MSP430FR2433: About the method of DCO optimization in extremely cold environment

Cruijff

Part Number: MSP430FR2433

Hi community member,

I have the following questions about the "DCO" and "FLL" of MSP430FR2433 .

<Background>
The customer's application is considered to be used from normal temperature environment to extremely cold environment (around -30°C).
Since the environmental temperature changes, DCO software trim is implemented. (Refer to msp430fr243x_cs7.c)

However, when the MSP430FR2433 is active mode from reset state in a very cold environment (around -30 ° C), the DCO tap will reach the maximum value of 511 at DCO initialization.

When the MSP430 runs in Active mode at all times, what is the recommended frequency of software trimming for the DCO?
Please tell me the best initialization method when releasing the microcomputer reset under extremely cold environment.
In a very cold environment, is it also necessary to change DCORSEL?

It is set as follows in DCO initialization.

DCO frequency: 4.9125 MHz
DCORSEL: 2
DCOFTLIM: 4

Best regards.
Cruijff

over 5 years ago

0 JD Crutchfield over 5 years ago

TI__Mastermind 27240 points

Hello Cruijff,

1. If you're always running in active mode, I don't think you need to run the software trimming extremely often. I think once every few seconds with plenty fast enough. Especially if the temperature is changing very slowly.

2. I'm not aware of any differences needed at -30C. Wei provides the recommended process to configure the FLL here: https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/639224?MSP430FR4133-DCO-set-6MHz-with-FLL

3. If DCO is reaching 511, have you tried adjusting the DCOTRIM? It may give you the range you need.

Thanks,

0 JD Crutchfield over 5 years ago in reply to JD Crutchfield

TI__Mastermind 27240 points

Hello Cruijff,

I wanted to let you know that I will be traveling and unavailable for the next 10 days. I hope the above information has helped you solve your issue. If not, then I will review further when I return.

In my absence, other community members may also chime in.

Thanks,

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MSP430FR2433: About the method of DCO optimization in extremely cold environment