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LM3405: LED PWM Dimming Ratio

October 25, 2018, 9:58 pm
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Part Number:LM3405

Hi 

My customer would like to know the mean in the description of datasheet 7.3.5 of LM3405. 

The last sentence says "The dimming ratio reduces drastically when the applied PWM dimming frequency is greater than 5kHz."

Does this mean when PWM is faster than 5kHz, LEDs will lit 100% so no longer dimming?

Regards, NY

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Why Pack Current Calibration is error?

October 25, 2018, 10:11 pm
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Why  Pack  Current Calibration is error? 

Thanks!

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BQ40Z80: lost communacation when setting TSint & TS4

October 25, 2018, 10:24 pm
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Part Number:BQ40Z80

Dear TI Experts,

My customer is evaluating with 4800_0_02-bq40z80.bqz +bqStudio 1.3.86+EV2400+BQ40Z80EVM-020 , after setting TSint & TS4 to 1, the commucation will lost and can't recover. They change a new BQ40z80 sample and do the reproduction test and get the same result. Could you kindly help to give some advice about this case? Is there updated FW for BQ40z80? Thanks a lot.

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UCC21520: Reason for UCC21520A Device failure showing Impedance between INB and GND,VCCI and GND as 52 ohms

October 25, 2018, 10:37 pm
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Part Number:UCC21520

Hi,

I am using UCC21520A as half bridge gate driver IC with 15V Vcc supply.VDDA supply =6.5V(Bootstrap supply  regulated by LDO TPS7a1601).

Device gets failed twice.Both the time,The impedance between INB and GND,VCCI and GND shows 52 ohms.

What can be the reason for the device failure.I ave attached the schematics for your reference.

With regards,

P.Selvam.

(Please visit the site to view this file)

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TPS25200: Rise time

October 25, 2018, 10:54 pm
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Part Number:TPS25200

Hi,

My customer requires that rise time is below 1ms.

If capacitive load is small, can it achieve this requirement?

If yes, how much is the capacitance achieving requirement?

Best Regards,

Kuramochi

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Solar charger circuit for 6 to 24V solar panel to get 5V output and have a lithium battery backup.

October 25, 2018, 11:08 pm
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Hi. I would like some advice on solar charger circuits. We need to be able to use 6V, 12V or even 24V solar panel and get 5V. We also need to use a lithium battery backup. Can you please recommend the design?

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TPS61202: The limit of input current.

October 25, 2018, 11:20 pm
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Part Number:TPS61202

Hi teams,

My customer wants to know ｗhat is the rated value of the peak current of TSP 61202?
The datasheet describe the average current only, 
Please let me know as a reference value?
Best regards
Hayashi
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TPS53659: TPS53659 I2C built-in glitch filtering by default on I2C input pin?

October 25, 2018, 11:20 pm
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Part Number:TPS53659

Hi Sir,

TPS53679 also having a comparator with hysteresis to meet the electrical specs in the SMBus or not?

Hugo

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BQ24133: OPERATION LOGIC

October 25, 2018, 11:49 pm
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Part Number:BQ24133

Hello again,

Here I have a problem. When calculating Duty Cycle, I gained (13/12) 1.083 which is greater than 1. For I Cin Calculation there is square root of a negative figure.

How should I proceed? 

Is it normal to obtain D greater than 1?

Any help will be appreciated.

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BQ24232: Charging is suspended due to a battery pack temperature fault,

October 26, 2018, 12:13 am
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Part Number:BQ24232

Hello 

         Customer setting around 60°C on TS pin to monitor battery pack temperature. While over 60°C battery pack temperature, customer indeed find charging suspend. But they would like to know have any pins to monitor status while battery pack over-temperature protection happen and charging suspend now. They can not know status while battery pack over-temperature.Thank you. 

