Part Number:TPS25910
What is IC-LOAD in equation 11? Is that "-" a just a hyphen or is it subtraction ? Is there an error in the document as IC is never really defined ?
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TPS25910: Question regarding equation 11
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TPS24750: Please send details data (i.e. scope plots) of reverse current protection when using the external blocking FET
Part Number:TPS24750
Please send details data (i.e. scope plots) of reverse current protection when using the external blocking FET. I don't see anything in the datasheet on this. We would also like to know how quickly this part responds to a reverse current fault. Clearly it depends on the FET used, but please point to some useful info here. Many thanks!!
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BQ78Z100: Device Type between two bq78z100 ICs does not match - why?
Part Number:BQ78Z100
My customer has been having issues in communicating with the bq78z100 on his board:
The two bytes for device type on the EVM are the third and fourth byte of the response in Little Endian so that would be the "00 11" which if we reverse them gives us 0x1100 which is what is shown on the left-hand side of the screen shot next to the chip icon.
For the device we have on our boards this same command returns third and fourth bytes of "00 01" in Little Endian. When reversed that is a Device Type of 0x0100 which does not correspond to the BQ78Z100 but apparently corresponds to the BQ34Z100:
http://e2e.ti.com/support/power-management/f/196/t/552452?tisearch=e2e-sitesearch&keymatch=bq78z100
The list in bqStudio has device 0100 matching up with a bq35100:
While 1100 is for the bq78z100:
The chips in question are labeled as BQ78100 on both the EVM and on our PCBA, but they do not return the same Device Type...and that is a concern.
What might be the problem here?
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UCC2897A: Inquiry about selection of output inductor
Part Number:UCC2897A
Hi Team.
The customer is asking for data to calculate the output inductor for UCC2897.
I can see the formula to get the output inductor from SLUA535(4.1.1 Output Inductor).
I recalculated the condition on SLUA535 once again.
However, the result is different from the SLUA535 as shown below.
- My calculations
dILo = 30A * 0.15 = 4.5A
Lo = (3.3 / (4.5 * 30 * 225 * 10^3)) * (1 - 0.3 ) = 7.6 * 10^-8 = 0.076uH
Please tell us how to calculate the maximum and minimum values of the output inductor for UCC2897A.
Thank tou
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UCC2897A: Inquiry for the relationship between main FET switching and output inductor
Part Number:UCC2897A
Hi team
My customer designed the circuit with reference to PWR758.
Increasing the output load as shown below changes the Vds value of the switching FET.
- Pink : Vds(Switching voltage for FET) / Green : Inductor Current
The PWR758 EVM does not change the switching voltage(Vds) even when the output load varies.
When the output inductor is subjected to aging test with 22uH applied, the transformer generates heat and a switching oscillation occurs.
The circuit diagram and each measurement point are shown below.:
The pin map of the transformer is different using the circuit library I used.
Please refer to the following for transformer information.
Please check and reply the following :
1. Why the Vds of the UCC2897A FET changes when the output inductor is changed.
2. What is the cause of transformer heat generation and FET oscillation.
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UCC27201: 120-V Boot, 3-A Peak, High Frequency, High-Side and Low-Side Driver
Part Number:UCC27201
Hello Sir/Madam,
Greetings!
the application note explained in this above mentioned data sheet consists of voltage divider circuits between the gate of the mosfet and the output of the gate driver IC. and also there are some capacitor of 22pF(may be Coupling capacitor) used
it would be help full to me if i can know the reason for connecting voltage diver circuit and 22pF capacitors in that circuit.
Thanks and Regards
Divya
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UCC28700-Q1: Voltage at VDD pin is continuously changing between UVLO threshold i.e. 9 to 21 Volts & No DRV signal at DRV pin
Part Number:UCC28700-Q1
Hello,
I am using UCC28700-Q1 for DC-DC converter.Below is the schematic of the same. While testing the circuit, the voltage at Vdd pin of the controller (with respect to ground) is continuously changing between UVLO threshold i.e. 9 to 21 Volts. ( After reaching 21 volts, it again comes back to 9 volts and starts increasing to 21 volts) and controller does not producing DRV signal.
Design Specifications:
Vin (min)= 250 Vdc
Vin (max)= 400 Vdc
Vout= 12 Vdc &Iout= 0.8 A
Vauxiliary (VDD)= 25 V
Maximum desired switching frequency: 100 KHz
Targeted efficiency: 90%
Discontinuous conduction mode with maximum duty cycle (Dmax)= 0.465
I have also applied 25 Volts VDD supply externally and checked the VS pin voltage. But still controller does not producing DRV signal.
Below are some observations with VDC(in)= 250V & VDD(external)= 25V
1. Voltage at VDD pin w.r.t. ground= 24.2V
2. Voltage at VS pin w.r.t. ground= 3.8V
3. Voltage at DRV pin w.r.t. ground= 0V
Following is the circuit diagram of the Test Setup I am using:
Please help me with the same.
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TIDA-010039 Source Code
Hi,
I am Looking for the source Code for the reference design TIDA-010039.
Where can I get it ?
Thank you
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LP3878-ADJ: set minimum output voltage
Part Number:LP3878-ADJ
I would like to obtain the minimum voltage with a lp3978adj (1V). Do I just need to tie vadj to vout ?
Thank you.
RG
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LMZ10500: Programmable output voltage
Part Number:LMZ10500
I'd like to use LMZ10500 as termination voltage source for a hi-speed signal with Rload = 50. I use I_DAC output to program the LMZ10500 output. Is there any special consideration for the LMZ10500 ?
