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UCC28950: Fsw setting

November 7, 2019, 1:05 am
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Part Number: UCC28950

I'm involved in a 10kW PSFB ZVS design, I saw that UCC28950 can drive both, the primary side switch and also the device on the synchronous rectifier. I used the the SLUC222D for preliminary estimation of the system and I can set the Lout frequency switching with value below the minimum value indicated in the datasheet, I mean, in the datasheet is stated that the recommended Fsw shall be in the range 50kHz -1MHz but in the tool I setted 30kHz and no warning has been rised. Does it mean that I can use also Fsw lower than the 50kHz? If yes what would be the behaviour of the device at 30kHz?.

Thanks for the support

Pietro Ciammaichella

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TPS40061: Un-encrypted model / library

November 7, 2019, 1:10 am
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Part Number: TPS40061

We are using TPS40061PWP, in one of our existing designs. We would like to carry the simulations on this controller.

When I searched I could only find the encrypted models. We would like have the un-encrypted model / library of the TPS40061PWP. Can somebody help me on this.

Thanks

Ravikumar  

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LM5050-1-Q1: LM5050-1Q1

November 7, 2019, 1:24 am
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Part Number: LM5050-1-Q1

Hi Team,

I would like to protect my electronic board form reverse polarity using a reverse polarity protection circuit.

The supply is 12V or 24V. Load current is about 35A (current absorbed by DC/DC Boost converter).

For this high-current, I evaluated LM5050-1-Q1 but the selection of the N-channel Mosfet selection is very critical.

For my application I must comply with ISO7637-2 and ISO16950-2 and it's important to fix the Vdss Mosfet:80V-100V

As reported in the datashet, the requirement is:

  22mV/I_load <Rds(on)< 100mV/I_load -> 0,62mOhm <Rds(on) < 2.8mOhm

In particuar, at 22mV the N-Mosfet with Rds(on) so low, is very difficult to find and in any case, it would be very expensive.
and so I Would be inclined to use 2 N-Channel Mosfet.


Each mosfet will then be crossed by about 18A -> 1.2mOhm <Rds(on)> 5.5mOhm

It's correct to choose a Mosfet with Rds(on)>1.2mOhm?

For example, I could choose also 4.5Ohm (always less than 5.5mOhm)  or 100mV/I-load  is a parametr only as guide-line? I dont' undestand the meaning of upper end of the range...

My further doubt is: f you also found me the  Mosfet with these characteristics, IC LM5050-1Q1  has tha ability to drive 2 Mosfet?

I think that LM74700 is more suitable (gate drive is powerful).It's correct?

As one of the requirements is to pass the test ISO7637-2 and ISO16950-2 it's correct to use same circuitery of evaluation TIDA-00992 for LM74700? Naturally means TVS and capacitors...

The datashhet of LM74700 provieds 2 different solutions for 12V and 24V supply instead evalution TIDA-00992 provieds only one solution
for which I have the doubt.

Please, let me Know.

Thanks.

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BQ27621-G1: About Data Flash setting Battery Charge Voltage at 4.1 V

November 7, 2019, 1:30 am
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Part Number: BQ27621-G1

Hi  

Our Customer using BQ27621G1 , but their Battery company suggested  battery Charge Voltage for 4.1V.

This battery typical Charge Voltage is 4.2V , but customer want to use Charge Voltage 4.1V. 

I think their reason is   " long life "  

 Yes ,  We know BQ27621G1 Chemical ID fix for these 3 type  4.2V / 4.3V / 4.35V

[ Question ]

  Which change Setting Resister when battery change voltage 4.1 ?? 

    * This mean we want to know , Dose we need which resister change at  battery 4.1V ?  

  I think, we need change  " Taper Voltage " setting with Chemi ID 4.2V. 

  is this correct ??    

   

Regard

March Jasper  ( Japan Disty  Sugimoto ) 

  

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BQ51052B: Wireless Power Transmitter solution

November 7, 2019, 1:33 am
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Part Number: BQ51052B

Dear experts,

My customer is developing a wireless charger. Now they know the receiver is bq5105xB, and they want to select a compatible transmitter IC that can support charge to multi-receiver (such as 3) and  5-10W power delivery?

Could you help to share some suggestions? Thanks.

