Amplifiers forum - Recent Threads

AMC1311-Q1: 20V negative offset during switching on HV bus

ALI Benzehra — Wed, 28 Oct 2026 22:54:49 GMT

Part Number: AMC1311-Q1
Other Parts Discussed in Thread: AMC1311, OPA376

Subject: Technical Support Request — AMC1311 Measurement Offset and Common-Mode Noise

Hello,

We are using the AMC1311 to measure the voltage of an HVDC bus. In our current PCB layout, a ground plane is present beneath the AMC1311 package, which does not appear to comply with the layout recommendations in TI’s design documentation. We would like to understand whether this could be contributing to the measurement issues we are seeing.

The AMC1311 differential outputs are connected to a differential signal-conditioning circuit built around an OPA376. When the HVDC bus is at approximately 400 V, our system reports a voltage of about 380 V, corresponding to an error of approximately −20 V. We also observe significant common-mode noise in the measurement.

Could you please advise on the following points?

Could the ground plane beneath the AMC1311 package affect its isolation performance or measurement accuracy, and could it contribute to the observed offset or noise?
What would be the recommended checks to identify the source of the approximately 20 V measurement error? We are particularly interested in possible effects from the AMC1311 input network, output filtering, OPA376 circuit, PCB layout, and measurement setup.
Would adding a capacitor directly between the OPA376’s IN+ and IN− inputs help reduce the observed noise? If so, are there any recommended design considerations for selecting the capacitor value, such as bandwidth, stability, or settling time?
Are there specific layout or filtering recommendations for the AMC1311 and the OPA376 stage that we should review?

Thank you for your support

INA105: customer quality issue currently impacting production and customer deliveries

veronica romero — Wed, 28 Oct 2026 18:09:57 GMT

Part Number: INA105

Urgently need your help with INA105KU/2K5 (Creation IPN 0711800), which has been linked to a significant customer quality issue currently impacting production and customer deliveries.

Instrument lab has completed their investigation and confirmed a correlation between the manufacturing location of the components:

Parts marked CSO:RFB are associated with failures in the field and during testing.
Parts manufactured at CSO:SHE have been tested and are performing as expected.
Based on current demand, this issue currently represents approximately $441K of revenue risk across October and November.

The customer's investigation identified failures on analog board assemblies where multiple INA105 devices were drawing excessive current during startup, resulting in board failures. Through traceability reviews and testing, the issue appears to correlate to material sourced from the RFB manufacturing location, while material from SHE has not exhibited the same behavior. During our review of the device specifications, we also identified a notable difference in the ISC (Short Circuit Current) parameters between the two manufacturing locations:

Sinking Current (CSO:SHE): 10 mA
Sinking Current (CSO:RFB): 70 mA

This significant difference appears consistent with the customer's findings of excessive current draw during startup and raises concerns regarding parametric differences between devices produced at the two manufacturing locations. As part of our containment actions, we have quarantined identified RFB-marked inventory and are working closely with the customer to prevent further impact. However, we require immediate support from Texas Instruments to understand why material from different manufacturing locations appears to be performing differently in the application. In addition to the quality concern, we currently have open orders totaling approximately 17,500 pieces scheduled for delivery between November 2026 and February 2027, as well as an additional customer-managed order for 2,494 pieces.

Open Supply Exposure

5,000 pcs due November 2026
2,494 pcs due November 2026
5,000 pcs due December 2026
5,000 pcs due February 2027

Total Open Supply Exposure: 17,494 pcs

Given the situation, we require immediate visibility into whether any future shipments are sourced from the affected manufacturing location.

Could you please urgently provide an update on the following, we will discuss this on the call.

Confirmation of the manufacturing site for all open and future shipments of INA105KU/2K5.
Identification of any open orders, lots, date codes, or shipments produced at the RFB manufacturing location.
Are there any known quality concerns associated with INA105KU/2K5 produced at RFB?
Can TI explain the reason for the ISC parameter differences between SHE and RFB manufacturing locations, specifically the sinking current specification of 10 mA vs. 70 mA?
Have there been any process, wafer fab, assembly, test, material, or supplier changes between the RFB and SHE manufacturing sites?
Was this device fully qualified across both manufacturing locations, and are these parametric differences expected and controlled?
Can TI provide lot traceability and identify any potentially affected date codes?
Is TI currently conducting an internal investigation and, if so, what are the preliminary findings?
What immediate containment actions does TI recommend?
Can TI provide replacement material from SHE or another unaffected manufacturing location to support production continuity?
What is TI's corrective action and recovery plan?

