Part Number:TPS65400
Tool/software: WEBENCH® Design Tools
this is the ripple
this is the current waveform when position is 10ms
this is the current waveform when the position is 500us
this is the current waveform when the position is 200us
this is the current waveform when the position is 2us , and Fsw = 1.287MHz
and this is my schematic
we think that the problem is the set of 'C238' and 'R245'，but we can't find the suitable set making the output stable,or how to caculate them.
thanks.
Part Number:LMR23630-Q1
Hello TI,
we are developing a telematics device. In order to save space, I was wondering if we could place the LMR23630-Q1 and the related external components on the BOTTOM layer instead of the TOP component layer.
We are considering either of the following stack ups shown at the bottom of this post, depending on our signal density either a 4 or 6 layer board.
The idea is to have the RF components on the top layer and the DC DC convertors and other non RF components on the bottom layer, hopefully also reducing board area in the process.
1. What does it mean to the switching signals that would have the VCC plane as reference plane instead of a GND?
2. Should additional capacitors be placed to enable the return current to follow from the VCC plane to GND?
3. Will I be able to use the TOP side for other non RF components?
Is this even worth the effort to save space on the board?
Part Number:TPS65131
Hi Team, I have designed the dual power supply using the IC TPS65131 to get +15V and -15V with 5v as input.
The values of resistances, capacitances and inductances are chosen according to the datasheet.
When I supply +5V to the circuit with a steady voltage source, the input voltage drop to 2.3V, and the VOPS is +10V, VNEG is -2V, VFBN is +0.8V, VREF is 1.0V
I try to find the reason, so I take away the inductances L2, L3. and the values of reference voltage are normal.
Please let me know the changes/updates required in the design, so as to get the positive voltage of +15V and the negative voltage -15V.
I really appreciate your help in this. Thank you.
Part Number:LM5118
Tool/software: WEBENCH® Design Tools
Dear Team,
My customer is using Webench to verify their design.
But Webench mention Cout voltage rating will need 162V.
Can you help on double check the reason?
I think 100V should be enough.
- Vin => 36~60V , but component rating need up to 100V
- Vout => 53.5~57V, 55V- typ
- I out => 2A,
Part Number:TPS23751
What is the purpose of Cio in the typical design from the data sheet?
I have a layout with a noise problem at a specific frequency and it appears to be related to my layout of the POE circuit. What is this capacitors purpose and could it be removed without introducing a vulnerability to the overall design. Looking at the design I can only guess it is used to provide a return path for leakage due to the primary - secondary capacitance of the Flyback Transformer which would suggest removing it might make noise emissions worse. Any insight would be helpful.
Part Number:BQ24088
Hi,
We are designing a 1cell Li-ion custom battery pack.
The issue is that in order to fulfill one certification the design must pass, the battery pack shall have a set of diodes in the charge path connector and the Voltage Bat monitoring shall be current limited using a 10K resistor.
The custom battery pack simplified architecture is shown in this figure:
We have choosen the BQ2408x IC for the charger design, due to the Bat voltage monitoring and charge is made via different pins. So the charger connector will be tied to the BAT pin and OUT pin of the BQ2408x.
Will we have any problem due to the 10K resistor or the diode stage?
Best Regards,
Juanjo
Part Number:TPS7B4254-Q1
Team,
IN is battery at 12V and ADJ is currently low. What is the timing from ADJ considered to be high (>=2V per the test parameters in Electrical Characteristics ) to OUT of the LDO ramping and tracking ADJ?
Part Number:LEDSPIMCUEVM-879
Hello, I would like to get this evaluation board for driving the TPS92518HV eval board. It seems that this board is presently unavailable. Can you tell me when it will be available? Thanks!
Part Number:BQ40Z50
Hi,
i also need an Indicator for the BQ in Shutdown or Enable in some way. I looked at the PBI Pin and did see that even though it does not reflect the Shutdown 100% it still drops down after some time. I dont want to supply any other circuit directly but instead just put a Gate from a FET on it (to only use this Pin as Signal and not as source) and would draw the equivalent of around a 2MOhms Resistor from that Pin. Would this be an approachable solution ?
I also thought about using the BTP_INT or one of my unused Thermistorpins to get any other Signal that Indicates a shutdown BQ in wich the Timing is not critical as long as the signal toggles Off/On at all.
Do u have any Suggestions or Ideas ? I was hoping that i can use the TS Pins as GPIO Pins like in the new bq40z80 to Map it accordingly but R2 does not support something like that.
Thanks in advance
Robert
Part Number:BQ24103
Hi,
We are designing a 1cell Li-ion custom battery pack.
The issue is that in order to fulfill one certification the design must pass, the battery pack shall have a set of diodes in the charge path connector and the Voltage Bat monitoring shall be current limited using a 10K resistor.
The custom battery pack simplified architecture is shown in this figure:
We have choosen the BQ241Xx IC for the charger design, due to the Bat voltage monitoring and charge is made via different pins. So the charger connector will be tied to the BAT pin and OUT pin of the BQ241xx.
Will we have any problem due to the 10K resistor or the diode stage?
