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LMR23630: capacitor selection for Cin

May 13, 2019, 4:18 am
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Part Number:LMR23630

Hi team,

According to the datasheet, 4.7uF~10uF capacitor is recommended for Cin. The customer is using this device at 24Vin in several applications, but the capacitor they are currently using for the Cin will be NRND, and they will have no capacitors which is just met to above requirement in their common capacitors. In that case, could you please provide the answer for the below?

1. When OS-CON + Ceramic capacitor(small size) are used for Cin at 24Vin, what is the worst capacitance the customer should keep?

2. Can Aluminum electrolytic capacitor + Ceramic capacitor(small capacitance) be used for the Cin in above use-case?

Thanks & Best regards,

Jun 

 

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TPS5430: capacitor selection for Cin

May 13, 2019, 4:20 am
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Part Number:TPS5430

Hi team,

According to the datasheet, 4.7uF~10uF capacitor is recommended for Cin. The customer is using this device at 24Vin in several applications, but the capacitor they are currently using for the Cin will be NRND, and they will have no capacitors which is just met to above requirement in their common capacitors. In that case, could you please provide the answer for the below?

1. When OS-CON + Ceramic capacitor(small size) are used for Cin at 24Vin, what is the worst capacitance the customer should keep?

2. Can Aluminum electrolytic capacitor + Ceramic capacitor(small capacitance) be used for the Cin in above use-case?

Thanks & Best regards,

Jun 

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TPS23752: IBIS Model

May 13, 2019, 4:26 am
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Part Number:TPS23752

Hi,

Need IBIS Model for TPS23752, to check for EMC simulation. Please let me know which model suits for my requirement. 

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Question of TPS389x

May 13, 2019, 4:31 am
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We have a question about TPS389x.

http://www.ti.com/lit/ds/symlink/tps3896.pdf

About V(POR) in datasheet p.6,

(1) The lowest supply voltage (VCC) at which output is active (SENSE_OUT is low, SENSE_OUT is high); tr (VCC) > 15 µs/V. Below V(POR), the output cannot be determined.

We have a question about the above.

Output voltage could be equal to VCC when the situation is in the above description.

For example, when VCC is 0.7V, Vout is 0.7V.

Is this understanding correct?

Best regards,

Takahiro Nishizawa

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BQ27Z561: Question about the FCC curve in the datasheet

May 13, 2019, 4:38 am
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Part Number:BQ27Z561

Hi team,

My customer is evaluating BQ27Z561. They have a question about below curve in our datasheet.

How to understand the third curve 'true_FCC' in below picture? From my understanding, the capacity should gradually drop along with the current output. But why it is a stepping waveform in below picture and sometimes steps up and sometimes steps down?

By the way, customer also has below question:

1. How does the gauge determine if there is a valid battery connected?

2. Can the gauge  know how many cycles has the battery charged and discharged? If it can, which parameter does it use to calculate the cycle? 

Thanks.

Best regards,

Wayne

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BQ25713: Startup current waveform

May 13, 2019, 4:38 am
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Part Number:BQ25713

Hello,

Do you have a waveform of what the startup current from adapter input to system output look like?
I think that an inrush current can be limited by input current sense on ACP-ACN and want to know how immediate it can work after releasing HIZ condition.

Thanks in advance.
S.Sawamoto

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TPS61201: TPS61201 can't output 3.3V when input>0.3V.

May 13, 2019, 4:40 am
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Part Number:TPS61201

My project is harvesting the radio frequency energy and store it in a capacitor. After the capacitor is a TPS61201.  According to the datasheet, the input range is 0.3-5V, when I using a 1.5V 3A battery to test the booster, the output is 0.25V only!!  Here is my circuit. 

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UCC21732-Q1: Availability

May 13, 2019, 4:48 am
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Part Number:UCC21732-Q1

It seems that this is ideal part for our multiphase buck converter. I have already ordered samples and we would like to start production in September. We would need 1000pcs for initial series.

I would appreciate private contact about availability.

Best regards, Janko

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TPS717: adjustable output voltage calculation

May 13, 2019, 4:55 am
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Part Number:TPS717

HI Team, this does not look right section 8.2.1.2 :-   the denominator will be negative?

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TPS54228: regarding Vreg UVLO and hysteresis

May 13, 2019, 5:29 am
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Part Number:TPS54228

Hi, Team.

could i confirm my understanding correct what i've been asked by Customer?