Given the customer impact, revenue exposure, and risk to upcoming shipments, we request an urgent response today and would appreciate scheduling a call with the appropriate TI Quality, Manufacturing, Operations, and Account Management teams as soon as possible.

INA226: Faulty bus, voltage and current reading

Deepansh Porwal — Wed, 28 Oct 2026 17:02:57 GMT

Part Number: INA226

Hello TI,
I am using INA226 for 36V monitoring at max 3A, I have set default configuration for configuration register and for calibration register I have 5mohm shunt resistor. My supply is at 36V and after my I2C read I have 220A as hex value which corresponds to ~10V, after applying load, both shunt and current voltage is near to 0 only but supply current is around 150mA.
How can I read correct values?

INA193A-EP: MSL Level

Gary SMITH — Wed, 28 Oct 2026 15:18:21 GMT

Part Number: INA193A-EP

We have parts that the reel has MSL 1 but Data Sheet show MSL 2. What is correct MSL level

AM2612: Bug Report: Incorrect EQEP Position Counter Reset Mode Mapping in AM26x Embedded Coder Support Package 26.0.0

MINZHE GUAN — Wed, 28 Oct 2026 14:01:17 GMT

Part Number: AM2612
Other Parts Discussed in Thread: SYSCONFIG

Dear TI Support Team,

I would like to report a possible bug in the eQEP block implementation of the Embedded Coder Hardware Support Package for TI AM26x Microcontrollers.

Environment

  - Target board: AM261x LaunchPad
  - MATLAB/Simulink: R2026a
  - AM26x Embedded Coder Support Package: 26.0.0
  - MCU+ SDK for AM261x: 26.00.00.06
  - Peripheral: EQEP1
  - EQEP1 base address: 0x50271000

Problem description

In the Simulink eQEP block, I configured the position counter reset mode as:

  "Reset position counter on maximum position"

However, after generating and running the code, the EQEP position counter did not operate as expected. Inspection with CCS showed:

  QPOSCNT = 0x00000000
  QPOSMAX = 0x0000FFFF
  QEPCTL  = 0x00000008

The PCRM field in QEPCTL remains 00, meaning that the position counter is configured to reset on an index event rather than on the maximum position value.

For "reset on maximum position," I believe QEPCTL should contain the PCRM value 01, resulting in a value similar to:

  QEPCTL = 0x00001008

Generated code

The generated model code assigns:

  eqep_setup_struct.posCntrMode = 1U;

The support-package wrapper in MW_EQEP.c passes this value directly to the MCU+ SDK:

  EQEP_setPositionCounterConfig(
      ptr->base,
      ptr->posCntrMode,
      ptr->maxPosition);

However, the MCU+ SDK defines the reset modes as bit-field values:

  #define EQEP_POSITION_RESET_IDX           (0x0000U)
  #define EQEP_POSITION_RESET_MAX_POS       (0x1000U)
  #define EQEP_POSITION_RESET_1ST_IDX       (0x2000U)
  #define EQEP_POSITION_RESET_UNIT_TIME_OUT (0x3000U)

Therefore, passing 1U directly does not select EQEP_POSITION_RESET_MAX_POS. Instead, it affects a low-order control bit. After the watchdog configuration is applied, the final reset mode remains EQEP_POSITION_RESET_IDX.

Possible root cause

The Simulink mask appears to use ordinal values 0, 1, 2, and 3, while the MCU+ SDK function expects the encoded register values 0x0000, 0x1000, 0x2000, and 0x3000.

A mapping step may be required in the support-package wrapper, for example:

  uint32_t positionResetMode;

  switch (ptr->posCntrMode)
  {
      case 0U:
          positionResetMode = EQEP_POSITION_RESET_IDX;
          break;

      case 1U:
          positionResetMode = EQEP_POSITION_RESET_MAX_POS;
          break;

      case 2U:
          positionResetMode = EQEP_POSITION_RESET_1ST_IDX;
          break;

      case 3U:
          positionResetMode = EQEP_POSITION_RESET_UNIT_TIME_OUT;
          break;

      default:
          positionResetMode = EQEP_POSITION_RESET_IDX;
          break;
  }

  EQEP_setPositionCounterConfig(
      ptr->base,
      positionResetMode,
      ptr->maxPosition);

The default "reset on index" option does not expose the issue because its Simulink ordinal and SDK value are both zero. The issue appears when any non-default reset mode is selected.

Could you please confirm whether this is a known issue and provide an official fix or recommended workaround? It may also affect the "first index" and "unit timeout" reset modes.


