Quantcast
Channel: Power management forum - Recent Threads
Viewing all 35901 articles
Browse latest View live
↧

LM5069: No latch-off at over 3A load

July 31, 2019, 11:27 pm
$
0
0

Part Number: LM5069

Hello E2E,

Our customer is using LM5069-1. They ware set to >2A over-current limit.
However, when over-current nier 3A, LM5069-1 don't latch-off, to be retry.

Does TI able to find any cause from schematic?

Regards,
ACGUY

(Please visit the site to view this file)

↧
Search

TPS92691: 6.3W LED fail issue

July 31, 2019, 11:30 pm
$
0
0

Part Number: TPS92691

Hello

     Customer found our 6.3W LED device can’t be work normal. But 55W device seems ok.They make some modify on EVM board likes attached circuit BOM value.

But PR16 change to 150k and PR22 POP. Just using IADJ(Analog dimming).

Please check the circuit and waveform if any customer can try.

If this solution can’t be support CV mode they may consider to change solution. Has any comments for 6.3W LED fail issue？ Thank you. 

 

Our device spec show as below.

  1. LED 55W; CV mode 24V, 2.26A
  2. LED 6.3W; CV mode 24V, 0.26A

 

BR

Patrick

               

↧
↧

TPS56221: about input capacitor

July 31, 2019, 11:39 pm
$
0
0

Part Number: TPS56221

Hi

My customer has question.

The TPS 56221 specifies 1 uF for noise reduction on the input capacitor in the data sheet.
I'm trying to use 0.1 uF or 4.7 uF because the customer can not use 1 uF. Is there a problem?

Regard

T Kishi

↧

UCD7138: UCD7138

July 31, 2019, 11:48 pm
$
0
0

Part Number: UCD7138

Hello, I am currently studying the SR behavior of PSFB.

I wonder if the PSFB converter can not use the same controller as the UCD7138.

Even though it is not an LLC converter, the PSFB has a section that conducts to the body diode during DCM operation like a flyback,

and I wonder if it is impossible to use because there is no suitable controller.

To summarize, why is the PSFB converter not having a controller to control the SR by measuring the drain-source?

↧

UCC3895: OUTC and OUTD Pulses are not stable and not symmetrical

July 31, 2019, 11:58 pm
$
0
0

Part Number: UCC3895

Dear TI Team

we are designing a 10KW phase shifted Full bridge DC DC controller using IC UCC3895. we did an open loop test by disabling feed back to the controller and we loaded up to 10KW smoothly. Issue reported while we closed the loop. Issues are listed below.

  • At no load output is regulating at 100V and no noise, burst mode is working.
  • When we loaded around 300W( Output voltage 100V and input voltage 200V). Output is regulating at 100V noise is generating from the magnetic parts, while cross checking we observed asymmetrical pwm pulse output(between OUTC and OUTD). we work around as per the application note from TI SLUA275, but still issue not resolved. We increased Ramp voltage to 1.15Vdc by adding voltage divider from Vref output.
  • We tried with compensation circuit still issue not resolved.

We are using a four layer PCB for UCC3895 (as a separate daughter card) separate from power PCB. And a dedicated ground layer given for the IC,  but power ground and analog ground not separated which is common as ground plane.

Please help us to resolve the issue

↧
↧

TPS63001: TPS63001 power consumption in shutdown mode

August 1, 2019, 12:22 am
$
0
0

Part Number: TPS63001

Hello,

how much is the power consumption (µA) from TPS63001 voltage regulator in shutdown mode?

We need this Information before we start an battery powered project.

Thanks.

↧

LM5116: external voltage on Vcc

August 1, 2019, 12:49 am
$
0
0

Part Number: LM5116

Hi team,

Customer want to add external voltage ( 12V)  on Vcc pin of LM5116 . so several questions:

1. can external bias voltage ( 12V ) be added on Vcc pin to make the part work?  From datasheet, it only shows VCCX can be used as external power input.

