Part Number:TPS54240
Hi all,
My customer need MDS data from IMDS system about TPS54240DGQR and LP2951ACM-3.3. They have a customer ID 74494. Can we enter their account# in IMDS system so they can get MDS data about the two devices? Thanks for your kindly help.
Somebody have similar issue in below link...
Best regards,
Gary Teng
Part Number:TPS65217
Hi
The customer intend to use TPS65217 under the following condition.
- Battery is absent
- AC is prioritized over USB
Question
1.
Could AC_EN and USB_EN be turned off automatically if the input absence is detected?
2.
Is it possible that the leak current from USB to AC pin could be flowed when AC_EN and USB_EN are 1? (AC and USB are shorted?)
The reason why they have second question is that they concern possibility of reset
could occur when power input is switched from AC to USB.
3.
Can we switch input from AC to USB without Vsys voltage droped?
BestRegards
Part Number:UCC28070A
Hello.
Thank you for the data of Mathcad calculator the other day.
I calculated using this.
Also, we designed the same specifications using WEBENCH.
As a result, it became a big difference design.
Choke coil value is about 10 times (MathCAD: 22 μH versus WEBENCH: 220 μH) There is a difference.
Also, the choke coil selected by WEBENCH has a very small rated current of 3.5 A is selected.
Actually I think that it is necessary to have a peak of 30 A class.
Is it possible to send design data of WEBENCH and MathCAD and see which design is better?
Please let me know your email address if possible.
Thank you.
Hello All ,
Currently looking into a 2kV/3kW output , capacitor charger design (400VDC input) , can anyone recommend a t.i solution (full bridge ideally).
Best regards
Mark
Part Number:TPS5410
Hi Guys , I have use TPS5410-EVM board , and that is good Perfect waveform and good ripple .
But i designe the new circuit for tps5410 which cap and resistor is choice by myself.
then the circuit is like this.
Now i have problem is that if RL is low value which near 0~10 ohm then make high output ripple and two oscillator like picture 
which is almost 1.8MHZ frequency, i don't want this. how can i eliminate this frequency , i only need 500khz freq.
and another question is when i use high ohm which near 330ohm that the osillator is not build.
i use the tps5410evm and i find the high or low res is not effect the output frequency.
so why did the this oscillator build ? please help me thx all guys
Part Number:BQ76940
Tool/software: Code Composer Studio
As we used the BQ76940,
When Reading the data in the SYS_STAT register, the data is 0x20,
That mean the 5th bit of the SYS_STAT register "DEVICE_XREADY" is 1, and this is meaning that an error has occurred inside the chip. The data register reading value that causes the battery voltage and current is 0. and can't be reset
Please help analyze it.
we have checked the voltage of battery is no problem.
Hi team
On the product page of BQ4050 it is said that max battery capacity is 29 Ah. But I can't find any notes about it in the datasheet.
I need to gauge a battery pack with capacity about 40 Ah, is BQ4050 can do that?
If 29 Ah is maximal capacitance, is there any scaling method?
Thank you.
Part Number:BQ24610
Hello,
I am designing a circuit for charging a 6-cell lithium polymer battery. The maximum voltage of this battery is about 25.2V, so I had thought to use a 28V AC/DC adapter. Because 28V is the maximum voltage specified in the recommended operating conditions, would there be risk of rupture? Would your life time be shortened as you are working at the maximum voltage allowed? Thank you.
Part Number:UCC28070
Hi, I have some questions for the "Current Sense Offset and PWM Ramp" which is mentioned in UCC28070 datasheet 8.2.2.8. Could you please help to answer them?
1, As the datasheet said, the purpose of this offset and ramp circuit is to add some offset at light load, when inductor current is in DCM. But i did not understand that, during PFC mosfet turned off period, UCC28070 will have current synthesizer to simulate the down slope current signal. That is say even there is current signal ringing when current is DCM, the chip should not be false triggered, because it is using the simulated current signal
2, could you please explain the figure 28 the false current ? In this figure, Rsa voltage has some offest, so it look like the waveform of offset and ramp circuit impelemented. But why when Mosfet is off, Rsa has no offset voltage? And if the ramp and offset circuit has already be implemented, why it is called "Discontinours current cause false current signal".
Thanks
Tao Wu
Part Number:TPS54620
Tool/software: WEBENCH® Design Tools
Hi,
I attach the simulation result of bode plot.
(Please visit the site to view this file)
When checking phase margin of bode plot and operating values, I got the following results.
・phase margin (bode plot sim): 62.724 deg
・phase margin (operating values): 27.005 deg
The values do not match, which value should I refer?
Best regards,
Yuto Sakai
Part Number:UCD3138
Tool/software: Code Composer Studio
PWM duty is very small, and EADC cannot sample the current transformer signal, resulting in a large duty ratio of one cycle. At this time, it is detected that the current transformer signal is large, and the duty calculated in the next cycle is 0 ?
Change the PID coef , it doesn't work .
How to realize low current detection regulation in PFC of UCD3138 ? Do you have some suggestions about it ?
Part Number:TPS62746
Hi,
Could you tell me about difference in efficiency by inductor?
I believe that figure 14 in the data sheet shows the difference in efficiency at each inductor.
Compared to MIPSZ2012D 2R2 (FDK) and 744 797 752 22 (Würth), Würth's inductor is inefficient, despite the low DCR.
