LSF0102-Q1: Internal fet ON

Jayjit Yadav

Part Number: LSF0102-Q1
Other Parts Discussed in Thread: TXS0102, LSF0108

Hello ,

we are thinking to use this part for levelshifter in I2C Communication but our one of the slave(RTC IC) having 3ma to 8ma Sink Current (IoL),but our controller supports to 1ma sink current as I seen in the video that the internal fet will directly on and when driving low from the controller, Current from all the pullup will go into the controller, at that time may be our controller damage due to its low sink current capacity could you have any other solution for the level shifter can we avoid internal fet turning on in any other devices(Levelshifter) from TI what about the TXS0102 ?

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 325520 points

The TXS has internal pull-up resistors (2× 10 kΩ in parallel), which should be suitable for your controller.

But the TXS's edge accelerators do not work well with large buses. If your I²C bus is large, consider using an I²C buffer instead.

0 Jayjit Yadav over 6 years ago in reply to Clemens Ladisch

Prodigy 180 points

actually our problem is pullup current from both(Master and slave) Pullup resistors goes into the Master(Controller) or slave(RTC) IC when driving output low as seen in video tutorial of LSF0108. Can we have any other solution for non isolated level shifter whose pull up current will be drive through only respective Master or Slave ??

0 Clemens Ladisch over 6 years ago in reply to Jayjit Yadav

Guru 325520 points

That's what I²C buffers are for.

0 Karan Kotadia over 6 years ago in reply to Clemens Ladisch

TI__Genius 16735 points

Hi,

You can filter through our parametric search tool to find the best I2C buffer that fits your need.

http://www.ti.com/interface/i2c/level-shifters-buffers-and-hubs/products.html#p2192=Buffer&!p2068=VCC%20Single%20Supply&sort=o1;asc

Thanks!

-Karan

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LSF0102-Q1: Internal fet ON