Isolation forum - Recent Threads

ISOUSB211: Failure of the ISOUSB211DPR EMC test

Andrzej Kuczwara — Mon, 03 Aug 2026 07:37:10 GMT

Part Number: ISOUSB211

Hello.

I am designing a circuit using the ISOUSB211DPR.
During engineering tests at a certified laboratory, it turned out that we have EMC exceedances as shown in the image below. Due to company policy, I cannot post the PCB layout here.
I have now ordered an evaluation board to test it in the lab and modify my design.

EQ0 and EQ1 are set to LOW on both sides.

The PCB is 1 mm thick, 4 layers; the USB trace width resulting from the stackup is 8.6 mil, with a gap of 6 mil.

The USB line lengths are balanced: 2085 mil on the primary side and 930 mil on the secondary side. I used common-mode and ESD filters on both sides: ECMF02-2AMX6

VBUS: 5V from the USB host,
V1P8V1: External LDO,
VBUS2: 3.3V from an external 3V3 LDO ,
V2P8V2: Internal ISOUSB LDO,
CDPENZ1 / CDPENZ2: High (3V3 connected to V3P3V1 / V3P3V2),
PIN 14/15: floating.

Would it be possible to contact support via email?

ISO1640: Ask ISO1640 VCC1 max current consumption while VCC2 power / signal removed

Roy Chan — Mon, 03 Aug 2026 07:00:18 GMT

Part Number: ISO1640

Hello Expert:

We have an urgent case need to estimate the max current consumption of ISO1640 product as below . can you please help provide the max current consumption of VCC1?
Condition: Revmove VCC2 / SDA2/SCL2 all power and signal side , what's the max current consumptoin on VCC1 ?( ICC1 max) = ?mA

ISOUSB211: Schematic Review

Francis Jiang — Mon, 03 Aug 2026 06:09:10 GMT

Part Number: ISOUSB211

Hi Team,

Could you please help review below schematic? Thanks. Besides the lack of VBUS TVS, any other issues?

BRs,

Francis

ISOW3080: VISOOUT Selection and bus voltage ABS MAX

Hideki Hayashi1 — Wed, 29 Jul 2026 15:40:14 GMT

Part Number: ISOW3080
Other Parts Discussed in Thread: PROFIBUS, , THVD2450

Hi team,

I have two questions.

There are two option depending VISOOUT (5V or 3.3V). Customer want half-duplex RS485 Transceiver (no PROFINET), are both able to be used? Which should be better?
Do you specify the maximum rating for differential bus voltage (VA - VB) and (VY-VZ)? I only see Vx-GND2 as below

Best regards,

Hayashi

ISO6742: Request for Product Lifecycle Confirmation

vaishnavi poojary — Wed, 29 Jul 2026 11:39:45 GMT

Part Number: ISO6742
Other Parts Discussed in Thread: ISO6442-Q1

Greetings from iWave Systems Technologies Pvt. Ltd.

We are evaluating the below Texas Instruments component for use in one of our medical products.

ISO6742QDWRQ1

Could you please confirm whether this component is currently active and expected to remain available for supply over the next two years?

Additionally, kindly let us know whether there are any planned End-of-Life (EOL) notifications, Product Change Notifications (PCNs), or any other lifecycle changes associated with this part.

If this component is expected to become obsolete or discontinued, kindly recommend a suitable replacement part with equivalent electrical and mechanical specifications.

Thank you for your support. We look forward to your response.

UCC12040: Weight for MPN UCC12040DVE

Rashi Gupta — Wed, 29 Jul 2026 08:10:51 GMT

Part Number: UCC12040

Hi, We are using below MPN in our program.

Kindly provide the weight for the part on priority.

UCC12040DVE

ISO1432: bsolescence report for the components

Hardware Intern — Wed, 29 Jul 2026 06:52:03 GMT

Part Number: ISO1432

Could you please provide an obsolescence report for the components listed below? We are seeking long-term availability for a minimum of 10 years. For our internal tracking, we categorize obsolescence into the following four groups:

- Category A: EOL > 10 years
- Category B: EOL > 5 years
- Category C: NFRD / Obsolete
- Category D: EOL not confirmed by manufacturer

If you could help us identify the EOL status and the corresponding category for the following components, it would be much appreciated.
Also pleaseprovide information of MSL level, ESD, storage temperature, grade, ROHS, Lead finish

Part Number:

TPSM828502WRDYRQ1

TPS74601PQWDRVRQ1

SN65LBC179QDR

UCC12051QDVERQ1

ISO7742FQDWRQ1

TPS71701QDRVRQ1

ISO1432BDW

LM4040QCEM3-3.0/NOPB

TMP235AEDBZRQ1

ISO6763: Transistor and Gate Count

Colin Wiese — Tue, 28 Jul 2026 13:59:14 GMT

Part Number: ISO6763

Hello,

I am contacting you to ask about the transistor and gate count on ISO6763FQDWRQ1. We need this for the SR-332 standard, so an approximate count will work for us.

