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UCC29002: Noise at load share pin
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TLC6C5712-Q1: SPI Bus Sharing Options
Part Number:TLC6C5712-Q1
Hi,
We have a TLC6C5712 device sharing the SPI bus with other devices (port expanders, etc.)
For some reason there is no dedicated chip select line on the TLC6C5712 and therefore there is no clear methods for the device to release the SDO pin.
I'd like to know what possibilities we have to use other devices on the same SPI. Do we need to put a gate at the SDO output of the TLC6C5712?
Thanks
Stomp!.
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TPS55160-Q1: Cascading a Buck converter to the Buck-Boost converter
Part Number:TPS55160-Q1
Hi,
I require two power rails in my circuit - 6V and 3.3V. I am using the TPS55160 for the previous and TPS54110(Buck converter) for the latter. My input ranges from 4V to 9V. Since the Buck converter does not have the required input voltage range, I tried connecting the output of the Buck-Boost to it. But this caused a drop in the output voltage of the Buck-Boost to about 4V and neither of the power requirements were fulfilled. Can someone help me with what went wrong, and if there is some modification that can solve the issue? I am thinking of using another buck converter with a larger input range if I don't find any solution to this.
Thanks!
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TPS92692: About TPS92692 fPWM Question
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UCC28700-Q1: Controller IC doesn't providing switching wave
Part Number:UCC28700-Q1
I am using UCC28700-Q1 for DC-DC converter. The designed circuit is same as per the typical application circuit mentioned in datasheet of IC (Page No.17) which is modified for DC to DC converter with Vdd= 12 V.
But while testing the circuit, the voltage at Vdd pin of the controller (with respect to ground) is continuously changing between UVLO threshold i.e. 8 to 21 Volts. ( After reaching 21 volts, it again comes back to 8 volts and starts increasing to 21 volts)
Is it the reason behind not providing switching wave?
What is the procedure for testingUCC28700-Q1 Controller separately?
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TPS62172: Output capacitance limit
Part Number:TPS62172
I’m planning to use TPS62172 to supply 3.3 V to a load that will vary between ~100 mA and ~350 mA. Referring to Table 1 in the app note, Optimizing the TPS62130/40/50/60/70 Output Filter, I see that the converter should be stable with a 10-uH inductor and an output capacitor no larger than 22 uF. I’d like to use 10 uH to keep the converter in continuous conduction mode.
With respect to that 22-uF limit, to what extent do I need to consider the distributed capacitance of my board—all of the decoupling caps, as well as the capacitance between power and ground planes?
Also, Table 1 indicates that “effective” capacitance is one-half of the nominal capacitance. Is that a reference to the voltage coefficient of capacitance of (non-COG) ceramic caps?
Thanks for any insights you can give me...
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LMZM23601: Module goes pop!
Part Number:LMZM23601
Hi,
I have a design using this device and I'm following the design to a T, yet I'm getting 12V showing up on VOUT and causing everything to pop. The only thing I can think of is that Cin is not right next to Vin. Note that the person testing this after two boards failed did not hook up Cout. Is there any reason why this should fail? Note that only the buck and C1 were installed and EN was shorted to Vin. Vin is nominally 12V.
If the input voltage comes up slowly, Vout is quite low and the device gets extremely hot. I'd swear the device was installed backwards or something, but his pictures clearly show the dot where pin 1 should be and everything looks good.
When everything was installed properly and EN was pulled low, he saw +12V on the output. This was with both C1 and C2 installed. After testing, he also saw +5 shorted to ground, but this was not the case before powering it up.
(Please visit the site to view this file)
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TPS53622: CSD95377 controller selection of VCCIO
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TINA/Spice/TPS62085: Spice model doesn't work
Part Number:TPS62085
Tool/software:TINA-TI or Spice Models
Hi Team,
I'm using TPS62085 spice model in our website, but it come out an error when I try to import into TINA.
I check the model, it shows like below. I tried another spice model of TPS62130, the same error come out. Could you give some comments?
Thanks and Best Regards,
Will
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TPS27081A: TPS27081 Load Switch Leakage Voltage Issue
Part Number:TPS27081A
Hi team
Could you help check this issue ?
Turn On the DC3V3_RF_PWR_3, UN4 TPS27081 Load Switch will have the Leakage Voltage on the
Output DC_3V3 without the EN control.
