Isolation forum - Recent Threads

SN6505B: Ringing on positive and negative flank on both switchnodes

Ronny Ståhle — Wed, 01 Jul 2026 13:24:16 GMT

Part Number: SN6505B

Hi,

I'm evaluating SN6505B and I have added a load on the secondary side of appr 130mA. The driver SN6505B is patched onto my board but I have tried to keep the patch wires short and tight.

The output from the tranformer is fed to a 5V LDO and it is on the LDO output on which I have added the 130mA resistive load.

The circuit works (with a stable output voltage of appr 6.5V) but when looking at the two (D1 and D2) switch terminals I see symmetrical short ringing on both positive and negative flanks for both D1 and D2, please see the attached oscilloscope screenshots.

So, I wonder what the root cause is and how to get rid of this and/or minimize the ringing.
Is it caused by the patched in set up or do we need an RC snubber betwork on each switchnode, or do you need to change the capacative decoupling somehow ?

Best regards

Ronny

TPS2663: About reverse polarity protection

Po Yu Wang — Wed, 01 Jul 2026 09:51:44 GMT

Part Number: TPS2663

Hi TI Team,

I noticed in another thread that it is recommended to add a series resistor of $300\text{ k}\Omega$ or higher between IN_SYS and the UVLO/OVP pins to protect them from negative voltage transients.

Following this guidance, I performed some measurements on our board and obtained the following results:

When applying -24V to the input: The voltage at the UVLO pin is -0.557V, and the OVP pin is -0.355V.
When applying +24V to the input: The voltage at the UVLO pin is 1.42V, and the OVP pin is 0.967V.

The actual resistor values used in my circuit are $R_1 = 750\text{ k}\Omega$, $R_2 = 15\text{ k}\Omega$, and $R_3 = 32.4\text{ k}\Omega$.

The schematic configuration and the definitions of $R_1$, $R_2$, and $R_3$ are shown in the image below:

It appears that the internal protection (such as internal ESD clamping) is functional because the voltages are being clamped. However, even with the $>300\text{ k}\Omega$ current-limiting resistors in place, the measured negative voltages (-0.557V and -0.355V) still exceed the Absolute Maximum Rating of -0.3V specified in the datasheet.

Could you please help clarify the following?

Is this behavior expected when a large series resistor is used to limit the injection current?
Does violating the -0.3V absolute maximum rating under this current-limited condition pose any risk to the long-term reliability of the device?

XDS110ISO-EVM: Isolated Debugger requirement

Suhani Tandle — Thu, 25 Jun 2026 12:34:52 GMT

Part Number: XDS110ISO-EVM

Hi,
My application requires real-time debug of a microcontroller's GPIO pin connected to a rectified AC source. For this, I want to isolate the grounds of the MCU and the Rectifier, from my PC's ground.
Will using an isolated debugger solve this issue? If so, is XDS110ISO-EVM a good solution to use?
Or is using a USB isolation better?
Note that the AC source to the MCU is a scaled down input from grid, via a step down transformer.

Thank you
Suhani Tandle

RE: XDS110ISO-EVM: Isolated Debugger requirement

Suhani Tandle — Wed, 01 Jul 2026 09:14:13 GMT

Thank you, Peter, will do the same.

Regards,
Suhani Tandle

ISO7041-Q1: ISO7041-Q1: Part failure during prototype testing

Kalpak Gondane — Tue, 30 Jun 2026 09:38:37 GMT

Part Number: ISO7041-Q1

We are using ISO7041-Q1 digital isolator as a bridge between MCU (TMS320F28P65) and the UIR IC (BQ79718-Q1) in our BMS. However, we are observing the failure of the isolator IC in some cases during the initial phase of assembly and testing. We would like to understand the possible causes of failure.

RE: ISO7041-Q1: ISO7041-Q1: Part failure during prototype testing

Koteshwar Rao — Tue, 30 Jun 2026 21:34:38 GMT

Hi Kalpak,

Thanks for reaching out.
Could you please elaborate and provide details on the issue to be able to help you better?
Describe if this is a communication issue or device getting damaged. Describe the test conditions under which this happened and specifics on what test was being conducted. Share ISO7041 input/output waveform so that we can confirm what part of the isolator is not functioning. Share schematic and PCB layout.

