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LM5060-Q1: How to implement it the LM5060 controlled 4 MOSFETs ? Is there reference design?

October 31, 2019, 9:52 pm
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Part Number: LM5060-Q1

Hi,

Our condition is in a high current output application, the LM5060 controlled 4 MOSFETs are parallel in use that the package is TO263.

I just can found the example with one MOSFET in LM5060's EVM, but how to do it in MOSFETs parallel condition for layout placement?

Or if there is reference design for LM5060-Q1 with using "Parallel MOSFETs" that could be great for us.

Besides, the MOSFETs font end are current sening shunt resistors(4pcs x 2512 size), what placement is good for this structure? Or using only one shunt resistor is better?

Appreciate for your help.


Thanks much,

Lewis

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BQ24725A: BMS

October 31, 2019, 10:01 pm
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Part Number: BQ24725A

Hi,

  • The system load requires 7A and the battery requires 6A to charge. If a 13A adapter is connected, can both battery charging and system load be supported at the same time using external BATFET and input ACFET/RBFET? 
  • Is there any way to know the SOC of the battery using BQ24725A?

Thank you

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TPS40200: Could you tell me how to calculate rising time of output voltage?

October 31, 2019, 10:42 pm
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Part Number: TPS40200

 Hello guys,

 One of my customers is considering using TPS40200 for their next products.

 They have a few questions as the follows. Could you please tell me your reply?

 Q1. In Figure33 on page 25 of TPS40200 datasheet(SLUS659G), which range is correspond to tss calculated with equation (6) on page 17?

      Is the range from about 0.7V to about 1.4V? If the answer is yes, Figure 33 waveform has a little error from it. Do you know the reason of the error? 

 Q2. Do you have any equation which can calculate VOUT rising time (the time from voltage rising point to the target voltage stable point)?   

      In Figure 33, it seems that the rising time is about 800us.

 Your reply would be much appreciated,.

 Best regards,

 Kazuya.

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LLC resonant converter

October 31, 2019, 10:47 pm
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Hi all,

The diode bridge rectifier efficiency is around 81 %. But in case of a LLC converter the secondary is connected to a diode bridge rectifier. But still the efficiency is more than 95 %. How it is possible?

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BUF22821: What's difference between BUF22821 and BUF20800 ?

October 31, 2019, 10:58 pm
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Part Number: BUF22821

Hello,

What's difference between BUF20800 and BUF22821 ? including software and hardware, could I use BUF22821 pin to pin replaced BUF20800 ? I find BUF22821 just have additional 2 channel than BUF20800,  the difference is BUF20800's PIN3,4,35,36 is NC,while BUF22821 is the gamma buffer.

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TPS92518: Pattern Sample Code for RTOS or Linux

October 31, 2019, 10:58 pm
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Part Number: TPS92518

Hi Expert,

Do you have any pattern sample code for RTOS or Linux can share?

Thanks.

Allan

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TPS2557: IEC62368-1 certification

October 31, 2019, 11:27 pm
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Part Number: TPS2557

Hi,

Customer want to have IEC62368 certification for TPS2557DRBR, please help to provide its certification letter and report if it was done.

Thanks and Best regards,

Tiger

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TPS61196: audiable noise

October 31, 2019, 11:32 pm
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Part Number: TPS61196

Hi Sean,

Do you have any idea with last post：when current is lower than 60mA,3ch, the boost converter seems into hipcup mode /skip frequency mode, caused audiable noise. when I inreasing the totally current to 60mA,5ch, the SW frequency is recovery and no sound.

Now another case also used TPS61196, 12V input voltage, 4p/11s LEDs,output voltage about 36V. also could hear sound, so I am doubt that if TPS61196 is suitable for low current demand ?  

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BQ25703A: BQ25703a default settings that surely runs ?

October 31, 2019, 11:25 pm
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Part Number: BQ25703A

Hi, TI tech support team, everyone,

I am using BQ25703A for charging the backup battery of my device.

The main power source will charge the battery to full and stop charging.

When the main power is lost, it switches to this backup battery.

Is there any "default settings" for BQ25703A to use ?

By "default", I mean it definitely works. Current I could read and write 25703A's registers via I2C

(using Linux), and got the response from 25703A, shown as follows.

 

However, when I checked out ADC registers, all values are 0. It supposes that if my

settings are correct, ADC registers will have values (and changing over time).

 

I don't know I missed something. Can you please give me some heads-up ?

Thank you.

Alan

 

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TPS7A66-Q1: smallest power consumption LDO

November 1, 2019, 12:03 am
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Part Number: TPS7A66-Q1

hi Team,

customer using LDO for NB battery pack project.

it's looking for small package and low consumption as much as possible.

is there a device with less power consumption to the "TPS7A66-Q1"

the Vin is (3 series cell pack) ~15V

output 3.3V 5V and current 100mA

Thanks very much for the help

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LM5116: Over temperature protection about.

November 1, 2019, 12:29 am
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Part Number: LM5116

Hi,

I am using the LM5116 for buck converter. I need to protect the circuit from temperature. The IC has protection but it doesn't matter to my application. 

