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TINA/Spice/TPS92692-Q1: Sim Model Not Boosting to give constant current output

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Part Number: TPS92692-Q1

Tool/software: TINA-TI or Spice Models

Hello Team,

My customer is having trouble with the TPS92692-Q1 simulation model where the output isn't boosting to a high enough voltage to get the expected current running through the LED string.

It seems that the boost fet gate drive will only run in short pulses and turn off instead of boosting up to the expected voltage. Also the Fault output seems to trip for very short periods of time.

I've attached the simulation model, the calculation sheet used for the design, and an example that the model is outputting.

Any suggestions on what we can change to get this working?

So far I've tried:

- Replacing the boost fet with a logic controlled switch

- Replacing the LED model with a string of 18 LEDs

- Removing the dimming FET

Thanks!

David(Please visit the site to view this file)(Please visit the site to view this file)


BQ24610: Battery detection

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Part Number: BQ24610

Hi TI,

I'm testing with BQ24610EVM for 2cell charging.

I have a question about battery detection.

Sometimes a charger cannot charge after inserting a battery. At this time, STAT1 is blinking every 1.7sec.

The battery was connected while input power was being applied.

Refer to below waveform. CH1: Vbat(SRN), CH3: LODRV 

But this issue is solved when TTC pin to ground. (TTC setting:1-2)

Please let me know the reason. 

I just changed the feedback resistor on the EVM circuit diagram for 2cell. (R25: 909K-->300K)

BQ24401: Looking for NiMH battery charger with Q grade

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Part Number: BQ24401

Dear Team,

We are looking for NiMH battery charger with Q grade.

The use case is 5Vin to 4.8V_battery@0.3C charging current. Battery pack spec: NiMH Battery / 4.8V /600mAh

Please contact with me offline if we have this solution in roadmap.< benkuo@ti.com >

Thanks!

Regards,

Ben

TPS92515: Equation mistake in the datasheet calculating exact output current?

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Part Number: TPS92515

Hello,

in the datasheet of TPS92515 (released in August 2016) there is equation 6 calculating the correct output-current if outputvoltage is lower than 10V..:

Iled =[....]-[(Vled*(-RoffCoff(ln(1-Voft/Vled)+tdoff)/2L). I quess this need to be Iled =[....]-[(Vled*(-RoffCoff(ln(1-Voft/Vled)+(Vled*tdoff))/2L)

The last part of the equation (tdoff/2L) isn*t a current yet.

Can you please check?

Regards Matthias

TPS53622: VBOOT

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Part Number: TPS53622

Hi,

I need some info regarding TPS53622:

1) How to set VBOOT voltage through resistor settings ? What value resistor to use ? Or some resistor divider we have to use? Not seen any feedback reference voltage to calculate? Please help.

Do we have a reference schematic, is it shareable?? 

Thanks

Vikas G.

TPS23754: Smooth Transfer Between 12V Adapter

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Part Number: TPS23754

Dear Team,

Base on the below thread.

Can I said I will need TPS23756 to implement 12V adapter and PD smooth transfer without Vout drop?

The customer is looking for two port PD and one adapter reference design.

They need to achieve no Vout drop between 2 PD and 1 adapter plug in and plug out.

Do you have suitable reference design?

Or you have TPS23754 with 12V adapter smooth transfer without Vout drop which we can expand to 2 PD and 1 adapter application?

BR

Kevin

Buck Regulator + Gate Driver in place of HB-LLC (UCC256301) topology

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We want to explore alternate option i.e., combination of Buck Regulator + Gate Driver in place of HB-LLC (UCC256301) topology.

 

I request you to suggest the suitable regulator & gate driver IC Model Number, reference design and Evaluation boards for the same.

 

In this regards, I am trying to reach out to you. Please let me know, if there is any details required.

TPS63710: help select output 48V and -48V 250mA solution

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Part Number: TPS63710

We have a product that requires either 24V or 60V input, with two output voltages of 48V and - 48V 250mA. Can you recommend a part for us? You can also use one chip to generate 48V, and another chip to generate - 48V.


LM25180-Q1: Availability

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Part Number: LM25180-Q1

Please can you provide an availability estimate for LM25180-Q1? The device is currently listed as "Preview"

Thanks,

Grant

TPS62120: Question about buck device selection

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Part Number: TPS62120

Hi team,

     My customer need one buck device, which is used to convert 7.2V supply to 3.6V and its output capability should be greater than 50mA. Now TPS62120 is recommended to customer. Could you please help to check is there any other device which has higher efficiency or lower power consumption? Thanks a lot!