DC3V3 Load Switch TPS27081 Leakage Voltage Issue
We have remove RN54 , DC_3V3 is 0V
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ULN2003B: ULN2003B
Part Number:ULN2003B
I am using ULN2003B for my PWM switching circuit, as shown in attached.
A 100 Ohm resistor is serial connection to restrict the current.
Input is 3V3, 100Hz & 10K Hz PWM signal. Output is supposed to be 24V PWM.
I did two batch samples. The first one is quite normal, very good behavior of ULN2003B as in the 1st oscilloscope picture. However the 2nd batch samples behave strangely which vibrating symmetrically with respect to the 24V line, as shown in the 2nd oscilloscope picture. Can anybody advise me what I might have done wrongly.
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WEBENCH® Tools/LM5023: LM5023_QR Flyback Power supply
Part Number:LM5023
Tool/software: WEBENCH设计工具
Hi!
I use LM5023 to develop a boost power supply, VCC auxiliary supply voltage is 24 V, power MOSFET voltage is 3 V. Request to raise 3V to 36V, there are problems in debugging, special help support, thank you!
The current problem is that the output voltage can only be adjusted to 13V can not be raised, transformer parameters for PQ2016, primary use 3TSs, auxiliary winding is 4TSs, output winding is 18TS.LP:2.8uH.
This is a two-way DC/DC converter.(Please visit the site to view this file)
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ISO5452: SIC short circuit protection
Part Number:ISO5452
Hi
I'm developing a motor controller using the ISO5452 as the gatedriver controling a SIC mosfet with a Ron of 0.03 ohm
I'm looking into how to decrease the current that the gatedriver shuts down on, the circuit looks like this:
diode with Vf of 1.3-2 V in series with a resistor R, following the design suggestion in the datasheet
To avoid a redesign I need a solution which either adds a diode with larger forward voltage or increases the resistor value R
I'm looking for a solution where the gate driver shuts down at approx 80 A, giving the following calculation
(9V- Vf-80*Ron)/500uA = [8900 10300] ohm for R
Is this calculation correct, can I just increase the resistor R or is there another way to achieve the short circuit protection?
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BQ29209: BQ29209 cell balance circuit doubts
Part Number:BQ29209
Hi,
first of all, I'm sorry for my poor experience about battery management circuits.
I have to put in series two Li-ion batteries (3,7 to 4,2) in order to get more voltage from them. I focused on the BQ29209-Q1 but I have some doubts about it I hope you can clarify:
- Is the Bq29209 also a battery charger or just a device which takes care of unbalancing issues ? If not , is any battery charger suitable?
- From the datasheet I see that there is an external network to do if the automatic confguration cant make its job. How can I Know if I have to design the external network or keep the automatic configuration ?
- From the datasheet , the recommended VDD is 10V. Can I use 12Volt coming from another big battery on its input? If not could you suggest an LDO in order to get 10V on output (current rating) ?
Hope you can help.
Thanks in advance for your support.
Nico
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LM74610-Q1: LM74610-Q1 reverse polarity circuit
Part Number:LM74610-Q1
Hi,
I want to protect my circuit with reverse polarity.
I see that the LM74610 could suit for my purposes. I have some doubts I hope you can clarify:
- From evaluation board I see the device could prevent reverse polarity during negative spike when it's working (dinamically). Can it prevent reverse polarity at the begininng when the operator connect the input power supply in a wrong way (exchanging + with -) ? I suppose yes.
- My input power supply comes form a 12V battery. Should I use the TVS diodes ? I have no specification to respect but just reverse polarity.
Hope in your support.
Thanks a lot
Nico
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BQ24200: What if current during charge drops below Itaper?
Part Number:BQ24200
Hey,
So I want to design a Solar charging circuit for a battery pack with 10000mAh, for MPPT i use a SPV1040 from St Microelectronics and I need a chip that controls the charging of the battery pack. So i stumbled across the BQ24200. The only concern I have is, what happens when the charging current drops below the 25mA of Itaper during the charge? Since the solar panel is heavily current limited it could happen that the charge current drops below this value. Is going to be a fault issued? If yes then how to disable this fault?
