Power management forum - Recent Threads

TPS653860-Q1: Full technical design and development support

VINOD SAINI — Thu, 01 Oct 2026 11:56:14 GMT

Part Number: TPS653860-Q1

Hi TI team,

We have selected AM2612 uC for our functional safety application and targetting for SIL-3/SIL-4. This TPS653860-Q1 IC is suggested by TI for safety applications for SITARA family microcontrollers. So we need full support for

TPS653860-Q1 full technical details, its programming, hardware design, devlopment and troublshooting.

Thanks and regards

Vinod Saini

Principal Engineer

RE: TPS653860-Q1: Full technical design and development support

VINOD SAINI — Mon, 05 Oct 2026 09:10:46 GMT

Hi Katie,

Now my company is listed in myTI account. Could you please provide me access to all of the technical datasheets and necessary documents and software for programming this PMIC TPS653860-Q1.

Regards

Vinod

TPS62802: Schmitt input at EN pin

Infant Jesuraj Francis — Fri, 02 Oct 2026 12:11:05 GMT

Part Number: TPS62802

Hi,

We are planning to use RC delay on the enable pin of TPS62802 for power sequencing, R is 4.7kohm and C is 100nF with 2.2RC of around 1ms.

It is not clear if the EN pin is schmitt input. Please confirm a slow changing signal (1ms) can be connected to the EN pin.

Thanks, Jesuraj

RE: TPS62802: Schmitt input at EN pin

Josef Marsmann — Mon, 05 Oct 2026 09:09:13 GMT

Hi Jesuraj,

According design, we don't expect an issue with your RC delay of 1ms.

Best regards,
Sepp

RE: LM27762: LM27762 OUT- not starting

Josef Marsmann — Mon, 05 Oct 2026 09:07:32 GMT

Hi Patrice,

The layout looks good now. Let's start the production.

Best regards,
Sepp

LM27762: LM27762 OUT- not starting

Patrice Vigier — Sun, 13 Sep 2026 17:23:07 GMT

Part Number: LM27762

Hello,

I have two boards using the same schematic. One board correctly generates +2.7 V and -2.7 V, while the other one fails to generate the -2.7 V rail.

Below is the layout of the board that does not work correctly:

Interestingly, I can make the -2.7 V rail start working by placing a very small piece of aluminium foil, approximately 2 x 2 mm, on the bottom side of the PCB, directly underneath the highlighted via. The foil is not electrically connected to the circuit.

Below is another PCB version with a very similar layout, but this one works correctly:

Here is the schematic:

I am using X7R ceramic capacitors.

The trace widths are 0.254 mm, 0.305 mm and 0.40 mm.

The via drill diameters are 0.50 mm and 0.30 mm.

Could you please help me understand what might be wrong with the first layout, especially considering that such a small piece of unconnected aluminium foil is enough to make the negative rail start?

Thank you.

LM5176-Q1: LM5176 output drops some times then restore when cold start-up

Michael Huang — Mon, 05 Oct 2026 01:05:56 GMT

Part Number: LM5176-Q1

Hi TI Expert,

LM5176 schematic as below, Vin=9~32V, Vout=16V.

A sample part returned from the factory shows this phenomenon. With Vin=12V and a light load (around 0.17A) during cold start, the Vout output is normal for several tens of milliseconds, then the output voltage drops, and then recovers. After repeating this several times, the output returns to normal.

Oscilloscope measurements on Vout (PRE), SW1, SW2, and the current on the power supply harness show that before Vout drops, the current starts to rise slowly, then quickly spikes to 13.8A. During this time: the low level time of SW2 increases from 0.4us to 0.7us, then to 1.4us (the load doesn't change during this period); SW1 stays high (12V); the COMP voltage increase slightly at the beginning.

We tried adjusting the Cslope capacitance, but it didn’t help much; when the board temperature is high, the number of voltage drops decreases; since there’s no DC differential probe, we haven’t checked the CS-CSG differential voltage for now.

The question is, why does the low-level time of SW2 get longer even though the load hasn’t changed?

Please share your analysis advice, thanks!

RE: LM5176-Q1: LM5176 output drops some times then restore when cold start-up

Brigitte — Mon, 05 Oct 2026 09:02:07 GMT

Hello Michael,

Is this one sample out of the production where a lot of other samples work as expected?

Is PRE the output voltage? If yes, please measure the input voltage as well. It is possible that the input voltage decreases which could explain the spiking of the current.

Can you please zoom in to the point where the current starts to increase?

LO2 seems to increase because the output voltage drops and the converter tries to increase the duty cycle.

Best regards,
Brigitte

TPS2121: Trouble with input switching

Daisuke Higa — Wed, 16 Sep 2026 04:49:23 GMT

Part Number: TPS2121

Hi support team.

My customer is having trouble with input switching.

The conditions are as follows.

