Logic forum - Recent Threads

LSF0108-Q1: Inquiry Regarding Vref and Pull-up Voltage Configuration for LSF0108QPWRQ1

virali Chhag — Mon, 11 May 2026 13:54:41 GMT

Part Number: LSF0108-Q1

Dear Team,

We are utilizing the LSF0108QPWRQ1 device for MDIO, MDC, and I2C communication protocols. The reference voltages VrefA and VrefB are configured at 1.2V and 1.8V, respectively. However, due to a schematic symbol error, the IO pins are swapped. Both IO pins are currently pulled up with respective resistors.

Currently, IO_A is connected to a 1.8V pull-up with VrefA at 1.2V, and IO_B is connected to a 1.2V pull-up with VrefB at 1.8V.

We seek clarification on whether it is permissible to connect VrefA to 1.2V with a 1.8V pull-up, or if VrefA should exclusively be set at 1.8V. Furthermore, if VrefA is adjusted to 1.8V, will this configuration ensure proper operation with VrefA equal to VrefB? Notably, the B side configuration appears to be functional with VrefB at 1.8V and IO at 1.2V, as depicted in the datasheet schematic.

Please confirm the recommended configuration at your earliest convenience.

TPLD2001: Regarding TPLD2001 Simulation in ICS

Kyohei — Mon, 11 May 2026 08:59:10 GMT

Part Number: TPLD2001

Hi team,

Our customer is considering adopting the TPLD2001 and is currently proceeding with simulation evaluation using ICS.

They would like to have the output operate in conjunction with an external voltage source (XTPLD_OFF), as described below. However, based on the simulation results, the output of the AND gate goes High when one of the inputs (por0) turns ON, and it remains High continuously thereafter.

Could you please help us identify the cause of this behavior?

simulation_test1.zip

Best regards,

Kyohei

TMUX4819: TMUX4819 are deasible for RS232/RS422 MUX to replace MAX14778ETP+

Vincent Chiu — Mon, 11 May 2026 06:57:03 GMT

Part Number: TMUX4819
Other Parts Discussed in Thread: TMUX6209, TMUX6111,

Hi TI experts,

Below is the snapshot of our current design, we wab to replace MAX14778ETP+. We survey TMUX6209, TMUX6111,TS3A50, however, these parts need dual power input to support +/-15V RS232 signal level. Due to we do not have additional rouitng area, need TI's experts to recommend other feasible parts for placement, no need pin-to-pin compatible.

How about two TMUX4819?

Regards,

Vincent

SN74LV165A: marking on the item

Tak Lung Chan — Mon, 11 May 2026 02:24:26 GMT

Part Number: SN74LV165A

Dear Sir/Madam

I'm Noli from Tokyo Electron device.

one of my customer asked they would like to know the meaning of the marking on the item-SN74LV165APWR.(Red sqaure part)

Please advise. Thank you

SN74LVC1G373: schematic review request

pragash sangaran78 — Sun, 10 May 2026 22:54:21 GMT

Part Number: SN74LVC1G373

i would like help to review my schematic for SN74LVC1G373YZPR. i prefer review via PM or email. thanks.

SN74AVC2T245: SN74AVC2T245 DIR

Yuki Ito — Sun, 10 May 2026 01:27:54 GMT

Part Number: SN74AVC2T245

I connected the DIR pin of the SN74AVC2T245 directly to VCCB (+3.3V) instead of VCCA (+1.8V).

It seems to have overvoltage protection, but will this cause any problems?

SN74LVC1G373: need clarification.

pragash sangaran78 — Sat, 09 May 2026 12:46:59 GMT

Part Number: SN74LVC1G373

Latch Enable (LE): output (Q) follows input (D) when high.

With latch input (D) low by a trigger event, the output (Q) holds the previous Q0 data entered until the LE pin is cleared. what it means by LE is cleared? LE is low?