Thanks

ISOW1044: Power Supply decoupling

Andreas Nestler — Mon, 27 Jul 2026 07:48:52 GMT

Part Number: ISOW1044
Other Parts Discussed in Thread: LM317

Hello,

we are using 4x ISOW1044 in our design. We are facing noise issues on our +5V supply (80 to 100mVpp). Since the +5V supply rail is also used for other noise sensitive application we would like to minimize the noise. The ISOW application circuitry follows the recommendatations according datasheet so we have the ferrit beads and the capacitance on VDD pin:

Our +5V regulator is a buck converter with total 4x10uF output capacitance and a small ferrit bead at the output. I guess that the noise we observe are not from our 5V converter since the ripple signature is more or less random.

Q1: what are the recommendations for the driving supply? Do we have to add bulk capacitance and how much?

Q2: What is the frequency of chip internal isolated DCDC converter? Datasheet states in Feature section::

To be honest 25MHz seems to be a quiet high switching frequency.

Q3: Can you confirm the 25MHz switching frequency of internal DCDC converter?

Thanks in advance!

Best regards, Andreas

TL2845B: High voltage genration

Pritam Malusare — Sat, 25 Jul 2026 16:18:16 GMT

Part Number: TL2845B
Other Parts Discussed in Thread: TL2845

Hi everyone,

I'm designing high voltage genration circuit for 50V to 5000V dc using TL2845. but I'm not able to archive voltage below 1300V. I've tried changing feedback resistor ladder path, COMP-Vfb pin resistors but not working. could anyone help with this.

ISOM8111: DIN EN 13849-2

Hanno Reimer — Fri, 24 Jul 2026 17:38:30 GMT

Part Number: ISOM8111

I have the following question about the Texas Instruments ISOM8111 opto-emulator:

In DIN EN 13849-2 Table D.19, a fault exclusion for optocouplers is for a short circuit between input and output, If the optocoupler is built according to IEC 60664-1 overvoltage category III.

1. Is the opto-emulator ISOM8111 built according to overvoltage category III?
2. Does this error exclusion also apply to ISOM8111?
3. Is there a confirmation / certificate for this?

ISOW1432: Schematic Review

João Antunes — Fri, 24 Jul 2026 15:44:25 GMT

Part Number: ISOW1432

Can you review this schematic an give me some feedback?

Plesae advise if the connections on the A/B/X/Y pins are correct.

I saw this in the forum and no one poited out tht those connections were wrong:

https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1627494/isow1412-review-schematic

Best

Luis

ISO7760: FSI through Isolator signal integrity

Sebastian Glas — Thu, 23 Jul 2026 16:22:20 GMT

Part Number: ISO7760
Other Parts Discussed in Thread: ISO7763, ISO6463, SN74LVC1G34

Hi,

I'm designing an FSI network where a host broadcasts to three F28P65x nodes through an ISO7763 reinforced digital isolator. On the isolator's secondary side, the three forward FSI signals (TXCLK + TXD0 + TXD1) are routed as a single single-ended multidrop bus that reaches the three DSPs in sequence:

- ISO7763 output -> Node A: 70 mm
- Node A -> Node B: +52 mm (122 mm from the isolator)
- Node B -> Node C: +48 mm (170 mm from the isolator)

The far end (Node C) is unterminated.

FSI configuration: 200 Mbps using 2 data lines (TXD0/TXD1) with a 50 MHz forwarded clock.

Board constraint: the stackup is NOT impedance-controlled (cost), traces are ~5 mil on an inner layer, so Z0 is roughly 55-60 ohm nominal but uncontrolled.

Observed issue: we are seeing signal-integrity problems, and the counterintuitive part is that the node closest to the isolator (Node A) fails while Nodes B and C work reliably. This seems consistent with reflected-wave switching on the unterminated bus: with the isolator's CMOS output impedance the incident step lands near the receiver threshold, and the near node dwells there longest (until the reflection returns from the open far end), while the far node sees the incident and reflected edges combine into a clean full-amplitude transition.