Device in use: TPS2121

Input 1 (primary): 5 V

Input 2 (secondary): 12 V

After stopping input 1, it does not switch to input 2 and drops a lot.

Which part is wrong?

The following is the result of experiment using EVM. Please advise.

Best regards,

RE: TPS2121: Trouble with input switching

Bandaru Hemanth — Mon, 05 Oct 2026 09:02:03 GMT

Hi,

I found the issue device is hitting TSD in this rounded region, the inrush during switching would be

= (coutF) *((12 - 5)/tsw) + VOUT/RLOAD so this current is too high to hit current limit & TSD one after other. the thing here is load current increases as VOUT powering up during switching so the power dissipation keeps on increasing even though device tries to start up in currrent limit so it will hit TSD.

so, the problem is when the device switching from lower voltage to very higher voltage in XREF mode & with very high load current it will current limit & TSD.

the only solution is reducing the load as much as possible or reduce the voltage between VIN1 & VIN2 during switching.

thanks,

Hemanth.

RE: UCG28828EVM-094: UCG28828 / UCG28828EVM-094: Request for Hardware Design Files (Schematic, PCB) & IC CAD Symbol, Footprint, and 3D Model

Rohan Singhal — Mon, 05 Oct 2026 09:00:59 GMT

Hi Anita Yadav ,

Thank you for sharing the CAD Files.

UCG28828EVM-094: UCG28828 / UCG28828EVM-094: Request for Hardware Design Files (Schematic, PCB) & IC CAD Symbol, Footprint, and 3D Model

Rohan Singhal — Thu, 01 Oct 2026 10:31:45 GMT

Part Number: UCG28828EVM-094

Hi TI Team,

We are currently working on a custom power supply design based on the UCG28828 high-frequency quasi-resonant flyback converter and are using the UCG28828EVM-094 evaluation board as our reference hardware.

To help accelerate our custom board layout and design phase, could you please provide or share the download link for the following design assets?

UCG28828EVM Hardware Design Source Files:
- Native schematic & PCB layout source files
- Full Bill of Materials (BOM) with manufacturer part numbers
- Manufacturing Gerber files
UCG28828 Component CAD Library:
- Schematic Symbol
- PCB Footprint / Land Pattern
- 3D Mechanical CAD Model

Thank you for your support!

Best regards,

Rohan Singhal

Botlab Dynamics Pvt. Ltd.

UCC28600: Using UCC28600 Flyback based 200W SMPS

Vivek Sen — Mon, 05 Oct 2026 08:55:17 GMT

Part Number: UCC28600

Hi Team,

I need support for my 200W output Flyback SMPS based on TI UCC28600 IC.

let me know how may i proceed for transformer design with multiple outputs i.e. 7 outputs.

ETD442215 my core selection, what is the switching freq for this.

RE: UCG28828EVM-094: UCG28828 / UCG28828EVM-094: Request for Hardware Design Files (Schematic, PCB) & IC CAD Symbol, Footprint, and 3D Model

Anita Yadav — Mon, 05 Oct 2026 08:51:59 GMT

Hey Rohan,

Sorry, unfortunately due to TI selective disclosure policy, I cannot share EVM complete GERBER file, but kindly find the CAD file for device attached below.

e2e.ti.com/.../UCG28826.zip

UCG28826 and UCG28828 are P2P.

Thanks

Regards

Anita

RE: TPS564252: Phase Margin / Output Filter Double-Pole Frequency

Takashi Imai — Mon, 05 Oct 2026 08:30:21 GMT

Hi Usha-san,

Thank you for your support. I look forward to hearing from you soon.

Best Regards,
T.Imai

TPS564252: Phase Margin / Output Filter Double-Pole Frequency

Takashi Imai — Mon, 05 Oct 2026 02:23:29 GMT

Part Number: TPS564252

Hello,

I have received the following technical question from a customer regarding TPS564252.

The customer is designing a 12-V input to 5-V output power supply using TPS564252 and plans to use the same external component configuration (inductor, capacitors, resistors, etc.) for two load conditions:
VIN = 12 V
VOUT = 5 V
IOUT = 2.52 A
IOUT = 0.996 A

The customer is reviewing the guidance in Section 8.2.2.3 "Output Filter Selection" of the datasheet and noted the following statements:
The output LC double-pole frequency is recommended to be approximately 20 kHz so that the phase boost provided by the internal high-frequency zero provides adequate phase margin.
The crossover frequency is usually targeted to be less than one-third of the switching frequency.

Since WEBENCH does not provide phase margin information, the customer would like to understand how loop stability should be evaluated.

My current understanding is as follows:

TPS564252 uses D-CAP3 control with internal compensation.
Phase margin and loop gain characteristics are not provided in the datasheet or WEBENCH.
Stability is ensured by selecting the output filter components within the recommended operating range and by placing the LC double-pole frequency around 20 kHz as described in the datasheet.
In practice, transient response evaluation is used to confirm stability rather than checking a specified phase margin value.