SN74LVC373A-EP: SN74LVC373AQDWREP

SJ Park — Fri, 08 May 2026 19:58:34 GMT

Part Number: SN74LVC373A-EP

Hi, on the datasheet for SN74LVC373AQDWREP (www.ti.com/.../sn74lvc373a-ep.pdf, I see on the first page that there is a DW-20 SOIC package with P/N SN74LVC373AQDWREP.

However, under the ordering information, I'm not being able to find any DW-20 package options nor on the ordering options on the TI website.

Any thought on this?

Thanks

TM4C123GH6PM: consulta producto

maria aires — Fri, 08 May 2026 16:45:35 GMT

Part Number: TM4C123GH6PM
Other Parts Discussed in Thread: EK-TM4C123GXL

Hola, buenas tardes.

Quiero comprar 10 unidades de la sigueinte referencia.

He encontrado esto en AliExpress: ¡Ayúdame a escoger!
Nuevo Original EK-TM4C123GXL TM4C123GH6PM MCU LaunchPad placa de desarrollo de evaluación en stock envío rápido
https://a.aliexpress.com/_EyHd2Dg

Quisiera saber precio y plazo de entrega a Barcelona, España.

Muchas gracias

TXB0104: Logic Level Triggered Issue

Haresh Prajapati — Fri, 08 May 2026 14:37:38 GMT

Part Number: TXB0104

Hello TI Team,

I am using TXB0104RGYR for bidirectional logic level translation.

Setup Connection:

VCCA = 1.8V
VCCB = 3.3V
A channel and B channel are connected with controller GPIOs
Both GPIO pins remain floating during idle condition
A1 channel monitored using DSO probe

Problem Statement:

When B1 is connected to logic HIGH (3.3V), A1 correctly transitions from LOW to HIGH (~1.8V).
HIGH transition detection works properly.
However, when B1 is disconnected (floating condition), A1 remains stuck at HIGH level and does not return LOW.
Additionally, when the DSO probe is disconnected and again check at A1 then shows LOW logic level correctly
It appears the logic state is being retained/stuck during floating condition

Questions:

Is this behavior expected with TXB0104 during floating input conditions?
Does TXB0104 have issues with floating GPIO connections?
Can DSO probe capacitance affect TXB0104 logic state retention?
Is the internal edge accelerator or weak driver causing the output to remain HIGH?
What is the recommended method to avoid stuck logic condition during floating/disconnect state?
Are external pull-down resistors mandatory for stable operation in this use case?

For reference, I will attach the schematic of my application.

Please suggest the recommended hardware implementation for reliable HIGH/LOW logic detection.

Thank you.

SN74LVTH244A-EP: SN74LVTH244ARGYR Exposed Pad (EP) Connection Recommendation — GND or Floating?

Arvind — Fri, 08 May 2026 10:12:04 GMT

Part Number: SN74LVTH244A-EP
Other Parts Discussed in Thread: 14-24-NL-LOGIC-EVM

Hi team,

Quick check regarding the exposed pad (EP) on the SN74LVTH244ARGYR package.

I reviewed:

Datasheet Section RGY0020A Package Notes 3&4
TI app note ( SLUA271 -QFN and SON PCB Attachment ) Section 3.4
The associated EVM documentation (14-24-NL-Logic-EVM Evaluation Module -SCEU022A ) Section 2.3 Hardware Conclusion

From the datasheet, TI mentions the EP is mainly for enhanced thermal/electrical performance and should be soldered to the PCB thermal pad, but I could not find an explicit statement saying whether the EP must be connected to GND, VCC, or left floating.

Also, in the EVM guide (section 2.3 Hardware Conclusion), TI states:

“Some of the packages have thermal pads which were taken into account with this board design. These thermal pads were either grounded or left floating (depending on clearance constraints) which is the appropriate method for the devices being supported.”

That makes me unsure what is correct specifically for the SN74LVTH244ARGYR.