+---------+
| BIAS T |
single-ended 10G serial signal ---|-C--+----|----50R----GND
| | |
| L |
+----|----+
|
Thank you very much.
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TPS23755: What is highest switching frequency?
Part Number:TPS23755
Hi Team,
I am looking to design one 12W PoE controller flyback, size and volume are very critical and I would like to switch it as fast as I can. On the datasheet for TPS23755 or same family, it only claims 250kHz as a typical value. However, the figures show some other frequencies but there is no upper limit in the datasheet. It would be wonderful if I can have this information.
Thanks.
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BQ76940EVM: Cell Voltage ready 50mV on cell 6 but 5.167 on Cell 7. Actual voltages both are 3.59V.
Part Number:BQ76940EVM
I have a 8P14S battery pack using samsung 30Q. I have wired everything up and was going through the quick start guide. I was starting with just my AFE circuit so I had the J7-SDA, J6-SCL, Alert, Regout, SDA, and SCL jumpers pulled as I am using the EV2400 for comms through the I2C port. I had everything working 100% and got to the bottom of the quickstart that was proving to show proper Culomb Counter reading as I discharge at 7A. My batteries were sitting at ~50% so I thought I would see if I could charge. I disconnected the load and put two pins in for my charger. I set DSG_ON to off and CHG_ON to on. I then plugged in my 2A Charger which was sitting at proper voltage. Coulomb counter made sense and I decided to leave it connected for 10 minutes as a test. When I came back to it I noticed my Cell voltage for 6 in my V/T/I stack was sitting at .054V and my cell 7 was sitting at 5.172V. All other voltages were sitting between 3.58 and 3.59. When I tested the voltages at each test point the voltages where all at 3.7ish including 6 and 7. I have been looking over the schematic and can't see what could be the issue. I then tried leaving my - and + on and took all the cell wires off to run with the simulator switches. This time all the voltages went to 3.6ish except for cell six still sat at ~50mV. I tried discharging a bit which works, then I rebooted everything but still there is an issue. Is the board broken? I don't know where to go from here.
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LMZ21700EVM: LMZ21700EVM Design Files
Part Number:LMZ21700EVM
Hi everyone,
I couldn't find the design files for LMZ21700EVM board. If possible can someone send me the files ?
Thanks!
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CSD17483F4: Plating Finish
Part Number:CSD17483F4
I also need to know the plating finish on this part. The material declaration page given in the original answer does not contain that information (it is blank for the finish). It looks to be gold, but I need to determine if it requires refinishing per J-STD-001. Can you confirm plating and gold thickness?
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BQ2057W: STAT output question
Part Number:BQ2057W
Good evening....
I am using a BQ2057W (8.4V) part and want to take the STAT output to an MSP430 input....The MSP430 is a 3.3V part.....The STAT will be driven, low, high or tri-state.....I would like a cheap solution that will translate for me to the MSP input....According to the BQ datasheet STAT will be at a minimum of VCC-0.5V when it is high....My VCC is about 8.7V....This means STAT high will be about 8.7V to 8.2V......
I am well aware of using I2C MOSFET translation and am sure I can make it work with these voltages unfortunately using this solution with the BQ2057 datasheet Figure 11 on how to interface to read a tri-state won't work.....Does anyone have any ideas on this one?
Thank you
Steve
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TPS92641: Analog dimming: IADJ lower limit
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LM25118: Gain margin
Part Number:LM25118
Hello
In the document www.ti.com/.../snvu065 selected bandwidth is assumed on what basis?
For system stability what should be the gain margin value if gain margin is negative?
Whether gain margin is to be more negative? or less negative?
For example whether system with -22db gain margin is more stable or one with -55db is more stable?
Please help me out in this concern.
Regards
Nidhi P Shetty
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LP87565-Q1: die to package ratio in need
Part Number:LP87565-Q1
Hi,
please help our design project by providing the die to package ratio for the part LP87565CRNFRQ1.
Is there any alternatives suggested for this part?
Thanks,
Golda
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LM76002: Converter not going into regulation
Part Number:LM76002
Hello,
We are working on an automotive USB charger based on the LM76002. The application is space constrained that's why we have used WEBENCH® Power Designer to optimize for space, please find WEBENCH output and our schematic attached.
We are using a Bourns SRP6060FA-150M 15uH coil, two 47uF ceramics output caps and the cable compensation of the attached TPS2549-Q1 USB Charging Port Controller.
We now have the first assembled prototypes in our lab but the LM76002 does not go into regulation. Please find attached the resulting outputs at startup (Vin = 12V, Vsw red, Vout blue).
The internal LDO is producing stable 3.3V at Vcc. We already tried varying the switching frequency and adding more capacitance to the output, always resulting in the same behaviour.
What could possibly be wrong with the design resulting in this behaviour?
Please let me know if you need any additional information.
Thank you and best regards,
Peter
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BQ24100: IC getting damaged when battery (cell) is mounted to the end device
Part Number:BQ24100
Team,
in our application with bq24100 (single 18650 cell), it sometimes occurs that both the IC itself and also the output current sense resistor (100mOhm) are getting damaged in the moment when the battery (cell) is being soldered to the PCB. This happened already a few times on the production (initial batch production).
It seems that in the moment when the battery is mounted (and there's no power from the line) the bottom transistor of the integrated buck converter turns on and it causes the damages.
In our case, the order in which the boards are initially turned on and when the battery cell is mounted can be random.
Thanks for your advice.
Kind regards
TI Customer
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