I'd appreciate guidance on the following:

For a single-ended FSI multidrop driven from an isolator output, what buffer or transceiver would you recommend to drive the bus reliably at 50MHz?

Thanks in advance for any recommendations.

TPS25981: Schematic Verification of TPS259813ARPWR

Irfan Shaikh — Thu, 23 Jul 2026 04:40:25 GMT

Part Number: TPS25981

Hi Team,

I have used TPS259813ARPWR for eFuse in my design, where input is 12V, 8A and i have attached the schematics for verification.
Kindly verify it let me know if any changes is required to be done?

DESIGN8.pdf

Regards,
Irfan

ISOUSB111: ISOUSB111: Zero inventory - Safe for new designs?

Abdurrahman Zaim — Wed, 22 Jul 2026 09:13:06 GMT

Part Number: ISOUSB111

Hi ,

I am currently evaluating the ISOUSB111 for use in an upcoming new project.

However, I have been monitoring the inventory on the TI website for the past month, and the stock has consistently remained at zero with no updates. Because of this, I have a few concerns before we commit to this part for our design:

Are there any plans for the ISOUSB111 to become obsolete, or will it soon be marked as Not Recommended for New Designs (NRND)?

Given the current stock situation, is it safe and recommended to design this component into a new project right now?

If the part is still fully active, what are the current lead times? What is the recommended procedure for ordering this part while the web inventory shows 0?

Thank you in advance for your help!

ISO1212: ISO1212 || Layout guidelines

Jyoti Vaishnav — Tue, 21 Jul 2026 12:22:14 GMT

Part Number: ISO1212

Hi TI Support,
We are using the ISO1212DBQR in our design with the bridge input configuration, similar to the reference circuit shown below (BAT54SW bridge network on both input channels).
Our question is regarding the PCB layout recommendation for the FGND pins (FGND1/FGND2).
In our implementation, the field inputs are connected through the bridge rectifier network, and the FGND nets are not directly tied to the system GND.
Could you please clarify the following:

Is it recommended to create dedicated copper polygons for FGND1 and FGND2 around the ISO1212 on the PCB, even when using the bridge input configuration?
Should the FGND polygons remain electrically isolated (floating) except for their intended field-side connections, or is it acceptable to route them as traces only?
Are there any specific layout recommendations for the bridge input configuration to achieve the best EMC/ESD performance?

ISO1212: ISO1212 || Layout Guidelines

Jyoti Vaishnav — Tue, 21 Jul 2026 12:13:58 GMT

Part Number: ISO1212

Could you please clarify the following:

Is it recommended to create dedicated copper polygons for FGND1 and FGND2 around the ISO1212 on the PCB, even when using the bridge input configuration?
Should the FGND polygons remain electrically isolated (floating) except for their intended field-side connections, or is it acceptable to route them as traces only?
Are there any specific layout recommendations for the bridge input configuration to achieve the best EMC/ESD performance?

ISOW6442: I2C isolation Circuit around ISOW6442

Mohan Nagella — Mon, 20 Jul 2026 12:30:04 GMT

Part Number: ISOW6442
Other Parts Discussed in Thread: ISOW7742, ISO1640

Hello TI Team,

I see a application note where the circuit built using ISOW7742 could be used for I2C communication. www.ti.com/.../slyt403a.pdf

My question is can I use this circuit for bidirectional SCL and SDA lines of SMBUS using ISOW6442V IC which would be soon released into market. My intention to use this chip is that I can power using +5V and VDDL at +3.3V which eliminates the use of level translation at mcu side.

With Regards

Mohan

ISOW6441: UL and VDE Certificates Check

Yuxi Liu(Tony) — Mon, 20 Jul 2026 09:26:58 GMT

Part Number: ISOW6441

Hi TIer

Do we have UL and VDE Certificates of ISOW6441 now?

If not , Do we have time plan?

Thank you very much.

ISOUSB211: ISOUSB211: Can side 2 be powered from side 1 if VBUS not needed for Side 2?

Jonathan Lui — Fri, 17 Jul 2026 22:11:47 GMT

Part Number: ISOUSB211

Hi,

I am designing an unique application with the ISOUSB211 where:

Side 1 is the host side, VBUS1 (5V) from the host is available to power the ISOUSB211.
Side 2 is the device side, and we don't need to provide VBUS to the device.
We are just trying to isolate the USB data lines.