Can someone confirm:

Is the EP internally connected to anything?
Is it recommended/safe to connect the EP to GND?
Or should the EP remain floating for this device/package?

I could not find a definitive recommendation in the datasheet.

Thanks.

SN74HC595: SN74HC595 Abnormal communication level

Zhen Wang — Fri, 08 May 2026 09:11:55 GMT

Part Number: SN74HC595

When SN74HC595 is in normal communication mode, a 5V voltage comes out from the MCU and enters the SRCLK of SN74HC595, where it only has a 4.8V voltage; when I pull down the MCU, there will still be a 1V voltage on RCLK; Is there any recommended resistance value for the serial path of SPI? The current 10K setting has been changed to 330R, and the voltage has returned to normal. Would you like to ask why this is the case? What caused this?

LSF0204: Digital High and Low

Akshata M — Fri, 08 May 2026 08:46:44 GMT

Part Number: LSF0204

Kindly help share the following values:

VOH, VOL, VIH, and VIL values for LSF0204RUT
VIH and VIL values for TCAL9539RTW
VIH and VIL values for the EN pin of TPS2492PW

SN74LVC1G14: Request for VOH/VOL specifications and design consideration

Hiromu Susami — Fri, 08 May 2026 06:32:47 GMT

Part Number: SN74LVC1G14

Hello experts,

I have a few questions regarding the output voltage specifications:

Could you please provide the following electrical characteristics data?
- VOH(min) at VCC=5.0V, IOH=-10mA
- VOL(max) at VCC=5.0V, IOL=10mA
If these specific values are not available, I would appreciate any guidance such as typical values, or general approach for estimating these parameters.
I noticed that VOH(max) and VOL(min) are not specified in the datasheet. For our design considerations under steady-state conditions, would it be acceptable to assume VOH(max)=VCC and VOL(min)=GND? I understand these values are not guaranteed specifications, but I would like to confirm if this is a reasonable assumption for design purposes.

Thank you for your assistance.

Best regards,
Hiromu

SN74LV1T126-Q1: Request SN74LV1T126QDCKRQ1 FIT & FMD file

Sean Park — Thu, 07 May 2026 23:41:25 GMT

Part Number: SN74LV1T126-Q1

Hello Logic team,

Customer want to check FMD pdf file. Sorry I cannot find from Ti.com

I hope you can share SN74LV1T126QDCKRQ1 device, Functional Safety FIT Rate and FMD pdf file.

LMT87QDCKRQ1

www.ti.com/.../sniu046.pdf

Thank you.

SN54S174: M38510/07105BEA

Emily Elie — Thu, 07 May 2026 18:47:47 GMT

Part Number: SN54S174

Hello - does your mil grade version, M38510/07105BEA, ship in ESD bags?

CD74AC14: Date code cut in for PCN#20240529005.1

Michael Nestor — Thu, 07 May 2026 18:05:14 GMT

Part Number: CD74AC14

For the changes documented on PCN PCN#20240529005.1, dated 5/31/2024, can you advise what date code had the changes cut in? The pcn is dated 5/31/24, and notes a first ship date of 8/29/2024, but doesn't specify a date code cut in.

SN74LVC1G17: Question about Fan-Out capability.

Benjamin Cuebas — Wed, 06 May 2026 14:41:48 GMT

Part Number: SN74LVC1G17
Other Parts Discussed in Thread: SN74AUP1G17, SN74AUC1G17

Fan-out capability is not directly acknowledged in the SN74LVC1G17 datasheet.

I am working on a project where I want to use an SN74LVC1G17 buffer with a VCC of 1.8 V in a 25°C environment. The goal is to use only one SN74LVC1G17 buffer to drive the inputs of 25 SN74LVC1G17 buffers. The input pins of all 25 buffers are wired together. One current‑limiting resistor of a few hundred ohms can be placed on the output of the driving buffer to reduce ringing. The highest data rate required is only 8 kbps.

Are there any issues that could arise from this configuration? Will one SN74LVC1G17 be suitable to drive all 25?

