AMC1210: AMC1210's SPI Communication malfunction

Isao Konishi

Prodigy 10 points

Part Number: AMC1210

Dear TI support,

I'm designing the AMC1210 and AMC1106M for Thermal Coupling sensor. Designing of AMC1210 is with

SPI communication with 4MHz on SPI-1. And, Power supplys are, 5V: AVDD, 3.3V:BVDD,CVDD and DVDD,

GND: AGND. Other pins are TE,M0,M1 for GND. SH1,SH2 pulled down with 10K ohm. CLK is 24MHz.

*WR is connected with SPICLK. *RD is connected with MOSI. AD0 is connected with MISO. And, *CS

is connected with GND for this board's SPI device is only AMC1210.

But MISO is LOW only.

I found CLK waveform is bad. I used KC2520Z24.0000C14Y00 with 15pF available.

So, if it caused this issue,

1. Teach AMC1210'S CLK pin capacitance.

2. AMC1210 SPI communication stop condition.

over 1 year ago

0 Alexander Smith over 1 year ago

TI__Guru 50981 points

Hi Konishi-san,

Can you please provide a schematic and oscilloscope captures showing the design and SPI communication signals?

0 Isao Konishi over 1 year ago in reply to Alexander Smith

Prodigy 10 points

OK. My Schematics is below.

And, SPI communication waveform is below. When it is read command for 0x21 register.Ch.1 is SPICLK, Ch.2 is MOSI.

on this picture, it is timing for sampling and shifting.

It is CLK for Pin16 on AMC1210.

MISO is no work. Can you help my design problem?

0 Alexander Smith over 1 year ago in reply to Isao Konishi

TI__Guru 50981 points

Hi Konishi-san,

I agree that the clocking signal is bad and is likely not able to operate and output data as a result.

If BVDD is 3.3V, then V_IH = 2.31V and V_IL = 0.99V.

Your clocking signal's peaks do meet these requirements, 2.37V and 0.98V respectively, but the device may be latching at a time other than the peak and not meeting the V_IH and V_IL requirement.

As the clock is not a TI product, the support I can offer is limited, but a series resistor in the clock line may help.

0 Isao Konishi over 1 year ago in reply to Alexander Smith

Prodigy 10 points

Hi Smith-san,

Thanks for your advice. I'll try it.

And, in my first questions, can you teach AMC1210's Input capacitance?

0 Alexander Smith over 1 year ago in reply to Isao Konishi

TI__Guru 50981 points

Hi Konishi-san,

Apologies for not addressing this question in my previous responses. Unfortunately this data is not available. This is an older device and the team that designed it is no longer with the company. The available information is limited to what is in the datasheet.

0 Isao Konishi over 1 year ago in reply to Alexander Smith

Prodigy 10 points

Hi Smith-san, thanks for your reply. And, I understand for this information.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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AMC1210: AMC1210's SPI Communication malfunction