TMUX7412F: TMUX7412FRRPR Usage problem

Part Number: TMUX7412F
Other Parts Discussed in Thread: TMUX7412, TMUX6212, TMUX6202, , TMUX6201

Dear TI Engineer:

We have purchased some products from your company and encountered two issues during use, which are inconsistent with the manual description.

Question 1:

TMUX7412 IC,The circuit design using this chip did not match the description in the manual (as shown in Figure 1) during actual testing.

TMUX7412 test conditions:VDD=+5V,VSS=-5V,SEL1=3.3V,S1=+5V,D1 connected to 1K resistor to ground.

TMUX7412 test result:The D1 terminal can only measure a voltage of 3.9V; When VDD is increased to 6V and S1 is increased to+6V, a voltage of 4.9V is measured at the D1 end, which means that there is a voltage difference of about 1.1V between the output end and the VDD power supply voltage. However, the manual describes the voltage between VSS and VDD as: VSS~VDD.

图1 TMUX7412 recommended operating conditions

Comparative testing: TMUX6212 chip was also used in the product design, and the voltage range described in the chip manual for VS and VD is consistent, ranging from VSS to VDD.

TMUX6212 test conditions: VDD=+5V, VS=-5V, SEL1=3.3V, S1=+5V, D1 connected to 1K resistor to ground.

TMUX6212 test result: A voltage of 5V can be measured at the D1 end. When VDD is applied to+6V and S1 is applied to+6V, a voltage of 6V is measured at the D1 end. The chip is consistent with the description in the manual (as shown in Figure 2).

图2 TMUX7412 recommended operating conditions

I would like to know if the issue that occurred is due to the TMUX7412 chip manual not describing a pressure difference of around 1.1V, or is there an abnormality in the purchased product, or is there an issue with my testing method?

Question 2:

In actual testing of the TMUX6202 chip, the switch closed when SEL=1, which does not match the manual description. I would like to know if it is a problem with the purchased product or the manual description?

Best Regards

  • Hey yingjiao,

    I believe what you're seeing is the RON curves affecting the drop you're seeing. 
    On the TMUX7412F when you get closer to the rail (5V) your RON will increase quite a bit. For example, I'll show the 10V supply case below. It should closely math the +/-5V :

    While in the TMUX6212 is a lot more flat.

    Could you increase the supply and check the drop there? Typically for these devices it's best to give a little headroom on your supply vs the input voltage.

    For the TMUX6201, this is a fix that is currently in the works. You are correct though, the truth table and image are backwards.

    Thanks,
    Rami

  • This comment about the TMUX6201 and TMUX6202 is exactly what I am seeing on my design! The active level on SEL is inverted from the datasheet description!

  • Hi Terry.

    This datasheet error should be fixed within the next 1-2 weeks. Apologies for any issues this may have caused. 

    Regards,

    Alex