For the ISOUSB211 power pins, there are side 1 power pins (VBUS1, VCC1, etc) and side 2 power pins (VBUS2, VCC2, etc).

Since we aren't passing VBUS to side 2's device, I am not planning to add a transformer for VBUS to save space. My question is if side 2 power pins can be powered by VBUS1 (same source as the side 1 power pins)? I think this is fine, but would like to confirm that there aren't any shortcomings that I am not aware of.

Thanks,
Jonathan

SN6507: SN6507 and transformer get to 60C even during idle state

Timur Starobinets — Fri, 17 Jul 2026 18:19:51 GMT

Part Number: SN6507

Hi,

I am working on a circuit with 24V to 24V isolation using SN6507 and Würth Elektronik 750319697 transformer. I am seeing both parts get very warm even under idle condition with minimal current draw. The parts are getting to about 60C.

I tried chaning Rilim in case I was hitting OCP hiccip mode for some reason (didn't help), changing slew rate resistor, removing 10uF cap on the output to see if I notice any change but I didn't see any significant changes in temperature. The rectifying diodes I originally used are onsemi ES1C and I tried switching to a Nexperia PNE20020EPX diodes but again, I do not see any improvement.

Can you suggest what could be behind this? I've seen a couple of other support requests for the similar issue but I haven't seen any updated resolutions to them. Thanks.

LM5156: LM5156 Secondary-Side Regulated Isolated Flyback in PSpice for TI

Robin Cromm — Fri, 17 Jul 2026 13:56:14 GMT

Part Number: LM5156

Hello, I'm simulating a secondary-side regulated isolated flyback circuit with an LM5156 in PSpice for TI. Unfortunately, different ground symbols in this program are still connected to each other and aren't truly isolated. How can I solve this problem, or have I perhaps overlooked a setting? Best regards and thanks in advance.

LMG3522R030-Q1: Can we use the single isolator to drive two LMG3522R030-Q1 parallely

harish kv — Thu, 16 Jul 2026 05:25:55 GMT

Part Number: LMG3522R030-Q1

Hi Team,

We wanted to understand whether it is recommended to use a single isolated gate driver to drive multiple GaN MOSFETs connected in parallel.

We have attached a reference schematic for your review, where a single isolated gate driver is used to drive two parallel GaN devices.

Could you please clarify the following:

Is it recommended to use a single isolated gate driver for parallel-connected GaN MOSFETs?
If yes, what are the design considerations to ensure proper current sharing and reliable switching?
Are there any recommendations regarding:
- Individual gate resistors
- PCB layout and gate loop matching
- Gate driver current capability
- Device matching or any other precautions

We have attached the reference schematic for your convenience.
GaN HI STAGE.pdf

ISO6742-Q1: Output Pin State When One Side Loses Power Supply (VCC1 or VCC2)

Chuqiang Wen — Wed, 15 Jul 2026 14:28:11 GMT

Part Number: ISO6742-Q1

Hi team,

I am working with the ISO6742F-Q1 digital isolator and have a question regarding the output behavior when one side loses its power supply.

Application Setup:

Side 1 (primary) is powered by a 5V supply (VCC1)
Side 2 (secondary) is powered by a separate 5V supply (VCC2)
Both sides share a common ground (GND1 = GND2)

My Questions:

If VCC1 (primary side) is lost while VCC2 remains powered, what is the output state of the Side 2 output pins? Do they go High, Low, or High-Z?
If VCC2 (secondary side) is lost while VCC1 remains powered, what is the output state of the Side 1 output pins? Do they go High, Low, or High-Z?
Does the ISO6742F-Q1 have a Failsafe feature that defines a default output state when the transmitting side loses power? If so, what is the default failsafe output level?

Any application-level guidance would be greatly appreciated!

Thanks!

Ethan Wen

ISOW1432: ISOW1432 General purpose logic pin configuration

?? ?? — Wed, 15 Jul 2026 08:15:22 GMT

Part Number: ISOW1432

Dear TI.

I have a question about ISOW1432.

I don't use General purpose logic pin which is IN(14pin) and OUT(7pin).

I'm considering below.

IN(14pin):Connect to GND2
OUT(7pin):Unconnect(Open)

Please let me know if this approach is acceptable.
Best regards.