topic Re: What does TPL stand for? in Power Management

What does TPL stand for?

fab_ — Mon, 09 Dec 2019 19:59:47 GMT

By the products of MC33664 and MC33771/2 NXP offers its own communication bus to connect the components in daisy chain. I'm constantly asking myself, what does TPL stand for. I couldn't find a precise answer in your data sheets.

Re: What does TPL stand for?

TomasVaverka — Wed, 11 Dec 2019 09:38:23 GMT

Hi Fabian,

TPL stands for transformer physical layer.

The MC33771/MC33772 (battery cell controller) and MC33664 (TPL transceiver) communication solution is based on a passive electrical bus (no repeater, no amplifier).
High-speed differential isolated communication is achieved through the use of transformers.

The benefits of such a solution are:
• more robust Electromagnetic Compatibility (EMC) characteristics (intrinsic transformer
common mode rejection)
• greater high-voltage isolation
• better communication speeds and synchronized measurements
• lower cost

The picture below illustrates how the MC33664 TPL transceiver exchanges data between the MCU and the MC33771.

First, you can notice that the MCU needs two SPI ports for the SPI to TPL translation; one for MOSI and one for MISO. At the top of the waveforms, the MCU is going to initiate a command to the MC33771. CS1\ being asserted by the MCU causes a start of message double positive pulse on the TPL bus. This double pulse in turn causes CS2\ to be asserted on the MC33664. This starts the process of the command message from the MCU to be echoed back to the MCU on the MISO pin. After the start of message double pulse, data is clocked out of MOSI and translated onto the TPL bus. The signal on the TPL bus is a differential sine wave. The phase of the sine wave dictates whether it is a one or a zero. After the MOSI data is completed, CS1\ is de-asserted by the MCU and this causes an end of message double negative pulse. After the MC33771 processes the command, it then initates putting it is response data on the TPL bus. The reverse process occurs where the start of message double pulse on the TPL bus is translated to by the MC33664 and it asserts the CS2\ pin on the MCU so it can now receive data on MISO.

I hope it clarifies your question. Let us know if you need any further information.

Best regards,

Tomas

PS: If this answer helps to solve your question, please mark it as "Correct" or “Helpful”. Thank you.

Re: What does TPL stand for?

fab_ — Wed, 11 Dec 2019 10:43:51 GMT

Hi Thomas,

thanks for the fast and detailed response. Your answer is very helpful. Thanks!

Best regards,

Fabian

Re: What does TPL stand for?

michael_liu_liu — Wed, 19 Apr 2023 03:53:23 GMT

hi,Tomas

TPL transceiver look like CAN FD protocol? Is there bit time ? is there a sample point ? what's the speed?

Re: What does TPL stand for?

michael_liu_liu — Mon, 19 Jun 2023 08:56:33 GMT

Tomas

but ,33771 is slave , reponse sclk was generated by 33771?

Regards

Michael

Re: What does TPL stand for?

michael_liu_liu — Mon, 19 Jun 2023 08:57:24 GMT

but ,33771 is slave , reponse sclk was generated by 33771?

Re: What does TPL stand for?

Patrick_Pavle — Wed, 01 May 2024 17:52:33 GMT

Hello @TomasVaverka,

is this also described in any data sheet that the MC33664 generates an echo?

BR, Patrick