Could you please confirm whether the above understanding is correct?
In addition, could you please advise on the following points?

Is there any way to obtain phase margin information (simulation model, internal characterization data, etc.) for TPS564252?
Is there a recommended allowable range for the output LC double-pole frequency around the "approximately 20 kHz" guideline? For example, is there any recommended or acceptable frequency range that customers can use as a design target?
Are there any additional stability-related design criteria that should be communicated to the customer beyond the recommendations already described in Section 8.2.2.3 of the datasheet?

Thank you for your support.

Best regards,
T.Imai

TPSM843620: About EN Control

takahiro higuchi — Thu, 03 Sep 2026 09:25:25 GMT

Part Number: TPSM843620

Hi team,

I am planning to control the TPSM843620 using the EN and PG signals.
Is the following circuit configuration feasible?

To prevent unintended operation caused by the internal current source on the EN pin when the power is turned on, is it possible to add a pull-down resistor to the EN pin?
Or would it be better to take a different approach?

Best regards,

RE: TPSM843620: About EN Control

takahiro higuchi — Mon, 05 Oct 2026 08:27:09 GMT

Hi team,

Thank you for your response.

My explanation wasn't very clear.
I was worried that current might flow backward from the EN pin into the external pull-up resistor.

I think the best way to ensure that current definitely doesn't flow backward from the EN pin is to use a voltage divider with VIN—is that correct?

Best regards,

RE: LMR51450: Thermal management and PCB layout advice

Sourish Nandy — Mon, 05 Oct 2026 08:18:46 GMT

Hello Phil,

If efficiency is 87.5%, then the issue of overheating is based on the R_thetha_J of the PCB.

It is higher, which is causing the overheating even with loss % as low as 12.5%.

So, we need to revise the layout to reduce the R_thetha_J of the board.

Also, kindly check that the device is soldered properly on PCB with the DAP on the back of the IC evenly soldered.

Regards,

Sourish

LMR51450: Thermal management and PCB layout advice

Phil Rittenhouse — Sat, 19 Sep 2026 22:49:36 GMT

Part Number: LMR51450

Hi,

I have built a small DC-DC converter around the LMR51450 with the goal of outputing up to 5A at 5V. Unfortunately the chip is running hotter than I would like (110C at 3.1A) (see attached thermal image). Since it is hitting 110C on the case at only 3.1A, it seems unlikely it will handle 5A for any length of time.

I am using 2oz copper for the PCB. I have attached my schematic and top and bottom layers for review. Can you suggest any improvements I could make to improve the thermal performance? Is my goal of 5A reasonable?

Best regards,
Phil

5V_demo-B_Cu.pdf 5V_demo-F_Cu.pdf 5V_demo-Power.pdf

RE: LMG5126EVM: PGOOD Behavior and Output Response During Overcurrent Conditions on LMG5126

?? ?? — Mon, 05 Oct 2026 08:04:47 GMT

Thank you for your explanation.

I will check whether the dip occurs repeatedly when the converter is kept running.

I appreciate your support. If I have any further questions, I will post them in a new thread.

Best regards, Shunsuke

LMG5126EVM: PGOOD Behavior and Output Response During Overcurrent Conditions on LMG5126

?? ?? — Tue, 29 Sep 2026 05:24:16 GMT

Part Number: LMG5126EVM

As stated in the title, I would like to understand the behavior of the LMG5126 when an overcurrent condition occurs.

The waveforms below were captured while operating the device with an electronic load in CR (Constant Resistance) mode and intentionally drawing an overcurrent.

There are two waveform screenshots attached:

The first waveform shows the condition where the load current is significantly higher than the configured current limit.
The second waveform shows the condition where the load current is only slightly higher than the configured current limit.

Is it correct to understand that this PGOOD behavior is caused by the overcurrent condition?

If so, does the device behavior correspond to the output voltage dropping back to approximately the input supply voltage and then attempting to recover to the configured boosted output voltage?

I would appreciate it if you could provide more details about the behavior when PGOOD goes LOW. In particular, I would like to understand what internal protection mechanisms are activated and how the converter is expected to operate after PGOOD is asserted LOW.

Thank you for your support.

TPS562209: VFB input current limits

Matthias Thomas — Mon, 05 Oct 2026 07:50:11 GMT

Part Number: TPS562209

The datasheet specifies a maximum VFB input current of ±0.1 mA at 25 °C.
Is this value correct?

RE: TPS562209: VFB input current limits

Alla Ushasri — Mon, 05 Oct 2026 08:01:24 GMT

Hi Thomas,

Will check and get back to you!

Regards,

Usha

RE: TPS564252: Phase Margin / Output Filter Double-Pole Frequency

Alla Ushasri — Mon, 05 Oct 2026 07:59:51 GMT

Hi,

Will check and get back to you!

Regards,

Usha