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TPS791-Q1: Ripple Rejection of TPS79101DBVRQ1

November 7, 2019, 1:47 am
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Part Number: TPS791-Q1

Hi,

In the datasheet of TPS791-Q1, the ripple rejection vs frequency charts are given for TPS79133 and TPS79118, not for TPS79101. I would like to have the graph as it is significant from my point of view.

Thank you.

Regards,

Naveen Sankaran.

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BQ25619EVM: Is there a program case program for BQ25619?Please provide. Thanks

November 7, 2019, 1:55 am
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Part Number: BQ25619EVM

Is there a program case program for BQ25619?Please provide. Thanks

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Output capacitor selection

November 7, 2019, 2:17 am
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Hi all,

How is the filter capacitor chosen for output voltage of the DC - DC converter used for automotive applications?

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TPS53353: TPS53353 PGOOD pin cannot be high-impedance when output is good

November 7, 2019, 3:05 am
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Part Number: TPS53353

Hi team,

Our customer meet some problem with TPS53353 PGOOD pin. Please refer to the detail information below.

1. Our customer do the test with 4 pcs tps53353, only 1 pcs works good, other 3 pcs all meet the issue

2. PGOOD pin is pull up to VREG through 100kohm resistor, VREG is 5V when the output of TPS53353 reaches 3.3V, but PGOOD pin is not high when Vout=3.3V

2. We change the 100kohm pull up resistor to 100ohm, PGOOD pin is 1.6V now.

3. We remove the pull up resistor R1436, and also the 0ohm R1453 connected to LED string, to make PGOOD pin floating, and we test the impedance to ground of PGOOD pin, it's about 800k when the device is not power on, and it decrease to 40ohm after power on.

We also do the test with the good one, the impedance is about 800k after power on, so the PGOOD pin can be pulled high.

Could you please give some comments on what may be the issue cause?

Thanks.

Best Regards,

Livia Liu

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TPS650861: LDO output capacitance limit

November 7, 2019, 3:28 am
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Part Number: TPS650861

Hi,

I wanted to ask about the capacitance limit on LDOA1, A2, A3 outputs.

Is 10uF really the top capacitance we can put on the output?

I want to connect LDOA1 output to 2 loads and I want 10uF at both of their inputs. Plus 4.7uF at LDOA1 output, so that gives about 25uF in total. Will that be OK?

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Current monitoring in battery charging system

November 7, 2019, 4:09 am
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I am looking for circuits used to measure or monitor the current charging of a battery (Li-Ion or NiMH), microchip has proposed the circuit of the following link

ww1.microchip.com/downloads/en/DeviceDoc/51641a.pdf

My concerne is about the circuit given in page 16/30 composed of C12, C15 R16 and R18, how does this circuit work to measure the charging current of the battery  and What is the contribution of R16, C12 and R18

 

 

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Boost for using with a battery Li-MnO2 (3V) and a NB-IoT module.

November 7, 2019, 4:16 am
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Hi everyone,

I am trying to find a boost for my application. I have a battery Li-MnO2 (3V@ Max continuous current of 500mA) connected directly to a NB-IoT module. The problem is the peak current with the NB-IoT module, it makes a drop off voltage below 2.1Volts and the devices switch off. The power supply of my NB-IoT module has to be > 2.1Volts.

So I need a Boost with  4.0 > Vinput > 1.5V. When the Vin < (2.7 - 2.5) Volts (i.e.) The Vout = (2.7-2.5) Volts and when Vin > (2.7-2.5) Volts, Vout = Vin.

The NB-IoT module has an energy consumption of 3.5uA in deep sleep mode, so the boost has to be prepared for ultra-low power energy.

I've found this part number TPS610995, but it seems to be there are some issues with it, so Does anyone any other suggestion?

Best regards.

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BQ25713EVM-017: Automatic loading EVM registers with BQStudio possible?

November 7, 2019, 4:28 am
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Part Number: BQ25713EVM-017

I have the EVM connected to the I2C port of EV2400 and controlled by BQStudio v. 1.3.92 Build 3.

Is there a way to load the registers in the EVM's charging IC other than manually one by one? I tried the "Load Registers" button but it has no effect. I am in the process of learning the battery pack characteristics by "manually" charging it and every time I have to navigate through the registers menus pointing and clicking (e.g. picking the charging voltage and setting the ADC channels I want to monitor) and it is a PITA.