* I will use NTC. Using the NPN transistor with serial diode, i will keep the UVLO between 0.4-1.2V. The system will then enter standby mode. I'm thinking of working with VCC on IC. My question is;  Can I use this circuit smoothly with VCC?

Do you have any other suggestions for this (with NTC)?

* I'm thinking of using this protection circuit for LM5122(for boost). There is an overvoltage protection circuit for the LM5122. I want to apply both. (OTP and OVP)

Is it correct to manipulate UVLO.

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TPS23881: Port Mosfet parameter selection guide in the datasheet

November 1, 2019, 12:36 am
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Part Number: TPS23881

Hello,

As shown below, the datasheet notes the Qpn should follow the Rds_on, Qg and Ciss guide.

Why? Do we must follow them?

Is there any documents to show the reasons?

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BQ40Z80: How to connect to PDSG PFET when pin20 is used as PDSG

November 1, 2019, 1:19 am
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Part Number: BQ40Z80

In the design, I want to use pin20 as PDSG function, and TRM(SLUUBT5A) is described as follows in Chapter 11.1:

"The exception is if the PDSG functionality is selected using the LEDCNTLA pin(RL0, pin20),which has an internal high-voltage drive capability and can drive the PFET gate directly(in which case the polarity of the pin signal changes)."

Does this mean that pin20 is directly connected to the grid of PDSG PFET as shown in the figure below?

If what I said is wrong, please tell me the correct connection method, thank you!

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TPS92682-Q1: Design procedure for Buck-Boost power supply

November 1, 2019, 1:19 am
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Part Number: TPS92682-Q1

I'm looking at a design using the TPS92682-Q1 so for all my designs I generate a spreadsheet.to calculate the values.

As part of this I usually put a know design into my calculations to ensure that my spreadsheet results are working.

I've gone through 8.4.4 of the TPS92682-Q1 Datasheet that describes a Buck-Boost Design Procedure to use this to check my spreadsheet.

When I've got to 8.4.4.4 Inductor selection the value given for L is 23.4 uH 

I'm trying to get my spreadsheet to match this but even changing the values to VO , VIN & PO(BDRY) I can't get the values to match.

Is there stored anywhere the original values used for the equations in other examples I've seen on TI datasheets these values are given.

or does anyone have a spreadsheet that will calculate the values for a TPS92682-Q1 ?

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BQ24725A: No battery circuit

November 1, 2019, 1:20 am
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Part Number: BQ24725A

Hi Sir,

Customer is doing a second generation product without battery, but they would like to share the same circuit as previous generation. In previous generation, they use BQ24725A on their system with a Battery.

The question is that customer would like to know what circuit they could remove if there is no Battery installed?

Thanks,

Patrick 

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TPS23861: TPS23861 no output

November 1, 2019, 1:34 am
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Part Number: TPS23861

Dear all:

The motherboard was normal at first, and it took a while to find the POE interface was abnormal.TPS23861 no output.

Use the voltmeter to touch the positive and negative poles of the power supply pin of the PSE device respectively. The voltage is displayed as 0 volts.It seems that there should be no detection.

Originally thought to be a single board problem, now I found more than one.

Now I want to know what went wrong with the chip and what is the cause of the problem.

Thank!

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TPS7B7702-Q1: Sense pin connection when not used

November 1, 2019, 1:40 am
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Part Number: TPS7B7702-Q1

Hi,  Team:

Can you help to check if there is risk to connect the Sense2 pin to GND with 10Kohm resistor when not used? Customer test and find there is oscillation in the pin with scope measure. 

Besides, customer find one system fail. Measure and find VCC to GND resistor is 0ohm and EN2 to GND resistor is about 40ohm. 

Need your help to check and give some advise.(Please visit the site to view this file)

Schematic and waveform showed in attached file.

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In I2C communication, bq27750 can not be written

November 1, 2019, 1:49 am
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when i use bq27750,i can read data from data flash.but i can not write data to dataflash.

my writting process is as follow:

W : 0xAA + Write CMD + REG ADDR + datablock

W：0xAA + 0x3E + 0x63 + 0x45 + 0x30 + 0x11

0xAA is write address(donot care)

0x3E:Recommend by datasheet

0x63&0x45: 0x4563,it is address of design capacity reg

0x30&0x11: 0x1130 :designed value of capacity,4400mAh.

so ,what is the problem in my process?

and , what is the right writting process?

hope your reply

sincerely 

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BQ76200: bq76200, External relay

November 1, 2019, 1:51 am
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Part Number: BQ76200

I am working on BMS for LFP batteries, and I would like to use extrenal power relay for commutation battery and load. As I use bq76200 to control charge/discharge, I would like to know, if it is possible to control external relay (for example with 12V coil voltage) using bq76200?

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TPS56221: Soft start

November 1, 2019, 1:57 am
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Part Number: TPS56221

Hi TI,

Is there a maximum capacitance that can be implemented on the SS pin? The datasheet shows only typical time.

Soft-start ramp time means the time output voltage rise 0 to Vout. right?

How do I calculate the start time when the output voltage is not discharged and the start time is triggered?

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