   If VCC can also works, what's the connection of VCCX, connect to GND? 

2.  if above application can works, then we need some details on

a. is there any sequence requirement on Vin/12V ( external Vcc) /EN?

b. will the 12V flow back to Vin which make LM5116 fails ( may be some function doesn't work) at some condition ?

c. If Vin is short but 12V still there, is there any problem?

Thanks.

BRs

Given

↧

UCC28070: Unknown Value for "K3rd", "Gmv"

August 1, 2019, 12:56 am
$
0
0

Part Number: UCC28070

I am performing the DS Calculations Page 27. I need all information required to perform these calculations. Below are my questions.

 

Reference DS Equations 30 thru 33, Page 27.

Unknown Term “K3rd”, Is this the third harmonic for 60 Hz which would be 180 Hz?

Question 1) Define the unknown term “K3rd”.

Question 2) Is “K3rd” a constant? {Yes or No} If yes, what is the constant value used.

Question 3) Is “K3rd” a variable? {yes or No} If yes:

  1. What is the min/max value.

  2. What are the Test Conditions used to determine these values.

Question 4) Is there any information that is required to determine the correct value of “K3rd” that I have not asked.

 

Unknown Term “Gmv”, Is this the value listed in DS Page 6, 5th line from bottom, (70uS)?

Question 5) Define the unknown term “Gmv”.

Question 6) Is “Gmv” a constant? {Yes or No} If yes, what is the constant value used.

Question 7) Is “Gmv” a variable? {yes or No} If yes:

  1. What is the min/max value.

  2. What are the Test Conditions used to determine these values.

Question 8) Is there any information that is required to determine the correct value of “Gmv” that I have not asked.

↧
Search

TPS1H200A-Q1: TPS1H200A-Q1 Enable Viltage

August 1, 2019, 1:06 am
$
0
0

Part Number: TPS1H200A-Q1

Dear TI Team,

Can I find out what operation is performed when 1.2V is applied to the enable pin of the TPS1H200A-Q1?

High Level min 2V / low level max 0.8V It is specified in the data sheet , and I want to know what kind of symptom will occur when the voltage in the middle range is applied.

please check.

Thanks.

↧
↧

BQ25150: Charge management certification

August 1, 2019, 1:19 am
$
0
0

Part Number: BQ25150

Hi,

I want to add a chargeable battery to my PCB.

Do I need to have my circuit certified if I add a pmic? Does it exist regulation for battery charger such as FCC for RF?

Best regards,

↧

BQ2970: Using BQ2970 as low voltage indicator to put voltage regulator into sleep mode.

August 1, 2019, 1:23 am
$
0
0

Part Number: BQ2970

I would like to use the BQ2970 battery protector to act like a low battery indicator. I am using a voltage regulator which can be put into sleep mode (when a pin is pulled logic LOW - the over discharge mosfet pin would control my regulator perfectly) using a protection IC. I would like to use another device which better suits my application or how I can use this device. The problem I am having is that on the V- pin there will be unexpected behaviour as no MOSFETs are present. Thank you for any help. 

↧

TPS61281A: Could we place two TPS61281A Vout in parallel to support higher current?

August 1, 2019, 1:23 am
$
0
0

Part Number: TPS61281A

Dear Sir,

Our target application is boost-bypass to prevent IC operate at UVLO at the condition of ->  6A Iout continuously with Vsel above 3.15V.

I think below two idea may be options to achieve 6A Iout.
Please have you recommendation to us, thanks.


a. Could we place two TPS61281A Vout in parallel to support 6A or higher current?
b. Is there a part could support 6A Iout continuously?

Thanks.

↧

TPS40057: TPS40057 protection questions

August 1, 2019, 1:51 am
$
0
0

Part Number: TPS40057

Hi Support team 

We use the follow OVP protection circuit, when the 5VSB rise TO OVP happen , Make the SS/SD become low level,

 

We want to know the 5VSB whether can work like attached 2 waveform when the 5VSB OVP protection removed?