SN74LVC1G125: spec questions and alternative recommendation

Allan Fan — Wed, 06 May 2026 08:47:42 GMT

Part Number: SN74LVC1G125
Other Parts Discussed in Thread: SN74LVC1G99, SN74LVC1G17

Hi experts,

Customer used SN74LVC1G125DCKR and has some questions. To delay the power on/enable timing, they implemented an RC delay on the Enable pin. Since this is a standard CMOS device, when the input voltage is below Vih in the undefined region, the buffer state becomes indeterminate, potentially toggling unexpectedly. Their RC delay is as long as 1 second.

do you see any risks associated with this application?
1.1 The datasheet specifies a maximum Delta t/Delta v of 20 ns/V. Could you explain this requirement? Does it also apply to the ENABLE pin?
Are there any TI pin2pin alternatives that feature a Schmitt-trigger on the enable pin?

BR,

Allan

SN74LVC157A: SN74LVC 157AD: Unable to find Junction temperature in Datasheet

Abhilasha Verma — Wed, 06 May 2026 07:45:06 GMT

Part Number: SN74LVC157A

Hi Team,

I am Unable to find the Tj Juction temprature condition under datasheet for below mentioned IC

Part Number : SN74LVC157AD

Description : QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS

Best Regards,

Abhilasha Verma

CD74HC14: Differences between parts marked with TI symbol or TI text

Steve Miller — Wed, 06 May 2026 02:45:30 GMT

Part Number: CD74HC14

Experiencing performance differences between parts marked with the TI symbol and TI text. What are the differences between parts, e.g., manufacturing site, revision, etc?

TI symbol parts with no issues:

Part Number Markings

CD74HC14M96 23CH5FK-G4-HC14M

CD74HC14MT 01C1P4K -G4-HC14M

CD74HC14MTG4 26AZN2K-G4-HC14M

CD74HC14MG4 28C3YTK-64-HC14M

TI text (no symbol) parts with issues:

CD74HC14M96 TI-58ADHFM-HC14M

SN74HC14DR TI-54CEDERK-HC14

Thanks for your support.

SN54ALS564B: Difference between SN54ALS564B and SN54ALS576B

Marvn Arcangel — Tue, 05 May 2026 13:13:25 GMT

Part Number: SN54ALS564B
Other Parts Discussed in Thread: SN54ALS576B

Hi Experts,

I checked the datasheet of SN54ALS564B and SN54ALS576B and they seem to be identical and can't find any differences.

Can you confirm? what does '64B' and '76B' stands for?

Regards,

Marvin

TXS-EVM: Board Files

Sasha Yakovleva — Tue, 05 May 2026 12:53:15 GMT

Part Number: TXS-EVM

I need the boad files or atleast the dimensions.

Thanks!

SN74LVC1G08: SN74LVC1G08 w/ 5V Level input

William Hu — Tue, 05 May 2026 08:15:44 GMT

Part Number: SN74LVC1G08

P0V82_PGOOD and P1V15_PGOOD are pulled up to P5V with 440k ohm resistors from the PWM, and they are connected to the inputs of the SN74LVC1G08. With VCC = P3V3, the device outputs a P3V3-level signal. Is it still appropriate to use the SN74LVC1G08 in this configuration?

SN74LVC1G17: TO: TI RD& Customer Team-Please confirm picture(1)(2) sample specification FM: Hanpin Procurement Team

宗慶林 — Tue, 05 May 2026 05:32:10 GMT

Part Number: SN74LVC1G17

Please help confirm the sample specifications shown in Photos (1) and (2), as they look very similar.

HP item:417-DDJLE-1078->TI item: SN74LVC1G17DCKR,SC70

HP item:417-HX500-1283->TI item: SN74LVC1G04DCKR,SC70-5P

Best regards,

Cliff Lin

Procurement

Hanpin Electronics Industrial Co., Ltd