Best regards,
Minzhe

OPA375: help recommend suit IC

Haiwen Huang — Wed, 28 Oct 2026 07:26:47 GMT

Part Number: OPA375
Other Parts Discussed in Thread: LMP7731, OPA328

Dears:

Customer need a part can support below requirment , Could you please help recommend a suit part ? Thanks.

1- BW at least 30MHz

2-Iq less than 1mA

3-need min work voltage less than 1.8V.

4-Vos less than 1mV.

TLV9004: TLV9004 1.8V operation

Ludwin Anton — Wed, 28 Oct 2026 07:01:18 GMT

Part Number: TLV9004
Other Parts Discussed in Thread: AM2434, TLV9054, TLV9064

Hello,

we intend to use the TLV9004 (or TLV9054, TLV9064) as a volatge follower to drive the ADC of the AM2434.

We plan to power the OPAMP with the 1.8V supply of the AM2434 which has a voltage tolerance of 1.8V +/-1.5%. This also ensures that the voltage specifications of the ADC inputs are not exceeded.

The TLV90x4 is specified from 1.8V to 5.5V, but not from 1.8V-1.5%.

Are there likely to be any problems if we operate the TLV90x4 at 1.8V ±1.5%?

LM2903B-Q1: LM2903BQDGKRQ1 mass production

Yuya Sato — Wed, 28 Oct 2026 05:16:24 GMT

Part Number: LM2903B-Q1

Hi,team

Our customer has asked us about the mass production start date of the LM2903BQDGKRQ1.

We understand that the device entered mass production in 2021. Could you please confirm the exact month when mass production started?

Your support would be greatly appreciated.

Best regards,

PSPICE-FOR-TI: Unable to Download TI for PSPICE

Priya Ramaswamy — Tue, 27 Oct 2026 19:00:38 GMT

Part Number: PSPICE-FOR-TI

I keep getting this error message everytime I click the TIsetup in downloads

OPA357: Hi-Side Rail to Rail drop-out at low currents

Daniel Egolf — Tue, 27 Oct 2026 17:33:42 GMT

Part Number: OPA357

I'd like to know if there is data on the actual non-ideal rail to rail high output voltage for OPA 357 in the at 3-4V supply range. The output current is less than 100µA. The data sheet has a graph that shows an approximate 140mV drop out at Vsupply =3V. How accurate is that graph?

INA105: INA105KU (CSO: SHE & CSO: RFB)

Ben Rota — Tue, 27 Oct 2026 16:17:34 GMT

Part Number: INA105

INA105KU CSO: SHE & CSO: RFB are behaving differently in our application. All boards with RFB are failing and SHE is passing.

When were both introduced to the Market?

Can we purchase only the SHE configuration?

OPA828: Applicable licence for OPAx828 PSpice Rev. D model in third-party desktop simulators

dean kerr — Tue, 27 Oct 2026 11:03:36 GMT

Part Number: OPA828

Hello TI Support,

Please confirm the licence terms governing the OPAx828 PSpice Model Rev. D distributed from the OPA828 product page as SBOMAJ0D.ZIP.

The proposed use is private engineering evaluation and circuit development involving the TI OPA828 device, using the model in LTspice or ngspice on an Apple Silicon Mac. The model would remain in controlled local custody and would not be published or redistributed.

TI's online Terms of Use section 7 points software without accompanying licence terms to the Evaluation, Development and Demonstration Software License Agreement. That document contains TI-processing-device restrictions, and section 1(f) prints “ninety (90) thereafter” without a time unit. Please clarify which terms apply to this desktop-model workflow and how any applicable licence duration is determined.

Could you provide the authoritative model-specific terms or written clarification covering:
1. Whether use in these third-party simulators on a non-TI desktop processor is permitted.
2. Applicable licence duration and any renewal, termination or acceptance requirements.
3. Internal storage/copying and access by engineering automation or authorised engineering contractors.
4. Sharing simulation results with authorised engineering reviewers, separately from the model source.

Please identify the governing document/version and any conditions that must be satisfied before model use.

Thank you.

XTR-ERROR-CALC: XTR305 Current Output Mode Simulation Issue (Sinking behavior & transfer function mismatch)

Marina — Tue, 27 Oct 2026 09:58:26 GMT

Part Number: XTR-ERROR-CALC
Other Parts Discussed in Thread: AMC3311, XTR305, TLV9002

Hello TI E2E Support team,

I am currently designing and simulating a signal conditioning circuit for an industrial data acquisition system. The main objective is to measure a high-voltage input up to 100V from an industrial machine, isolate it using the AMC3311, condition/scale it via a TLV9002 op-amp stage, and finally convert it into a current loop using the XTR305.

However, I am running into trouble with the XTR305 current output simulation in PSpice.