Please tell me the reason for this result.
Best regrads,
Yuto Sakai
Dear sir / madam,
I want to make a mobile charger which should also read the battery level. Please suggest me appropriate the component.
Regards,
Manoj Hiwarkar
Part Number:LM34910
We have been into production for years with a board having LM34910 as one of the regulators. This is the main supply (logic circuits, 5V) of the board. The board has a microcontroller and a series of opto-sensors. The total power consumption (which is almost steady) is about 250mA. As the board was designed by a third party consultant at the time, we do not know the design parameters they used to. In the past a research on a similar board revealed that the values of the main inductor and the output capacitor were not the best solution and we believe this could be the case in this board as well. Nevertheless we have produced these boards in the past (around 15K) without a problem.
Here is the original circuit:
Recently out assembly manufacturer needed to add alternate components as the original parts specified were hard to find or were obsolete. It seems that after a point some of the boards (10 out off 1000) fail to communicate if we connect all or part of the load (opto-sensors), as a result of instantaneous under-voltage when the microcontroller tries to activate through a FET the LED power.
The parts replaced are D22 and L3.
| Part Designator | Original Component P/N | New Component P/N |
| L3 | Eaton/Bussman, UP2B-330-R | Coilcraft, DO3316T-333MLD |
| D22 | Vishay, VS-50WQ04FNTR-M3 | Diodes Inc, SBRT10U60D1-13 |
Our manufacturer says that the L3 tolerances are such that a higher inductance make the boards fail. As a proof he used a part with less inductance for L3 (27uH) and made these boards work.
However a colleague of mine, used the old D22 part instead (with the new 33uH inductor) and fixed his boards as well.
We have also noticed that heating the boards (after soldering task etc) makes the boards working until they cool down, where they start failing again.
Also if we start removing the loads (opto-sensors) one by one the boards become operational again.
It seems that the circuit is affected by the load (which is how we identified the problem, initially).
In order to check things myself, I measured the circuit with my scope at Pin 1 of the regulator on a good working board from the past (ie. original components). The regulator seems to work in continuous mode at 454KHz (as set by R96). However the pulse shows some ringing:
Good board, Output of Switcher.
I then instructed my colleague (I do not have direct access, this is in another location) to measure the same point on a failing board:
Bad board - not working, output switcher
It seems that the switcher works in a non-continuous mode (at about 60KHz).
Also note that after the pulse is finished (the small rectangular peak in the scope) the output voltage is 0. Later on a ringing happens and increase this level to 5V that remains till the next pulse.
It seems that the diode plays a critical role in this and the only obvious difference might be the Vf level of the diodes, as checking the plots seem to have 100mV difference.
Can you please explain how the diodes can affect the circuit and which parameters are critical?
As you may understand the boards are already manufactured and the best remedy is to change as few parts as possible. Our manufacturer proposes a slightly lower value inductor, but we have seen that the diode may also fix the issue. What is your recommendation?
Thanks in advance,
Ilias
Part Number:TPS25927
Hello,
According to "Figure 20. Accuracy vs Overload Current Limit" on page 10 of the datasheet the accuracy of the E-fuse varies strongly over the current limit span. In a simple estimation I receive following spread:
Min lim [A] | Target [A] | Max lim [A] |
0,70787 | 1 | 1,29387 |
0,80008 | 1,1 | 1,40208 |
0,8843 | 1,2 | 1,5183 |
0,9705 | 1,3 | 1,6325 |
1,07261 | 1,4 | 1,73061 |
1,16376 | 1,5 | 1,83976 |
1,2728 | 1,6 | 1,9308 |
1,3858 | 1,7 | 2,0178 |
1,48487 | 1,8 | 2,11887 |
1,58592 | 1,9 | 2,21792 |
1,68895 | 2 | 2,31495 |
1,79396 | 2,1 | 2,40996 |
1,90095 | 2,2 | 2,50295 |
1,98708 | 2,3 | 2,61708 |
Is the accuracy really this poor? During the limited testing I have done the E-fuse almost always limits the current to more-or-less exactly the value set by "R-lim" resistor. What factors affect the precision most: temperature/voltage/process?
What I'm looking to do is to set a relatively precise current limit using TPS259271.
Best Regards,
Dmitri
Part Number:TLV61046A
Tool/software: WEBENCH® Design Tools
Hello
I use Webech Designer of TLV61046A.
Specifications are as follows.
Vin：4.5~5.5V
Vout：7V / 0.32A
If simulation is carried out with that condition, an error will result.
When I tried it a lot, I get an error in Vout < about 8V.
Is TLV61046A limited in the min value of duty cycle?
Regards,
Taichi Nakamura
Part Number:LMR14030-Q1
Hi sir,
The LMR14030-Q1 feedback reference voltage tolerance is within 2%,but what does the following curve figure mean?
the tolerance for rising and falling under different switch frequency %? is it right?
Part Number:TPS2546
Hi,
There's a special reset feature on customer's NB which will cause a drop on IN pin with waveform as below (CH3). You can see it drop to a voltage around 1~2V and back to 5V. At this moment, the USB connector could be connected to any USb device or just unconnected, The question is, will such voltage drop cause any issue to our chip? Or it only causes a re-connection at most?
Thanks!
Antony