TIA.

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CCS/BQ27542-G1: Need BQ27542 BQ.FS or DQ.FS Files

November 7, 2019, 4:39 am
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Tool/software: Code Composer Studio

Hello TI, 
              we need BQ.FS or DQ.FS for BQ27542 Configuration please try to send ASAP, we already spend too much time on BQ studio 

we need to test functionality of BQ27542 by flashing configuration file by using arduino board  

please send BQ.FS or DQ.FS file for BQ27542 

Email ID- rahul.s@phynart.com

Thanks,

Rahul Surawase

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BQ24005: charge done status

November 7, 2019, 4:49 am
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Part Number: BQ24005

Hello,

The STAT2 (green LED) turns on every time when the DC adapter is connected to the input. The STAT truth table shows that the green LED should turn on only at "charge done". The APF/THERM has the exact same resistor dividers as on the EVM. The charging and end of charge is normal. 

The charger is connected to a host microcontroller and it is not able to distinguish the adapter connected state to the charge done state since the STAT2 stays on in both cases.

what am I missing?

Thanks,

Gaurav

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MC33063A: write simulation but bad signals

November 7, 2019, 5:27 am
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Part Number: MC33063A

Hello,

I simulatet a stepup converter.

I have already set up the circuit and received metrologically similar / same signals

But I think there is something going wrong because the signals look bad.

At first the simulation shematic

Now the meassured signals:

I cant find there a fix frequenzy, more some swinging signals.

In application normaly we have constant current of 50 to 100mA and some Peak of 21A für 1,2µs when the IGBTs are switching. They swithing whith 4, 8 or 16kHz.

for calculation:

worst case at 16kHz 62,5µs/1,2µs * 21A = ~400mA

400 +50 mA =450mA

whith an output of 16V, an input of 12V and a minimal sw-freq. 55kHz I've calculate:

Ton/Toff0,60 
Ton+Toff1,82E-05s
Toff1,13E-05s
Ton6,83E-06s
Ct2,73E-10F
Ipk1,44A
Rsc0,208Ω
Lmin4,74E-05H
Cout2,77E-04F

So I hope you can helb me.

If you would like to give me your mail adress I can send the Simulation-Model

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BQ20Z655-R1: bq evaluation software (Instantaneous jump in the remaining capacity & relative state of charge is 100% due to the remaining capacity value jump and non zero charging current flow)

November 7, 2019, 5:56 am
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Part Number: BQ20Z655-R1

While charging( using BQ24171 battery charger) the battery( 3S1P) it is observed that in bq evaluation software(device BQ20Z655-R1)  remaining capacity 3711mAh got jumped to 4011mAh (check video), why is this sudden jump ppening? which results in jump in relative state of charge as well from 93% to 100%. 

Secondly while relative state of charge is 100% why there is still non zero charging current(check video)?.

(Please visit the site to view this video)

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TLV62130: Current consumption at no load

November 7, 2019, 5:58 am
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Part Number: TLV62130

Hello experts,
I got question for current consumption at no load from customer.
With TLV62130EVM-505, customer set 12Vin and 5Vout.
At no load, input side current is above 10mA. It looks not only Iq.
Do you have any idea for the phenomenon? 
Also, I heard, TPS562210 (D-CAP2 Control) at no load, input side current is almost Iq.
Is there any possibility that DCS-Control cause this phenomenon?
Customer wants to implement very low power consumption at no load.
Thanks and best regards,
Ryo Akashi
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TLV61048: The output current of TLV61048

November 7, 2019, 4:32 am
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Part Number: TLV61048

Can Input=5V/5A  achieve output=12V in TLV61048 ?If can,what is the maxium output current?If the efficiency is 90%, then I_out=5*5*0.9/12=1.875A?Thanks!

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BQ79606A-Q1: Configuring cell balancing timer in miliseconds

November 7, 2019, 6:31 am
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Part Number: BQ79606A-Q1

Hello,

The datasheet of BQ79606 states that the min value for cell balancing timer is 1 second. My question is that, can we reduce the balancing time period to less than 1sec for example 10 miliseconds? I have gone through the datasheet for BQ79606-Q1 , as per it, the min configurable value for timer is 1 second.

Is there any other approach available for my requirement? 

Thanks in advance.

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