Best Regards,
Juanjo
Part Number:TPS61085
Hi,
I'm looking at a design (using the TPS61085) which requires a maximum of 100mA of current output. When calculating the inductor value using equation 5 in the datasheet, I end up with a result in the order of tens of uH which isn't surprising given the low current.
However, the previous paragraph in the datasheet suggests using an inductor between 3uH and 6uH and presumably using such a value would also violate the recommendation of maintaining ripple under 35% of the load current.
What is the recommended approach when dealing with low average currents?
Thanks
Part Number:CSD95379Q3M
Hi,
I'm planning to incorporate CSD95379Q3M in a half bridge push pull design (a half bridge on primary side, and output without inductor). This design has intrinsic ZVS behavior, which saves power.
However, to achieve ZVS, it must operate with considerable amount of dead time between high drive and low drive.
To implement this feature, I need some data from TI:
1. What's the switching node capacitance (Cds_hs+Cds_ls) at 5V Vbus?
2. How can I control the dead time?
So far, my plan was to use the tri-state to trigger a dead time using 2 PWM signals, one for tri-state driver OE, the other for real PWM signal. That should give a 3-level signal.
Another question is on the SKIP pin. I would like to have it floated when I don't need it, so I can save some 122uA of current at idle. However, is there a guideline on how to implement very low power sleep mode? I noticed the datasheet saying do not float SKIP during power up, so how I'm supposed to float it?
I can drive SKIP pin with a tri-state-able MCU pin, but at power up, MCU pins are all tri-stated, so SKIP will be floating. I can only drive SKIP high or low after MCU boot up, which takes time. How should I connect this pin?
To be clear, the behavior I want is that the chip does very low power when I enter sleep, and they chip goes to FCCM when I want it to run.
Thanks,
B.G.
Part Number:UCC28911
Hi teams
This is Gabriel Xu from South China OEM team, FAE for Anjubao, nice to meet you.
We found some issue about UCC28911 and need your help.
When the UCC28911 startup, VDD voltage ramp up to 9V and start to drop.
Internal MOSFET switching couples cycle and stop.
This project has MP already and found 10% device will have this issue.
After the customer replaces the controller with a new chip, the issue solved.
I am wondering to know what I should do to confirm is this a quality issue or application issue?
The VDD and Vdrain waveform have shown below.
Thanks in advance.
Part Number:TPS50601-SP
What is the best way to test the parameter Boot-PH ULVO. For the error amplifier source/sink do I simply input 1V at the comp pin and read back the current at that pin? I would assume that I would need to open the RC network on that pin to make the measurement.
Part Number:DS3658
Team,
My customer needs the following clarification. Any light/background you can shed would be much appreciated.
We are awaiting delivery of some parts, the TI DS3658, I believe from a distributor. The delivery is being held up because the datasheet currently says that I-input-high is 1 uA max. Our spec says the max current is 10uA.
Digging through old datasheets, I found that when it was a National Semi datasheet, the Input High max current was 10 uA, but as soon as it changed to a TI datasheet, the max
value changed to 1uA. Another oddity is that the "typical" value on both datasheets is 1uA. It seems odd that the Max value would be the same as the Typical value, doesn't it?
Is there a way you can check this? I have a feeling that maybe the value was just transcribed to the new datasheet incorrectly.
Regards,
Aaron
Part Number:TPS2372
We've had a board developed for us that uses TPS2372 as the PD interface. This then supplies power to a tps54560 switcher set to supply 12V at 2A. 3x MR16 LED bulbs are to be connected to the output of the PCB. There is also a switch circuit to allow the LED bulbs to be turned on/off. The MR16 bulbs used are 5W LED bulbs that can work on either 12V AC or DC (constant voltage). I expect that within the bulb, there is circuitry to drive the LED with constant current and also allow dimming.
Having received the PCB's for test, i have noticed the following -
In (2), (3), (4) and (5) the PCB correctly classifies as class 4 and is confirmed as such with the PoE commander software. Even when the bulbs are switching off in (2) and (3) the classification is never re-done.
Could you suggest where to look for the source of the turn off in (2) and (3). To me, the PSE is supplying power correctly as the PCB classifies and maintains this, plus there is no error flag in PoE commander.
I believe that the tps2372 might be causing the blip, but i need to investigate further tomorrow, but i cant explain why all is well in scenario (1).
Part Number:TPS56628
Application brief SLMA004B states, "Solder mask should be applied to cover the entire bottom side of the PowerPAD vias to prevent solder wicking. This includes full solder mask coverage over the vias." Our board house as expressed concern over possible outgassing due to the vias being open an covered by paste on the top and closed by solder mask on the bottom. Is this truly a concern or should we tell the board house to follow TI's instructions?
Thanks,
TL
Part Number:BQ76PL455A-Q1
Dear,
What is mean "program cycle"?
Is it number of times the eeprom is erased? 5 cycle?
Part Number:TPS65400
In the TPS65400 EVK circuit and the PMP11414 reference design, capacitors are placed across the upper feedback resistor to shape the closed-loop response. In the EVK, these are C11, C19, C27 and C37.
I do not see any mention of these capacitors in the TPS65400 data sheet or the EVK user guide. When are these capacitors required and what is the best way to compute the proper values?