BR

Patrick

 

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BQ25505: On operation when VSTOR voltage is low

October 26, 2018, 12:22 am
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Part Number:BQ25505

Hi teams,

When the BQ25505 charge the capacitor (1F) from empty, the VSTOR was gradually increases.
Perhaps  as the timing of capacitor charged, it became a square wave of about 8 Hz.
As for this phenomenon, I think that it is contents not described in the datasheet, but is this phenomenon always happen?
Or it is a state before VBAT_OK and so does not support itPlease kindly advise.
Best regards
Hayashi(Please visit the site to view this file)(Please visit the site to view this file)
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TPSM846C23: The variation of Vout

October 26, 2018, 12:38 am
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Part Number:TPSM846C23

Hi,

We got a question from the customer about TPSM846C23.
Could you help us?

[Question]
How much is the variation of Vout at below conditions?

 Rset=10k
 Tj=-40~125C

We assume we should consider "Setpoint voltage tolerance" and "Temperature variation", so it is +/-2.5%. Is this our understanding correct?

Best Regards,
tateo

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How can host(MCU) control device enter into shutdown mode with command?

October 26, 2018, 12:43 am
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Hi,

      As I known,device(bq20z75) can enter into shutdown mode when write 0x0010 in Manufacturer Access.

but ,how can host(MCU) control device enter into shutdown mode with command?   we can read FullChargeCapacity(0x10)  register with SBS Cmd,but how can access the Shutdown(0x0010)?

Thanks!

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TPS23861: Power on sequence

October 26, 2018, 12:44 am
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Part Number:TPS23861

Hello

             For TPS23861 power consideration, VVPWR rise to 18.5V before VDD 3.3V tthen rise RESET_N to 0.9V, right? if VDD 3.3V rise before VVPWR up to 18.5V, has any effect for this power sequence? Thank you. 

BR

Patrick 

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UCC28083: ESD : Human body model (HBM) rating

October 26, 2018, 1:03 am
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Part Number:UCC28083

Team,

Do we have the HBM (Human body model) rating for the device?
What information are available regarding the ESD protection/tolerance/testing of the device?

Thanks in advance,

Anthony

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BQ27426: What's recommend range of Rsense value?

October 26, 2018, 1:05 am
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Part Number:BQ27426

Hi,

What's recommend range of Rsense value? It recommend 10mohm in datasheet. I want to change 5mohm. Is it suitable for SRN-SRP? Meanwhile, would you provide recommend value for "Input voltage range of SRN-SRP"?

Below value looks like "Absolute value."

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BQ76PL455A: BQ76PL455A Measure voltage?

October 26, 2018, 1:12 am
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Part Number:BQ76PL455A

I want to  Measure  16 series Bat  Voltage,BQ76PL455A can  Measure  Each battery voltage? if not,Please help to recommend PN? Tks!

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TINA /香料/ TPS54240： the TRACKING function

October 26, 2018, 1:26 am
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Part Number:TPS54240

Tool/software:TINA-TI or Spice Models

Hello

I download a file to simulate, but the SS/TR can't be adjusted by an external voltage.
The TRACKING function doesn't work.

Both of TPS54240& TPS54260 are the same result.

Andy

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TPS62088: leakeage when Vin lower than Vuvlo

October 26, 2018, 1:42 am
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Part Number:TPS62088

When Vin is lower than Vuvlo we see a leakage to gnd, the leakage is in the range of mA and increase with temperature. We are not using the device but it is an issue that it consumes power since it drains the battery.Is this a known issue?

BR

Martin

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EMB1428Q: how can i know the EVM is balancing

October 26, 2018, 1:46 am
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Part Number:EMB1428Q

Hi，dear

I‘m using 1402EVM to test battery active balance function.The 1402EVM board is powered on and starts working,  LED  D15  lights up.

I use a other MCU connect to EVM, not TMS570. I am writing my own code with reference to the code of TMS570. and I set a fix channel to balance.

The Phenomenon is LED D4  is blinking，with subtle sounds.

So, I want to know how can i know the channel is balancing ？Another question，how to connect the J2 connector with MCU's SPI on the EVM?

regards.

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