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simonlasnier
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Running DA14531 @3.3V

Hi again :) 

In the datasheet I can see the DA14531 chip should ideally be run at 3V (=typical value, 3.3V being the max value). But looking at the schematics of the USB development board it seems the output of a 3.3V LDO (NCP114ASN330T1G) it sent directly to the VBAT_HIGH pin, and I see no level shifter for the digital signals (which are sent from the other MCU running @3.3V).

So I am only asking to be sure - but I guess it is possible to use it the same way we would use a 3.3V MCU?

Thank you

Simon

PM_Dialog
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Hi simonlasnier,

Hi simonlasnier,

Thanks for the follow up forum post. To be honest, I am not completely sure if I understood your question correctly. Are you asking about a custom board design? Could you please clarify it?

Thanks, PM_Dialog

simonlasnier
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Simply put: it seems the chip

Simply put: it seems the chip is made to run at 3.0V, is it possible to run it at 3.3V (even though it is on the "max" value in the datasheet)?

My guess will be yes since you guys do it in the USB demo board - can you confirm?

PM_Dialog
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Hi Simon,

Hi Simon,

Please check the HW design guidelines document :

https://www.dialog-semiconductor.com/sites/default/files/an-b-075_da14531_hardware_guidelines_1v3_0.pdf

VBAT_HIGH voltage is in the range of 1.8 V – 3.3 V. This power rail is used for the blocks that require a higher supply voltage. The OTP and the GPIOs are connected to this power rail. The lowest voltage for OTP reading is 1.62 V (or 1.75 V in Bypass mode) whereas to write OTP this is 2.25 V.

You can also refer to the datasheet.

Can I ask if you are planning to use DA14531 or the 531 TINY module? Are you planning to create a custom board?

In general the DA14531 can be configured in buck, boost or bypass configuration

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simonlasnier
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Hi :) 

Hi :) 

Thanks for the answer. For now I am using the TINY module but eventually will probably use the DA14531 directly.

I read throught the power section of the hardware guidelines. My project will already have another MCU running from a 3.3V rail. So my idea was to spare an extra LDO and connect both pins VBAT_HIGH and VBAT_LOW to the 3.3V rail, in bypass configuration.

I know this is within the range of 1.8 - 3.3V, but on the edge, so I wanted to make sure it was still ok.

PM_Dialog
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Hi Simon,

Hi Simon,

Please see Table 3: Recommended Operating Conditions in the module datasheet. It is up to 3.3V – but I will ask internally to make sure.

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simonlasnier
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That would be great thank you

That would be great thank you :) 

PM_Dialog
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Hi Simon, 

Hi Simon, 

According to datasheet, the Operating range if from 1.8 V to 3.3 V, so yes you can do it. Please see the datasheet.

Thanks, PM_Dialog

simonlasnier
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Yes I saw that in the

Yes I saw that in the datasheet as already mentioned above. I will take this as confirmation then ;)