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TPS61163: Standard Application - No Switching

February 20, 2019, 4:22 pm
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Part Number:TPS61163

Hi, 

I'm using TPS61163 on a new design using a 8LEDs per String, 2 String LCD.

I see switching at the immediate start or after toggling the enable pin high, but after a few cycles the part seems to be disabled & our 5V input power, is passed through to our LCD anode instead of a boosted voltage.


I'm hoping someone can point me in the right direction of where to look, as the micro bga pins make it hard to debug.
The part does not seem to be going into a protection mode, as I would expect the part to start switching again after the appropriate amount of cycles have passed, but this is not the case. 

Is there any way to find out the status of the LED string in the display?
I expect that 0V on one of the feedback pins means the LED string is open, while a voltage about equal to the SW pin, would mean that LED string is shorted...
So, is there a voltage I can expect to see there, or do I need to measure the current to truly get idea of the LED string's status?


Can Vin, En, and PWM all be brought up High at the same time, such that connecting them all to our 5V input power, would put the part into normal operation when the 5V supply is turned on?
On the PWM timing diagram it shows Enable and PWM pins start low and are brought up high after a bit of time, is this necessary?

I appreciate any help,
Daniel Abbate

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LM5019: Efficiency variation max/min

February 20, 2019, 4:31 pm
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Part Number:LM5019

Hello,

There is a efficiency graph in figure 1 of datasheet. When 48Vin 100mAoutput, we can read the efficiency is around 80%.

In this configuration, how much efficiency is varied? We care about power consumption so we would like to know it.

Best regards,

Toshihiro Watanabe

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UCC28070: Low-pass filter design criteria for CSA and CSB

February 20, 2019, 4:50 pm
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Part Number:UCC28070

On your schematic 1401.Sch-1.pdf(TIDA-0130) for resistive current sensing, there are low-pass filter (R20, R26, C23, C13).
Can you please explain why the low-pass filter with RC=220ns is inserted?
What kind of noise are you trying to attenuate?

Best regards,
Itoh

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UCC28710: Meaning of equation 7 on the datasheet

February 20, 2019, 5:12 pm
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Part Number:UCC28710

Hello,

Can you please explain the physical meaning of equation 7 on the datasheet on UCC28710?

I don't understand why there's square of K_AM.

Regards,

Itoh

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CCS/TPS544C20: How to modify the output voltage by software

February 20, 2019, 5:20 pm
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Part Number:TPS544C20

Tool/software: Code Composer Studio

dear:

    

       Our customer is doing four corner test in our Lab . they want to modify the TPS544C20 output voltage by PMBus write registers .Could you give us a way how to modify the output voltage(such as  if  want the output 0.95V instead of 1.0V)? which register need to be set?  if you have some example code or configuration document, Thanks

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WEBENCH® Tools/BQ4050: 13 cells synchronous equalization problem

February 20, 2019, 5:45 pm
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Part Number:BQ4050

Tool/software: WEBENCH® Design Tools

We are 13 cells synchronous equalization problem, we use 4 bq4050. The first 4050, read four cores; only these four equalizers, the second, the third and the four 4050 are read three cells respectively, total of 13 cells, but also can only correspond to several cells equalization, can not be synchronous equalization together with 13 cores.

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LP5569: Should both status bits,"startup_busy" and "engine_busy" be checked to confirm whether user setting is finished internally or not?

February 20, 2019, 5:55 pm
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Part Number:LP5569

 Hello guys,

 One of my customers is evaluating LP5569 for their next products.

 They have a question as the follow.

Q. Should both status bits,"startup_busy" and "engine_busy" be checked to confirm whether user setting is finished internally or not? 

     Or should either of those  be checked? (startp_busy only O.K?).

 Your reply would be much appreciated.

 best regards,

 Kazuya Nakai.