Provide as much detail as possible to help you with the issue, thanks.

Regards,
Koteshwar Rao

ISO1211: Requested the non-encrypted LT spice simulation model

Vignesh M1 — Fri, 26 Jun 2026 04:20:06 GMT

Part Number: ISO1211

Hi,

I'm requested to provide the non-encrypted LT simulation spice model.

Now I have downloaded the spice model has encrypted.

Regards,

vignesh

RE: ISO1211: Requested the non-encrypted LT spice simulation model

Varun Kumar — Tue, 30 Jun 2026 14:47:25 GMT

Hi Vignesh,

Well, I'm not sure about the differences between the ISO1211 and the other ICs that you've mentioned above, but please understand that -> TI's preferred simulators are TINA-TI and PSpice® for TI, which natively support all TI model formats, including encrypted ones.

Hence, we recommend using PSpice® for TI which is free and natively support all TI SPICE models including encrypted ones, avoiding these issues altogether.

Also, until and unless you have NDA signed with TI, unencrypted models cannot be shared even if it's available internally.

And if it's not available, which I'm yet to get a confirmation on, then we cannot support this request.

Regards
Varun

ISO1211: Isolation connection for FGND and GND

Pavan Patil — Mon, 29 Jun 2026 07:53:38 GMT

Part Number: ISO1211

Hello TI,

We are using ISO1211 for reading our digital inputs.
Can ISO1211 function the same when both the grounds FGND and GND are connected to same ground?
Does using this IC with same ground, effects in EMI/EMC?

Currently in our system we don't need isolation, can you suggest if any other IC having similar function without isolation is available.

Thank you,
Pavan Patil

RE: ISO1211: Isolation connection for FGND and GND

Varun Kumar — Tue, 30 Jun 2026 14:44:26 GMT

Hi Pavan,

No, it does not.

If anything, it should only get better as the EFT and Surge stress can now bypass through the larger PCB area rather than stressing the internal isolation barrier alone.

Regards
Varun

RE: XDS110ISO-EVM: Isolated Debugger requirement

Peter Luong — Tue, 30 Jun 2026 12:15:44 GMT

Hi Suhani,

You can refer to the EVM user guide for this XDS110ISO-EVM, it supports JTAG, cJTAG, and SWD. The firmware of the MSP432 can remain the same and you can test the connection with the target configuration file

Regards,

Peter

ISO3086: Regarding 4M Changes of the Device

Kyohei — Mon, 15 Jun 2026 07:40:33 GMT

Part Number: ISO3086

Hi team,

Our customer is using this device in a mass-production model, and we have confirmed the 4M change based on the PCN notification issued in 2023.

With this 4M change, we observed a reduction of approximately 5 mA in current consumption when comparing device 1 to device 2. However, for IC 3, which is from the same lot as 2, we have observed a phenomenon where the current consumption is approximately 15 mA lower than that of 2.

Questions:

Although ICs 2 and 3 have different markings, can you confirm whether they are indeed from the same lot?
We are currently confirming the reel label information with the customer.
Is it possible to estimate the cause of the difference in current consumption based on package differences between 2 and 3?

Pre-PCN device

2. Post-PCN device (approx. 5 mA lower current consumption than (1))

3. Post-PCN device (approx. 15 mA lower current consumption than (2))

Best regards,

Kyohei

RE: ISO3086: Regarding 4M Changes of the Device

Varun Kumar — Tue, 30 Jun 2026 07:55:12 GMT

Hi Kyohei,

Yes, I am trying to get the variation internally from our teams and will reach out to you over email.

I would like to re-state that I totally understand that customer is surprised by a reduction in device current but a reduction in supply current values DOES NOT imply a Quality Issue until and unless there's an issue affecting device functionality or any other datasheet parameters values.

Regards
Varun

ISO1042: QC flow of ISO1042DWVR

Shigeki Suzuki — Fri, 19 Jun 2026 03:11:17 GMT

Part Number: ISO1042

Please send the QC flow of ISO1042DWVR

RE: ISO1042: QC flow of ISO1042DWVR

Shigeki Suzuki — Tue, 30 Jun 2026 05:11:47 GMT

Rao san

Thank you for the reply.

