TLIN1028-Q1: can't enter to sleep mode when EN and TXD are low

Ivy Jin

Expert 6455 points

Part Number: TLIN1028-Q1

Tool/software:

Hi team,

My customer tested TLIN1028-Q1 and met below issue, could you please give some comments?

The customer would like to change mode from normal mode to sleep mode.

The EN = Low > tEN, TXD = Low and nRST = High can be met.

1. When they pull the EN down first and the TXD down after 2us, TLIN1028-Q1 goes smoothly into sleep mode.

2. When they pull the EN down first and the TXD down after 7us, TLIN1028-Q1 can't enter into sleep mode.

May I ask what are the specific requirements for TXD and EN pull down timing, and why are these two different situations?

Thanks in advance.

Regards,

Ivy

over 1 year ago

0 Michael Ikwuyum over 1 year ago

TI__Guru 68207 points

Hi Ivy,

I believe you are referring to the t_EN spec as the data sheet species a window to sample TXD after EN is pulled and would recommend double checking practical factors in your test are not influencing the actual timing (effective timing at the device’s input pins might differ from the measured delay), and ensuring a clean signal transition with rise / fall times within recommended ranges, thanks.

Best Regards,

Michael.

0 Ivy Jin over 1 year ago in reply to Michael Ikwuyum

TI__Expert 6455 points

Hi Michael,

May I ask if there is a requirement to pull the EN down first or pull the TXD down first?

I see in below thread, Danny commented that TXD must be low before EN goes low for the device to enter Sleep mode from Normal mode.

In my customer's test, they pulled the EN down first and then the TXD down. Is it possible that this is the reason for this issue?

TLIN1028-Q1: LIN transceiver LDO power not turning off when EN and TXD is made low. - Interface forum - Interface - TI E2E support forums

Thanks,

Ivy

0 Michael Ikwuyum over 1 year ago in reply to Ivy Jin

TI__Guru 68207 points

Hi Ivy,

Unfortunately, I do not see where the data sheet recommends for TXD being low prior to EN. Note that t_en spec also indicates to change EN's state before sampling TXD. Hence, it is possible that the device only waits 3us before sampling TXD. Therefore the system needs to drive TXD low within 3us after EN is low to guarantee Sleep mode under all conditions, thanks.

Best Regards,

Michael.