 

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LP5569: PWM Scheme

February 20, 2019, 5:55 pm
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Part Number:LP5569

Hi,

I've two questions regarding LP5569:

  1. This device has two PWM scheme? One is 8-bit PWM which can be controlled via I2C. Another PWM is via EN/PWM pin, correct? and what are the differences?
  2. Can EN/PWM pin be left floating?

Thanks

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TLC5973: SDI pin

February 20, 2019, 6:08 pm
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Part Number:TLC5973

Hi,

I've questions regarding TLC5973

- Can I use GPIO from microcontroller to drive the SDI pin? If no, please advise the appropriate pin to drive it

- Does this device has EVM?

Thanks

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BQ3060: Can't do a Data Flash Write using I2C

February 20, 2019, 6:34 pm
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Part Number:BQ3060

I was able to read the contents of the data flash of my BQ3060 using I2C.

Now I need to write a different value on those blocks.

For example, I need to change the value of "LT COV Threshold" to 4000. 

To do that, I first read the data block by accessing the "Voltage" Subclass

[w] 0x77, 0x00, 0x00

then read the 1st block of data where the LT COV Threshold is

[r] 0x78

the data that I recieved is as follows (in hex)

12 0E E7 0D AC 0E 074 0D AC .. (and so on)

LT COV Threshold is the 2nd and 3rd byte on the above example (equal to 3815)

then I'll replace those bytes that are equivalent to 4000. the new data block would be

12 0F A0 0D AC 0E 074 0D AC .. (and so on)

What would be my commands/data flow so I can write the new value?

Thanks

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BQ40Z80: Current() and AverageCurrent() report time and sample time

February 20, 2019, 6:37 pm
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Part Number:BQ40Z80

Hi TI experts,
 What's the Current() and AverageCurrent() report time and sample time? How to work in lifetimes?

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LP5569: I can do I2C transactions but cannot get any LEDs to turn on

February 20, 2019, 6:47 pm
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Part Number:LP5569

I have this controller designed into my board and am attempting to verify functionality with an Aardvark I2C/SPI - USB device.  The transactions and responses look correct.  I can write the enable  register and see the output power turns on at 1x.  After that I can get no further response.  Setting 1.5x or auto dosen't seem to do anything.  Attempting to turn on any output results in no current being sunk.

I've tried with auto reg incrementing and without.

Here is a sample instruction sequence:

    <i2c_bitrate khz="10"/>  bitrate 10kHz

    <i2c_write addr="0x32" count="2" radix="16">00 40</i2c_write>  enable the part
    <i2c_write addr="0x32" count="2" radix="16">2f 08</i2c_write>  set up the MISC reg

    <i2c_write addr="0x32" count="2" radix="16">22 40</i2c_write>  writing LED current controls
    <sleep ms="500"/>  pause 500 msec
    <i2c_write addr="0x32" count="2" radix="16">23 40</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">24 40</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">25 40</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">26 40</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">27 40</i2c_write>
    <sleep ms="500"/>

    <i2c_write addr="0x32" count="2" radix="16">22 00</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">23 00</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">24 00</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">25 00</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">26 00</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">27 00</i2c_write>
    <sleep ms="500"/>

    <i2c_write addr="0x32" count="2" radix="16">22 8f</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">23 8f</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">24 8f</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">25 8f</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">26 8f</i2c_write>
    <sleep ms="500"/>
    <i2c_write addr="0x32" count="2" radix="16">27 8f</i2c_write>
    <sleep ms="500"/>

Any ideas what I am missing here?

Thanks,

David B

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BQ27542-G1: BQ27542-G1 learning cycle

February 20, 2019, 7:00 pm
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Part Number:BQ27542-G1

Dear TI Engineer,

I read the TRM of bq27542-G1(SLUUB65A–May 2015–Revised May 2016), in C3 of learning cycle of appendix C, it says discharging-Relax-charging-relax-discharging-relax, however, in GPCCHEM

Gauging Parameter Calculator Chemistry matching tool (SLVA725), it says: charging-relax-discharging-relax. I'd like confirm with you which one is preferred 

Thanks.

