PCM6260-Q1: Please recommend the level conversion chip applicable to TDM: 1.2 V → 3.3 V, rate 50 MHz，bidirectional

Hi Ruben,

PCM6260 supports single supply I/O operation at 1.8V or 3.3V.

The maximum source clock that can be provided to the device, BCLK or MCLK, is 24.576MHz. Section 8.3.2 of the PCM6260 d/s outlines the supported FSYNC/BCLK ratios the user can provide. Therefore, this device will not fit customer application

I am reassigning this thread to the team who supports the SN7 device

Hi Daveon,

Thank you very much for your help.

Hi Josh，

Yes，bi-directional means auto-sensing.Is there a bidirectional level conversion chip that can support supply voltages from 1.1V to 5.5V and operates at 50MHz?

Thanks.

Hello Rubin,

From my understanding, TDM is a fixed direction signal. We don't recommend using auto-sensing devices on fixed signals due to the lack of drive strength. Auto-sensing devices are better suited for interfaces like I2C

I would still recommend using the LXC2T45-Q1

Regards,

Josh

Hi Josh，

Can A→B be applied only when the voltage of DIR is equal to or greater than half of the voltage of VCCA?
Is there any reference design for SN74LXC2T45-Q1?

Thanks

Hi Josh,

I use SN74LXC8T245QDCURQ1 to perform I2S_BCLK level conversion (the hardware topology is shown in the following figure). The voltage is converted from 1.2 V to 3.3 V, and four rates are converted from 6M, 12 M, 24 M, and 36 M (the verification result is shown in PDF).
As the rate increases, overshoot and undershoot become more serious.

Could you please check whether there are optimization suggestions on overshoot and undershoot?

Thanks

Test Waveform.pdf

Hello Rubin,

Two things that come up

1) Trace impedance is not matching device output impedance. When impedances don't match, you see poor signal integrity at higher frequencies

2) Scope probes. With high frequencies, we need to make sure active probes are used. Tip and barrel would also work.

Regards,

Josh

Hi Josh,

If VCCA=1.2V,VCCB=5V,and I want A→B.In this case,the voltage of DIR should be higher than (?) V.

If VCCA=5V,VCCB=1.2V,and I want A→B.In this case,the voltage of DIR should be higher than (?) V.

Thanks

Hello Rubin,

DIR and OE pins are always referenced to VCCA. Given this information:

1) 1.2V or higher

2) 5V

Regards,

Josh