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LMZ14202EXT: Lead Finish

May 13, 2019, 5:31 am
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Part Number:LMZ14202EXT

Hello, I wanted to clarify some information provided in the page of this component.

It says that the Lead / Ball finish is CU SN, does this refer to a copper / tin alloy? Or does it stand for pure tin (100%Sn)?

Thank you and best regards

Gabriel

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TPS53315: Datasheet maximum rating check

May 13, 2019, 5:37 am
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Part Number:TPS53315

Hi Team,

Would you please help to check the output voltage of LL? is it correct?

It looks different with TPS53355.

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Need +15V/1A Non-Isolated AC/DC Converter for Metering applications

May 13, 2019, 5:46 am
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Hi,

Can anyone suggest +15V/1A Non-Isolated AC/DC Converter or SMPS for metering application ? Please let us know asap

Regards,
Kamesh Lakhwani

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BQ24600: BQ24600/bq2970: Charging does not start when the battery is deeply discharged

May 13, 2019, 5:47 am
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TPS54260: TPS54260 thermal resistor

May 13, 2019, 6:29 am
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Part Number:TPS54260

Hi,

could you help to confirm Why RθJC(top) bigger than RθJA in datasheet of TPS54260? 

Thanks.

Mark Chen

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UCC28780: Can UCC28780 design a 300W charger?

May 13, 2019, 6:32 am
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Part Number:UCC28780

My customer wants to design a 300W charger with UCC28780, input 100Vac-240Vac, no PFC, output 24V@300W, or 48V@300W. Can UCC28780 do that? What are the drawbacks if it can be done? What are the recommendations for the corresponding synchronous rectification chip and upper tube driver chip? Do you have a complete design? Thank you.

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BQ34110: Facing problem in RC and SOC during Discharge Cycle

May 13, 2019, 6:47 am
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Part Number:BQ34110

Hi,

We are facing issue in BQ34110 during Discharge mode with Load. The test procedure we followed is as follows,

    Charged the battery with the constant charging current. Remaining capacity(RC) is increasing from 0 to 6000mAH and State of Charge(SOC) is increased from 0 to 100. And the FC bit is setting when RC is equal to FCC. It seems fine for us.

But the main problem we are facing is in discharge mode. 

I will stop charging and without load RC and SOC is giving the correct value. But once I switch on the load (Constant Discharge Current 3.5A) FD bit is setting, RC is drastically decreasing to below 200mAH and SOC to 3% and then to 0%. So Discharging is going wrong somewhere.

Please suggest.

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BQ34Z100-G1: BQ34Z100-G1 after MCU shutdown then reset, SOC change 70% to 100%

May 13, 2019, 6:58 am
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Part Number:BQ34Z100-G1

Dear colleague,

A customer said after MCU shutdown then power up, they find SOC changed from 70% to 100%.

Below is code, do you have any suggestions to check the issue?

   Delay_ms_0_5(2000); 

   BQ_readBlock(0x63,&RxData[0],2);

   if((RxData[0] &0x06)!= 0x06)

   {

         Delay_ms_0_5(200); 

         BQ_Write_WORD(0,0x21,0); //ITENABLE

   }

       Delay_ms_0_5(1000); 

Best Regards,

Rock Su

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BQ76940: temperature compensation to improve cell voltage accuracy

May 13, 2019, 7:08 am
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Part Number:BQ76940

Dear TI experts,

Our company is using bq76940. But the ADC cell voltage error under –40°C to 85°C is not low enough for us. To imrpve the accuracy, I have some questions. Could you help me to solve it?

Q1: What’s the characteristics of cell voltage ADC monitoring error at different temperature ?

Q2: How’s the consistency of each pcs at different temperature, and is it possible for us to compensate the impact of temperature by software programming?

Thanks a lot.

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WEBENCH® Tools/TPS54360: Capacitors parameters in Webench design

May 13, 2019, 7:18 am
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Part Number:TPS54360

Tool/software: WEBENCH® Design Tools

Hi team,

I want to use Webench for TPS54360 power design. When I chose capacitors, I met some questions. You can see the Qty of Cin is 2 in below schematic, does that mean there are two capacitors in paralell as input capacitors and each of them is 10uF? Another question is "total derated cap", I see this value is different for different capacitor, sometimes it is equal to capacitor's value(Ccomp2), sometimes it is lower than capacitor's value(Cboot), as below figure shown. So what is the parameter stand for? And how it influence my design? thanks very much.


Sophia Yao

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