MSP430FR5969: MSP-EXP430FR5969 crystals selection

Hi,

I don't know which datasheet to find the msp430 crystal oscillator. Would you please to tell me?

Thanks

zzx

The BOM ("Download Hardware Design Files" on the Product page) suggests the ECS-40-20-1X, Digikey part X971-ND:

https://www.digikey.com/products/en?keywords=x971-nd

This is a 4MHz crystal (in kind of a tall package). There are probably HC-49 variants in different speeds (and heights).

/cfs-file/__key/communityserver-discussions-components-files/166/MSP_2D00_EXP430FR5969_2D00_bom.xls

Bruce McKenney47378 said:

The BOM ("Download Hardware Design Files" on the Product page) suggests the ECS-40-20-1X, Digikey part X971-ND

If I have a Y1 crystal which is not 4MHz, then how to choose  C3 and C4 fitted Y1 ?

user5343784 said:

If I have a Y1 crystal which is not 4MHz, then how to choose  C3 and C4 fitted Y1 ?

Would you please tell me what this formula is or where to find it? Thanks ! :)

I'm sure Google will help you find the formula.

Alternatively, you can choose one of the (maybe 15) crystal speeds that DigiKey lists in that product line, all of which appear to be 20pF. Or use their product filters to find an HC-49 crystal at 20pF from someone else. Then you don't need the formula at all.

What are your specifications?

https://www.digikey.com/products/en/crystals-oscillators-resonators/crystals/171?FV=-5%7C8764%2C35%7C143603%2C-8%7C171&quantity=0&ColumnSort=0&page=1&pageSize=25

1）This link is the oscillator that i want to use. Do they meet the requirements？

2）Besides，the datasheet says "Up to 16-MHz system clock and 8-MHz FRAM access".  And another place says "Y1: an unpopulated region that supports HF crystal or resonator (4 to 24 MHz)" .

Does this mean the max frequency is 16MHz?  Are there any other restrictions?

Thanks.

1) I see HC-49/U package and 20pF capacitance, so I expect any of those would work using the capacitors mentioned in the BOM.

2) The data sheet (SLAS704F) Table 5-5 says the MCU's HF oscillator can run at 24MHz, but footnote (3) says you can't exceed the max speed (MCLK usually) for the device. That max is given in Sec 5.3 as 16MHz. So in theory, you could use a 24MHz crystal but you'd have to divide it down to <= 16MHz. Since you only get integer dividers, that means with a 24MHz crystal the fastest you could run is 24/2=12MHz. (No, I'm not quite sure why someone would do that.) I recommend sticking with crystals <= 16MHz.

Don't forget to set NWAITS=1 (before switching the clock) if you pick something > 8MHz.