Current Setup & Behavior:

Input Stage: The high-voltage input 0-100v is scaled and isolated by the AMC3311, then converted to a single-ended 0-5v signal (V_Output) by the TLV9002.
XTR305 Configuration:
- Configured in Current Output Mode with digital pins set to M1 = 0V, M2 = 5V, and OD_N = 5V.
- Rset = 2.5k and Ros = 12.5k connected to the SET pin with a 5v reference.
- A 250ohm load resistor (R11) connected between DRV and GND.
The Issue: Based on the transfer function for the current output mode, for an input of 0-5V, the theoretical calculation should range from -4mA to +20mA. However, during the transient simulation, the output current (A_Output) is behaving like a sinking circuit running from -4mA to -20mA (or hitting convergence/saturation issues when trying to modify the resistor network).

Could you please advise on what might be causing this inverted/negative behavior or if there are specific model constraints regarding the reference configuration and supply rails for current output mode in simulation?

I have attached my current schematic and simulation files below. Any guidance would be greatly appreciated!

Project1.zip Project schematic.pdf

OPA388: Output swing for unity gain

Waldemar Heinrich — Tue, 27 Oct 2026 09:43:43 GMT

Part Number: OPA388

I configured my op amp as following to buffer reference for ADC. the input is free from oscillation. the output shows a voltage oscilation of 154kHz with 30mVpp. Could you explain why?

In the datasheet for OPA388 unity gain amp is declared as stable.

did I miss something?

kind regards

AMC0381D: Layout Recommendation

Kazuki Itoh — Tue, 27 Oct 2026 08:33:50 GMT

Part Number: AMC0381D

Hi team,

Could you please provide information regarding the recommended layout for the AMC0381D? Why is the distance from the SNSP pin guard ring to the low-side NC pin not meeting the clearance requirements? What exactly is a "keep-out zone"? In the EVM PCB layout, the GND2 copper appears not to take the keep-out zone into account.

As the datasheet doesn't provide enough information to interpret, I'd appreciate more specific explanation.

Best regards,
Kazuki Itoh

OPA4170: Query Regarding OPA4170AIPWR Input Voltage Behavior

Dineshkumar Jebastin — Tue, 27 Oct 2026 06:46:18 GMT

Part Number: OPA4170

Hi TI Team,

We are using the OPA4170AIPWR in our Base DIO input circuit. When no external input is applied, the input node is pulled high to either 12 V or 24 V through the pull-up network. However, we are observing only ~8 V at the input node instead of the expected voltage.

Based on the attached schematic, the measured voltages are approximately:

Input node (BASE_DIO_3): ~8 V
Non-inverting input of OPA4170: ~7.5 V
Inverting input of OPA4170: ~2.2 V
Op-amp output: ~11 V
BASE_DI_3: ~3.45 V

Could you please help us understand:

What could be causing the input node to stabilize at ~8 V instead of the expected 12 V/24 V when no external input is connected?
Is the OPA4170 input structure, bias current, input protection circuitry, or any other internal mechanism contributing to this voltage drop?
Are there any concerns with operating the op-amp inputs under this condition?
What would be the recommended method to rectify this issue and ensure the input node reaches the intended pull-up voltage?

The relevant schematic snippet is attached for reference.

Thank you for your support.

TAS2573EVM-DOC-CERT: The PurePath™︎ Console 3 Application

zhou zhanshi — Tue, 27 Oct 2026 05:50:01 GMT

Part Number: TAS2573EVM-DOC-CERT
Other Parts Discussed in Thread: TAS2573

Our Redtail product is used the TAS2573 Amplifer,need the PurePath™ Console 3 tool to adjust the audio data,please supply it to us

TLV9352: Question: For the TLV9352IDR, in the following cases, is it considered a process issue or oxidation?

DANFANG HONG — Tue, 27 Oct 2026 01:37:33 GMT

Part Number: TLV9352

Hi,
We are currently facing the following issue and would appreciate your help in answering it:
When the original package and sealed anti-static bag were unopened, we opened 3 chips and found that 1 of them had slight yellowing on the pins (as shown in the picture).
Could you please let us know if this is a process-related issue or oxidation? Would it affect usage?

TL331B-Q1: Requesting Level 2 PPAP

Federica Interrante — Mon, 26 Oct 2026 23:50:05 GMT

Part Number: TL331B-Q1

Hello, I am a parts engineer for Northrop Grumman and am looking for a level 2 PPAP for part number TL331BQDBVRQ1. Typically, I can request this data on your site but the online form is currently not working. Acquiring this data would assist us in convincing our customers to use this part in multiple designs.

