TXS0104E: TXS0108E Connect TXS0104E Problem

user5861925

Intellectual 570 points

Part Number: TXS0104E
Other Parts Discussed in Thread: TXS0108E

Hi :

I would like to use TI TXS0104E and TXS0108E, please help to answer a few questions, thank you.

1.Is it ok to use two level conversion chips in series?

The operational scenario is as follows

A Board: TXS0108E&TXS0104E

B Board:TXS0104E

A Board TXS0108E A4&A5 Pin connect B board B1&B2 Pin
A Board TXS0104E A3&A4 Pin connect B board B3&B4 Pin

2.Is this series of chips suitable for serial communication? Is there any more suitable recommendation?

Sunny

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 325150 points

It is possible to uses multiple TXSes in series.

There are many protocols that are called "serial". If you have unidirectional signals, unidirectional or direction-controlled translators are usually more suitable.

0 Dylan Hubbard over 6 years ago in reply to Clemens Ladisch

TI__Mastermind 47735 points

Hi,

You can refer to the FAQ below to see our recommended devices for standard communication protocols.

https://e2e.ti.com/support/logic/f/151/t/740319?tisearch=e2e-sitesearch&keymatch=faq%3Atrue

0 user5861925 over 6 years ago in reply to Dylan Hubbard

Intellectual 570 points

Hi:

I would like to consult you on two other questions. Please help me answer them. Thank you。

1. Regarding the following description in TXS0108E specification, can you understand it as follows:

A. When A port input is low and B port output is low, Rpub=40K?

B. When A port input is high and B port output is high, Rpub=4K?

What is the value of Rpua in both cases?

2.In the process of use, sometimes the low level can not be maintained at a constant low, low level during the occurrence of similar to the shock wave clock, what may be the reason?

The following is the abnormal situation waveform of the connection point. The low level position in the figure causes oscillation：

0 Dylan Hubbard over 6 years ago in reply to user5861925

TI__Mastermind 47735 points

Hi,

The Rpua value is also stated in that excerpt. It can only be 40 kohm or 4 kohm.

The TXS devices can have issues with heavy loading or with other pull-ups/pull-downs on the I/O lines. Since you have two in series you need to make sure whatever is driving the line low can sink the amount of current from the pull ups of both devices.

Logic

Logic forum

TXS0104E: TXS0108E Connect TXS0104E Problem