOS: 20μA Quiescent Current
Shutdown Mode: 0.2μA Quiescent Current

 

[kristaps_r]

Thanks.
Still thinking is there any changes in operation when using LDO in dropout state. Maybe less current ...
I am thinking to use MIC5205-4.0YM5 not to operate in dropout, but I used internal reference for ADC 4.096V I think it will be OK to use stabilised 4V.

 

[tpetar]

Dont worry IC will nicely work on 5V, in datasheet you can check that probably 5,5V is maximum working voltage, and absolute maximum voltage is 6-6,5-7V.

 

[sivamani]

check the min operating voltage of your IC.