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pv_delfa
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Hello together,

I am facing some problems with the CY8C4045LQI-S411 IDAC. If I set the range to "RNG_152_4UA" or "RNG_304_8UA" I get the same output resoltion in meanings of Microampere/LSB. The reolution was measured by setting a defined current and charging the same capacity for the same time. So the Voltage of the capacitance (max 4 V using a supply voltage of 5 V) is giving me an indicator for the used current.

The current range is changed using the standard API function of the IDAC component. I checked the "IDAC_Control_Reg" using a constant setting of 6 LSB:

RNG_76_2UA: 0x0340 0x017F

RNG_152_4UA: 0x01C0 0x017F

RNG_304_8UA: 0x0180 0x017F

As I see changes in the upper word, I expect that the range has changed. But the charging behavior of my capacity doesn't change as described, so the effective current is the same. As mentioned, this only happens with the RNG_152_4UA/RNG_304_8UA, all other ranges are working fine.

Calculating the effective current backwards from charging time, capacitance and voltage gives me the resolution of "RNG_304_8UA", so it looks like the devices uses this in both range settings.

 

Questions:

1.) Is there a description of the "IDAC_Control_Reg" available for the PSOC4000S devices? I din't find it in the register TRM "002-10099 Rev. *E"

2.) Any idea what is going wrong here? Is there any known bug according the two mentioned ranges in the PSOC4000S devices?

Thanks a lot for your help!

Pascal

 

Edit: Heading changed to be more precise

 

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MotooTanaka
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Distributor - Marubun (Japan)
First comment on blog Beta tester First comment on KBA

Hi,

Just FYI, I also checked "PSoC 4100S Plus PSoC 4 Registers Technical Reference Manual (TRM) .. Rev.C"

There CSD_IDACA : Range 0x3: IDC_MED2: 1 LSB = 1200 nA

002_CSD_IDACA_4100S_Plus.JPG

Where In the "PSoC 4000S Family PSoC 4 Registers Technical Reference Manul (TRM) ... Rev. C"

There CSD_IDACA : Range 0x3 is NOT specified.

So it may be reasonable to read that PSoC 4000S family IDAC does not support 0x3: 1 LSB = 1200 nA"

001_CSD_IDACA.JPG

moto

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MotooTanaka
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Distributor - Marubun (Japan)
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Hi,

I refered my "Rev *C" so the information may be different from yours.

The IDACs in PSOC 4000S are part of CSD component, so they are named

CSD_IDACA and CSD_IDACB.

001_CSD_IDACA.JPG

As usual, if I'm totally out of point, I'm sorry.

moto

P.S. For your reference, attached is the Rev.C 

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pv_delfa
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Thank you very much for the reference!

To be honest, now I am a little bit confused. The Datasheet of the IDAC says there are 7 current ranges existing, also for each range there is a macro defined.

If I check the register description only 6 of these 7  ranges are possible (3 Current resolutions multiplied with 2 leg configurations). Also there is no value 0x3 for the RANGE which is set if using the macro "IDAC7_1_RNG_152_4UA" for the range 1.2 uA/LSB. (The Macro gives a value of "0x0111" which is shifted by 22 so that LEG2_EN = 0; LEG1_EN = 1; RANGE = 0x11). From the register description I cannot really understand how 1.2 uA/LSB could be realized.

Is this range 1.2 uA/bit really existing? Could some official help to clarify?

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MotooTanaka
Level 9
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Distributor - Marubun (Japan)
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Hi,

As we see, these information have been intentionally removed in the current document.

I'm afraid that the answer to the question below would be no.

Is this range 1.2 uA/bit really existing? Could some official help to clarify?

If you have your official Infineon distributor, may be you can ask the representive for help.

I'm sorry for not being helpful.

moto

 

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pv_delfa
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Ok, I will try to get an answer.

 

For you information and if maybe someone else is reading this, I checked another PSoC from the 4100S PLus Series (CY8C4145LQI-PS433) which we used in the past for some measurements where we characterized also the different ranges. There all 7 ranges are working. So this seems not to be consistent between the families.

For sure it is still not understood how the range 1.2 uA/bit is realized (the code is the same also for the 4100PS)

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MotooTanaka
Level 9
Level 9
Distributor - Marubun (Japan)
First comment on blog Beta tester First comment on KBA

Hi,

Just FYI, I also checked "PSoC 4100S Plus PSoC 4 Registers Technical Reference Manual (TRM) .. Rev.C"

There CSD_IDACA : Range 0x3: IDC_MED2: 1 LSB = 1200 nA

002_CSD_IDACA_4100S_Plus.JPG

Where In the "PSoC 4000S Family PSoC 4 Registers Technical Reference Manul (TRM) ... Rev. C"

There CSD_IDACA : Range 0x3 is NOT specified.

So it may be reasonable to read that PSoC 4000S family IDAC does not support 0x3: 1 LSB = 1200 nA"

001_CSD_IDACA.JPG

moto

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pv_delfa
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Moto-san,

thank you very much for this detailed information.

Yesterday evening I checked again the manual of the IDAC component and I have to apologize: There is a notice that the number of ranges is different, not very specific but it is mentioned:

"Note Some PSoC 4100S devices have an enhanced version of the CapSense block, which includes an additional 1.2 uA/bit current range and improved performance on the VDDA voltage below 2 V." (from: Document Number: 002-20200 Rev. *A)

My fault that I did not recognize this before.

So I think this understood, we have to take care which device is used and change our configuration software. As the ranges have quite big overlapping regions it is not really a technical problem.