52820 LPCOM problem

RE: 52820 LPCOM problem

Jørgen Holmefjord — Mon, 08 Feb 2021 09:28:50 GMT

Hi,

The peripherals are not defined inside PRS, the PRS (Peripheral Resource Sharing) library is used to manage shared resources in the chip. For the COMP peripheral, this means allowing COMP and LPCOMP to be used from the same application, while preventing both from being initialized at the same time. Since nRF52820 does not include a LPCOMP peripheral, there is no need to add COMP to PRS.

NRF_COMP is defined in nRF5_SDK_17.0.2_d674dde\modules\nrfx\mdk\nrf52820.h:2056.

Can you post the code you used for configuring and initializing the COMP peripheral?

Best regards,
Jørgen

RE: 52820 LPCOM problem

zero — Mon, 08 Feb 2021 03:54:59 GMT

Hi Jørgen,

I added the COMP code on sdk17.0.2 and ran it on 52820, but I saw that the interruption had no effect. Check the nrfx_prs.h file. NRF_COMP is not defined on 52820.

What should I do to use interruption?

Best regards,
Zero

RE: 52820 LPCOM problem

Jørgen Holmefjord — Thu, 28 Jan 2021 09:48:43 GMT

[quote user="zero"]1. If COMP is set to low power mode, what is the difference with LPCOMP?[/quote]

Like I said, these are two separate peripherals, with different feature set. COMP will still have the same features, regardless of the configured mode. The mode will affect the propagation delay, causing slower response time. See COMP Electrical Specification for details on this.

[quote user="zero"]2. Can COMP be set to low power to wake up the chip?[/quote]

No, this is a feature of the LPCOMP peripheral only, it is not available from COMP peripheral.

[quote user="zero"]3. COMP is set to low power mode. Is the power consumption of COMP consistent with that of LOPCOM?[/quote]

No, you can compare the current consumption of the two peripherals in the nRF52832 PS chapters COMP Electrical Specification and LPCOMP Electrical Specification.

RE: 52820 LPCOM problem

zero — Thu, 28 Jan 2021 02:35:58 GMT

Hi Jørgen,

Thanks for your help, but I still have the following questions:
1. If COMP is set to low power mode, what is the difference with LPCOMP?
2. Can COMP be set to low power to wake up the chip?
3. COMP is set to low power mode. Is the power consumption of COMP consistent with that of LOPCOM?

Best regards,
Zero

RE: 52820 LPCOM problem

Jørgen Holmefjord — Wed, 27 Jan 2021 13:53:39 GMT

Hi,

There is no LPCOMP peripheral in the nRF52820, only LPCOMP is available.

The two peripherals is not identical. COMP have more steps on the reference ladder (64 vs 15 for LPCOMP), and more choices of references (including 8 external references, internal reference voltages (1.2, 1.8, and 2.4V), LPCOMP can only use a fraction of VDD as reference, or 2 external reference). COMP also supports differential mode, where you can detect small variances between two input signals.

LPCOMP can on the other hand be used to wake the chip from System OFF sleep mode, this is not possible with the COMP peripheral.

Best regards,
Jørgen