cancel
Showing results for 
Search instead for 
Did you mean: 

TVREFINT Internal reference startup time - - 2-3 ms

CDesh
Associate III

Hi,

From the data sheet of STM32L072xx it is mentioned that Tvrefint start up time is 2-3msec. When using Vrefint in comparator, does controller take 2-3msec each time to compare input with Vrefint or it is just the initial start up time?

Because I have been observing that though the Vrefint is always enabled, comparator is taking 3-4msec each time to compare input with Vrefint.

Please clarify.

----------------------------------------------------------------------------------------------

TVREFINT Internal reference startup time - - 2 3 ms

4 REPLIES 4

> comparator is taking 3-4msec each time to compare input with Vrefint.

How exactly do you measure that?

JW

CDesh
Associate III

I am giving input signal of 4msec duration, below which the comparator is not comparing with Vrefint.

So the comparator takes 3-4msec each time to compare? Kindly confirm, how do you say so?

Do you change the COMP configuration dynamically, i.e. during the run of the program?

What is the content of REF_CFGR3 and PWR_CR registers?

Do you use some of the low power modes?

JW

CDesh
Associate III

Yes, I am enabling comparator during MCU start-up and triggering signal of 3-4msec duration in SLEEP mode. Please note that I am not disabling comparator and it is ON forever once the MCU is started.

SYSCFG_CFGR3_VREFINT_RDYF - 40000000

PWR_CSR_VREFINTRDYF - 8

PWR_CR_UPL - 200