My problem with this whole circuit is that I'm using such a big battery pack that no ordinary charge controller is suitable, because they have timer's that are always going to be issuing a fault, because the battery pack is not full. Is there a solution to this problem?
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LMR23630-Q1: Optimal placement of two DC/DC Convertors side by side
Part Number:LMR23630-Q1
Hello TI,
What precautions should be taken when placing two LMR23630s side by side? Do I place them orthogonal to each other or parallel? The Vin and Vout paths are similar to that in the evaluation board keeping the loop area for the high di/dt components of the pulsing current as small as possible.
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BQ24196: OCP not recovery at OTG mode
Part Number:BQ24196
Hi,
In customer's production line they had tested short protection fuction in OTG mode. The OTG output is from VBUS pin rather than PMID pin.
Test procedure is
a) Putting the bq24196 in OTG mode and check the output voltage if correct.
b) short VBUS pin
c) Release VBUS pin and check VBUS pin output recovery.
Recently they have some parts could not get VBUS recovery. But I could'nt find any spec say the over current protection could recovery.
My Question is
a)If short VBUS pin at OTG mode, which mosfet (Q1/Q2/Q3) will turn off first, and how to recovery from protection?
b)If direct short VUBS pin ,whether or not the mosfet be damage?
c)Dose OCP fuction detect bidirection current or just one way?
Thanks
B.R.
Jeff Chen
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BQ24170: Battery detection issue after battery reconnection
Part Number:BQ24170
Hi,
I'm working on a device with integrated battery charger based on BQ24170. The battery pack is 3S3P Li-ion 18650.
Everything works well, except battery detection after it is reconnected, i.e.:
1. I connect PSU to the charger. Battery is not connected. Power consumption shown on PSU is circa 0A. Voltages measured in this state are shown in green colour on the schematic attached below.
2. Then I connect the battery pack. After a second or two it is detected and normal charging process is started with correct current according to what is set by resistors.
3. Then I disconnect the battery. BQ should detect its absence, but is looks like it is still charging and simultaneously battery detection algorithm is running (voltage on SRN goes up and down in a 1,5s cycle). Current consumption in this state is about 17mA. It seems that battery detection (discharge via SRN pin) does not work correctly because capacitors on VBAT line are not discharged/charged as expected because of current flow from SW pins (there is no other possible source). Voltages measured in this state that differ from those taken in point 1 are shown on the schematic in red.
I even disconnected the system to be sure it does not influence this behaviour and cut connection between Q2 and SRN pin to check if this isn't a source of high and constant voltage on SRN pin.
I also resoldered BQ chip to check if it is not damaged, but nothing had changed. PCB is 4 layer. L2 is Vishay ihlp3232dzer2r2m11 2,2uH/10,2A.
What could be the reason that battery absence is detected only once at power up and then this is not working? Could this be a PCB layout issue?
My schematic:
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LM3429: Pulse mode driver
Part Number:LM3429
Hello,
I am looking for a boost converter to convert 24V (BAT) => 80V to over-drive a LED array (Vf ~ 80V - If ~ 4.9A - rD = 3.56 Ohm) at pulse width of about 200us (f ~ 20Hz).
I have run some tests using LM3429, injecting the pulse at nDIM (pin-7) but I cannot get a good response time from the driver at 200us pulse width. It works pretty well down to 1-2ms range pulse width but seems slow for 200us pulse.
I am wondering what would you recommend for over-driving a LED array (Vf ~ 80V - If ~ 4.9A - rD = 3.56 Ohm - pulse width ~ 200us - f ~ 20Hz)?
#1 - Using the nDIM of an LED driver such as LM3429 (using PWM input for pulse mode operation)
#2 - Using a boost converter such as LM5022 at about 0.6A, charging a big cap and then using a switch to dump the big cap charge into giant LED
#3 - If I use a LED driver (i.e. LM3429) and keep the LED driver in continuous mode (always running nDIM=Hi) and control the big LED array (load) using an NMOS low side switch (100us, short pulse controls the NMOS gate) then does it make a difference to use a boost converter (i.e. LM5022) instead of LED driver (i.e. LM3429)?
In other words what is the difference between using a LED driver (i.e. LM3429) vs a boost (i.e.LM5022) about what I described above, would it be the same?
Please let me know your thoughts.
Regards,
-Reza
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