I would like to have the QC process chart.

But I seem to send my inquiry to wrong channel.

So I will resend proper channel.

Please close this request.

RE: ISOW3080: Check compatibility with NOVOSENSE NSIP93086-DSWR

Varun Kumar — Tue, 30 Jun 2026 05:03:45 GMT

Hi Pietro,

Thanks for reaching out and your interest in evaluating ISOW3080.

Absolutely, ISOW3080 is a P2P replacement for NSIP93086 - if the speed is limited to 38400bps.

Below is a snapshot for comparison:

ISOW3080 Pinout -

NSIP93086 Pinout -

Regards
Varun

ISOW3080: Check compatibility with NOVOSENSE NSIP93086-DSWR

Pietro Piol — Mon, 29 Jun 2026 15:59:39 GMT

Part Number: ISOW3080

I need to verify if ISOW3080DWE is P2P direct replacement with NOVOSENSE NSIP93086-DSWR.

Speed is not a problem: in my application we are using 38400bps

If No, please let me know the direct TI replacement.

Thanks in advance

Pietro

RE: ISO1211: Requested the non-encrypted LT spice simulation model

Vignesh M1 — Tue, 30 Jun 2026 04:21:33 GMT

Hi,

Thanks for your support. Actually the TI fewer ICs Spice models were supported in LT spice. The IC (ISO1211) also having the spice model but it won't work in the LT spice.

RE: ISO1211: Isolation connection for FGND and GND

Pavan Patil — Tue, 30 Jun 2026 04:13:15 GMT

Hello Varun,

Thank you for the reply.

Just wanted to clarify that making two grounds same doesn't effect in EMI/EMC (EFT and Surge).

Thank you.

RE: ISOW6442: Differences between ISOW774x and ISOW642x

Varun Kumar — Mon, 29 Jun 2026 17:34:22 GMT

Hi Ryusuke,

From VISO and VIOTM point of view -> ISOW644x and ISO774x is exactly same.

Only for VIOWM, the ISOW774x is rated higher than ISOW644x for which I had provided my comment earlier - apologies if this has created confusion.

Regards
Varun

ISOW6442: Differences between ISOW774x and ISOW642x

R.Fukunaga — Thu, 25 Jun 2026 06:35:40 GMT

Part Number: ISOW6442

Hi all,

I am interested in the release of ISOW642x. I would like to understand the differences between ISOW774x and ISOW642x.
I understand that ISOW642x is released as a lower cost version of ISOW774x.
However, when I check the comparison chart, ISOW642x seems to be superior in all performance.

I understand that ISOW774x is High Voltage Ver.
I understand that this Hgih Voltage has higher VIOTM and VISO.
Is this understanding correct?
I would appreciate it if you could tell me what the difference is.

Best Regards,

Ryusuke

ISO6742: Solder reflow profile inquiry

Abhishek Manoj — Mon, 29 Jun 2026 10:09:58 GMT

Part Number: ISO6742

Hi Team,

Please provide the lead free solder reflow profile graph and details for the part ISO6742QDWRQ1.

Regards,

Abhishek

RE: ISO6742: Solder reflow profile inquiry

Ethan White — Mon, 29 Jun 2026 14:27:16 GMT

Please refer to this app note:

https://www.ti.com/lit/an/spraby1a/spraby1a.pdf?ts=1782743031588&ref_url=https%253A%252F%252Fwww.google.com%252F

Keep in mind these are MSL2 devices.

RE: ISOUSB211-Q1: Design Review

Varun Kumar — Mon, 29 Jun 2026 13:34:42 GMT

Hi Krishna,

Yes, this is good to go.

Just make sure to have the J1, J2, J11 and J12 shorted all the time during device's operation.

Regards
Varun

ISOUSB211-Q1: Design Review

Sri Krishna V — Tue, 16 Jun 2026 16:40:10 GMT

Part Number: ISOUSB211-Q1

I am using ISOUSB211 not ISOUSB211-Q1 as it is not yet avaliable for purchse.

Can you help us review the schematic ISO USB.pdf