LM139AQML: PIND Cavity Height

Brian Armenta — Mon, 26 Oct 2026 20:08:15 GMT

Part Number: LM139AQML

Hello, We purchase LM139AQML and we need the cavity height to establish appropriate PIND test conditions. I reviewed the datasheet but couldn't find anything about the cavity height. Could you provide the internal cavity height, including nominal value and tolerance or minimum/maximum limits, with units for this part.

INA181: Failure mode

William Deshaies1 — Mon, 26 Oct 2026 19:53:15 GMT

Part Number: INA181
Other Parts Discussed in Thread: TPS63802

Hello,

I would like to confirm a possible failure mechanism with the INA181A1IDBVR.

Setup:
- VS is supplied from an MCU GPIO (3.3 V when on, 0 V when off), with 0.1 uF bypass.
- REF is driven by a DAC (MCP47CVB02) at 0.5 to 1.65 V, and stays driven while VS is off. The DAC can source 6 to 14 mA into a short.
- IN+/IN- sit across a 0.05 ohm high-side shunt at 0 to 5.9 V.
- OUT drives the FB pin of a TPS63802 to regulate LED current.

After some time in the field, one device's output stays at 0 V regardless of sense current.

Questions:
1. With VS = 0 V and REF at 0.5 to 1.65 V, does current flow into REF through an ESD structure to VS, and roughly how much would it be?
2. Can this condition cause latch-up or damage when VS is then applied?
3. Is an output stuck at 0 V consistent with that kind of damage?
4. Would a 1 to 2 kohm series resistor on REF be an acceptable fix, and what effect would it have on gain error and CMRR?

Thank you,

William Deshaies

LM2903B-Q1: Request for Confirmation of ICTS Regulation Applicability

Bruce Li — Mon, 26 Oct 2026 07:17:55 GMT

Part Number: LM2903B-Q1

Hi E2E Team,

Good day.

Custome ask below quetion:

[Request for Confirmation of ICTS Regulation Applicability

As the CCO for LM2903BQDGKRQ1 is conducted in China, our customer has requested confirmation as to whether this product is subject to ICTS regulations.

We would appreciate your review and confirmation.

Thank you in advance for your support.]

When I ask GTC team, they let me to connect with the product line team.

Snow case No. is CS3612953
Best Regards,
Bruce Li
Texas instruments | Customer Support Center

AMC23C10: AMC23C10 Switching Characteristics

shuhei hayashi — Mon, 26 Oct 2026 07:15:21 GMT

Part Number: AMC23C10

Hi All,

The voltage VDD2 for each item in section 6.10 Switching Characteristics of the AMC23C10 datasheet is 3.3V.
Please kindly tell us the frequency response values when VDD = 5.0V.
In other words, would you kindly tell us the MIN (ns), TYP (ns), and MAX (ns) values for "PUSH-PULL OUTPUT" and "OPEN-DRAIN OUTPUT"?

Best Regards,
Shuhei Hayashi,

AMC23C10: AMC23C10 Trip threshold error

shuhei hayashi — Mon, 26 Oct 2026 07:12:34 GMT

Part Number: AMC23C10

Hi All,
Would you kindly tell us the meaning of Trip threshold error under COMPARATOR in section 6.9 Electrical Characteristics of the AMC23C10 datasheet.
I understand it as follows. Please kindly tell me whether my understanding is correct.
1)INN=GND1=0V. Is it correct?
2) In the theoretical case, the following threshold formula applies.
VIN+=VINN+VHYS/2 = 0V +25mV/2= 12.5mV
VIN-=VINN+VHYS/2 = 0V - 25mV/2= -12.5mV
The "Trip threshold error" range is from -6mV to 6mV.Therefore, I believe the following formula applies.
VIN+ = 12.5mV ±6mV= 6.5mV to 18.5mV
VIN- = -12.5mV ±6mV= -18.5mV to -6.5mV
The above represents the variation of the AMC23C10 comparator itself.
In other words, VIN+ varies from 6.5mV to 18.5mV, and VIN- varies from -18.5mV to -6.5mV. Is this correct?

Best Regards,
Shuhei Hayashi,

INA241A: Customer needs to provide INA241A3QDRQ1 qualification summary

Bruce Li — Mon, 26 Oct 2026 05:21:33 GMT

Part Number: INA241A

Hi E2E Team,

Good day.

The customer wants the qualification summary for INA241A3QDRQ1 that can't be found on ti.com,

So, Could you please help to provide it ?

Thank you so much.

Snow case No. is CS3655461

Best Regards,

Bruce Li

Texas instruments | Customer Support Center