Best Regards

Zhengquan Lu

TPS2493EVM-002: Ciruit matching

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Part Number: TPS2493EVM-002

Hi

we want to use TPS 2493 in our new design.

Kindly share me matching ciruit for 28V Vcc.

Regards 

Pradeep Saklani

TPS61089: Question about the peak current limit and disable function

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Part Number: TPS61089

Hi team,

    My customer would use TPS61089 device to convert (2.7~7.2)V supply to 11V. According to the datasheet, the minimum current limit at the worst case can be 0.8A lower than the calculated value. So if the limit current is 100mA, the calculated peak current limit (ILIM) should be 900mA. Is it correct?

    In addition, when use disable function, if output is open, is there any issue or notice? Thanks a lot!

Best Regards

Zhengquan Lu

LM3466: MTBF Data

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Part Number: LM3466

I am using this part in a design and I want to get the reliability data for it.

More specifically, the MTBF data for this IC.

UCD3138: UCD3138

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Part Number: UCD3138

I am afraid, the attached questions might have gotten buried because I did not perhaps put them at the right place.

Could someone find answers for these?

appreciate.

robin(Please visit the site to view this file)

TLC5947: Pin Status at Power On

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Part Number: TLC5947

Hello,

I am using TLC5947DAPR in my current design.

I have connected BLABK, SCLK, SIN and XTAL signal to controller through Level Shifter and put the Pull up resistor (3.3V) on BLANK Signal in Controller Board.

At Output, I have placed Pull Up resistors (Pin#5 to 23) and connected to MOSFET through Inverter to keep the MOSFET OFF in default condition but some how when I power ON, the MOSFETs are ON for some time and then OFF.

I want to know the output pin condition of TLC5947DAPR at Power ON, here I have kept the BLANK pin High from controller board.

Kindly share the actual working condition of TLC5947DAPR at power ON i.e the status of each pins.

Please find the below Image for your reference.

Regards,

Alpesh

 
 

  


BUF16821: Standard values

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Part Number: BUF16821

Hi, i'm wishing to repair a TV screen, my questions are: this chips comes with a common standard gamma curve values? I ask you because i think i have bought a fake chip, when it comes without blister my balls start to turn.. if it comes with no values, all blank, is there a standard common curve suitable for most of the screens and if yes where them are available? THANKS!! (MUCH IMPORTANT FOR ME).

TPS54531: Ringing frequency at SW output pin

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Part Number: TPS54531

Hi,

I have designed a 12V to 5V and 12V to 3.3V buck conversion using TPS54531. 

Input voltage: 12V nominal

Input minimum: 11.5V

Input maximum: 12.5V

Please find the attached schematic images

While measuring the input and output waveforms following issues were found (Please find the attached waveforms)

  • Input wave form after the Pi filter is more distorted compared with that of before the filter
  • Ringing frequency observed on the SW output pin

By analyzing the SW pin waveform the regulator seems to be operating in the discontinuous mode of operation.

Kindly suggest how to make the regulator to operate in continuous mode 

Also help out in solving the above issues

Thanks in advance

BQ25120: watchdog timer reset device despite I2C read/writes every second (interrupt driven)

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Part Number: BQ25120

I have the BQ25120A in a board and am having a lot of difficulty with it.  First I need to address the watchdog timer, which is resetting the device every 50 seconds despite my conducting I2C reads every second (interrupt driven).  This transaction is rated "NRF_SUCCESS" by the NORDIC '840 firmware so I believe it is actually happening.  There are other issues but I need this one solved before moving onto them.

TPS1663: TPS1663 Current Monitor

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Part Number: TPS1663

Can you tie together the current monitor pins of two TPS1663 (Imon) devices together and expect a sum of the two current sources?   My load is a simple resistor to ground buffered with a high impedance instrumentation amplifier.

LM25066A: How to decrease the instaneous overshot of input voltage on LM25062/6

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Part Number: LM25066A

Hi Team:

  There is an potential system risk if using 2 separated Hotswap  LM25062 to produce P12VA and P12VB(PSU_P12V_VIN ---->P12VA&P12VB):

 

Since 2 large current Efuse share one common 12VIN, OV or Over current fault may be triggered when one rail short to GND. You can see the overshot of P12V_VIN may up to 15V.

So any solution could avoid this risk? How to decrease this instantaneous overshot? using A TVS or other solution to decrease it.

Thanks!


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