 

Note:

When we test the OVP, through short the VFB PIN to let the 5VSB rise to OVP happen.

↧
↧

TPS3700: Cheaper alternative

August 1, 2019, 2:03 am
$
0
0

Part Number: TPS3700

Hello team,

I would need a voltage supervisor to verify that the input stage with 12V..250V input rail is generating an output voltage of at least 7V (generally between 7 and 10V).

I noticed that the TPS3700 is a good candidate but too expensive, TLV809 is cheap but limited in voltage range (would avoid voltage partition if possibile); do you have any alternative?

Please let me know your thoughts.

Thank you and best regards,

Adrian

↧

WEBENCH® Tools/LM5022: LM5022 SEPIC topology

August 1, 2019, 2:29 am
$
0
0

Part Number: LM5022

Tool/software: WEBENCH® Design Tools

Hi,

We are considering LM5022 at SEPIC topology with the following conditions.

Vin=10V~36V, Vo=12V, Io=3A

At the beginning of the considering , we simulated at WEBENCH. However the inductor was larger than expected.(180uH)

On the other hand, we tried another device such as TPS40210. The inductor was small.(15uH)

Why is the indcutor different with LM5022 and TPS40210?


I understand the inductor is depended on the switching frequency.In the case of LM5022 , the freq is 100kHz. In the case of TPS4021, it was 370kHz.

(We tried to change the freq of LM5022. But it couldn't ) Why the value is so different between LM5022 and TPS40210? What kind of parameter or spec of the device is related ?

Best Regards,

Koji Hamamoto

↧
Search

BQ24297: DPM

August 1, 2019, 2:31 am
$
0
0

Part Number: BQ24297

Hi Experts,

Can BQ24297 disable the DPM?

Best Regards,
Fujiwara

↧

TLC6C5712-Q1: ERR (open-drain) pull-up while Vcc=OFF

August 1, 2019, 2:37 am
$
0
0

Part Number: TLC6C5712-Q1

Hi Team,

My customer asked following question. Could you support on this?

Customer's system turns off VCC of TLC6C5712 while sleep mode, but pull-up supply for ERR output is still active.

In clause 6.1 it describes Max value of "ERR open-drain output" being 7V, so can we say pulling-up with 5V while VCC =OFF is no problem?

Best regards,

↧
↧

Vin and Vout of TPS22860

August 1, 2019, 2:37 am
$
0
0

We have a question about TPS22860.

What happens to the IC when Vout is over than Vin?

Best regards,

Takahiro Nishizawa

↧

LM334: Small Constant Current Source

August 1, 2019, 3:01 am
$
0
0

Part Number: LM334

Hello,

I'm looking for the smallest package of a Constant Current Source to drive some LEDs.

The constant brightness of each LED is important. 

Requirements:

Vin<3.5v

I out max= 5mA

Thanks in advance

↧

Current limit operation of TPS62175

August 1, 2019, 3:22 am
$
0
0

We have questions about TPS62175.

Question 1.

Do you have the data about output characteristics of overload?

For example, waveform or graph of output voltage and output current in overload.

Question 2.

Output current keeps constant and output voltage drops in current limit operation.

Is this understanding correct?

Question 3.

We use TPS62175 and Load SW. 

       16Vin----------- TPS62175----------(5V)--------------Load SW

Inrush current(1A) occurs when soft-start is finished and Load SW enables.

This IC operates current limit and Vout drops.

Is there possibility that the time from starting current limit operation to recovering output voltage 5V fluctuates when load SW repeats turn-on and off at intervals of 15 seconds?

Please check the attached document.

Best regards,

Takahiro Nishizawa

(Please visit the site to view this file)

↧
Viewing all 35901 articles
Browse latest View live
Search
<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>