Mike

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BQ25120AEVM: BQ25120A SYS output voltage is not stable as the user's guide say when the load is connected

February 20, 2019, 7:28 pm
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Part Number:BQ25120AEVM

BQ25120A SYS output voltage is not stable when connected to the load, I connected a load to the BQ25120AEVM, and measured the output voltage, the voltage chaged obviously when I change the load. It was actually 1.767V when the output current is 100mA, but was 1.797V to 1.807V in the user's guide(1.8V programed). So I want to know why it is different ？

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UCC28064A: UCC28064A model

February 20, 2019, 8:03 pm
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Part Number:UCC28064A

Hi, 

Im planning to model the interleaving method and closed loop control used in ucc2806x for my stability analysis excluding other features such as protection circuits. Just the control part. Is there a complete implementation/schematic of just the interleaving control strategy of this product? Thanks

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DCV010505D: Output power is lower than expected

February 20, 2019, 8:16 pm
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Part Number:DCV010505D

Hi,

I made a circuit that uses DCV010505D to get isolated -/+5v output from +5V USB power. When I soldered everything and tested, I found the output was about -/+2V at no load. I don't have the 2.2uF capacitor at the current moment so I paralleled two 1uF ceramic capacitors for the input pin. I don't know if the issue is the wrong capacitor or others. I'm going to buy the 2.2uF capacitor and try it again. But I read that someone has a similar issue from this thread and I wonder whether they have resolved their issue or not. Look forward to your reply, thank in advance.

Thanks

Rui

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LM5060-Q1: OUT pin Sink Current

February 20, 2019, 8:40 pm
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Part Number:LM5060-Q1

Dear, Sir.

My customer is facing a RMA issue.

I tried to simulate using TINA-TI simuation model to clarify the cause.

I am having a several questions through the simuation.

Please give your advice.

1. OUT pin Sink Current.

   I could see the sink current on OUT pin, 2.2mA@EN=Low,80mA@OVP Fault.

   It seems the internal current source is pulling the current from OUT pin.

   Is it a normal behavior?

2. Maximun Sink/Source Current on each pins.

  The voltage robustness are defined on the datasheet for each pins.

  Is it possible to define the maximun sink/source current on each pins?

Best Regards,

H. Sakai

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TPS51285B: About TPS51285B OCL setting...

February 20, 2019, 9:23 pm
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Part Number:TPS51285B

Dear Sirs,

My customer is testing with TPS51285B and want to set up the OCL with attached excel tool.

However, with the result of tool, it seems the OCL value is very large than customer target.

The OCL result got from tool is 29.3A.

Can you help to check what's wrong with it?

Thanks.

Here are customer configuration.

1. 5V/12A output, OCL need to set as 15A

2. 3.3V/15A output, OCL need to set as 16A

3. MOSFET use CSD87350Q5D and TOP RDS 5mΩ，LOW RDS 1.2 mΩ

4. CHOKE is 1.5uH,3.7 mΩ

 

(Please visit the site to view this file)

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LM5041: EVAL board Feedback

February 20, 2019, 9:29 pm
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Part Number:LM5041

Dear Sir,

I wanted to understand the practical advantage of using Capacitor C42 (22nF) from output live to feedback optocoupler.

Also if I configure my output to 3.3V/30A , then in the feedback section TL431 with 2.5V reference or TLV431 with 1.24V reference which will give better regulation and good for a power supply. 

A smaller reference or higher reference which will be better for the feedback section.

Thanks & Regards,

Nesh

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TPS51285B: Abnormal noise at some current loading...

February 20, 2019, 9:42 pm
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Part Number:TPS51285B

Dear SIrs,

My customer is testing with TPS51285B and found some issue about the noise.

Below is the testing result!

while the output loading is around 3~5A, the noise seems large than others current loading.

Please help to check the attached schematics and give me some suggestion.

Thanks. 

(Please visit the site to view this file)

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