Hi all,
Would you mind if we ask TPS62090?
<Question>
The P14 datasheet shows "When sizing R2, in order to achieve low quiescent current and acceptable noise sensitivity, use a minimum of 5µA for the feedback current I FB ."
Our customer will use following constants
-R1：47KΩ
-R2：15KΩ
-IFB=53.3μA
So, IFB is over 5uA, it will be good effective, won't it?
We need your help.
Kind regards,
Hirotaka Matsumoto
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TPS62090 - IFB over 5uA
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LMR22007 Status
Hello,
I designed the LMR22007 into a board slated for mass production in Summer of this year. Now, however, the part is not listed on TI's site (ti.com/products/lmr22007 does not work). Is this part obsolete? Is it temporarily unavailable or being renamed?
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TPS62090 - Webench simulation data(Vin=5V, Vout=1V, Iout=3.0A) and switching frequency(Fs)
Hi all
Would you mind if we ask TPS62090?
Our customer will use TPS62090 as following conditions;
-Vin : 5V
-Vout : 1V
-Iout : 3A
-Fsw : 2.8MHz(FREQ pin connects to GND)
<Question1>
When we simulate above conditions of Vin, Vout and Iout, we could not simulate.
Then, it showed the message "For Vout<0.6V, current limit of 1.5A is being exceeded for the given design condtions during startup." on pop-up window "Parts Not Found". Please refer to the attached file.
(Please visit the site to view this file)
So, is it possible to achieve above condtions? or not?
<Question2>
We could not find out the switching frequency on the datasheet P6 at above conditions;
It will be approximate 2.2 MHz, won't it?
Kind regards,
Hirotaka Matsumoto
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TPS62736, TPS62743, TPS63031 current problem
Hi,
I want to use TPS62736, TPS62743 Buck and TPS63031 Buck-Boost converters in my designs. But i have some concern:
I need regulated voltages for my CPLD that draw in all cases less than 1 mA and I want to feed my converter with a battery that can supply max 5 mA. Therefore this current limit is enough to turn on the converters?
Secondly is there any way to limit converters input current to protect my battery?
Thnx
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low power Li-Ion battery to 3V and 5V
Hi,
I am using a single cell Li-ion Battery at the input and required outputs are 3V (<30mA) and 5V(<50mA).
For 5V output, I can find two solutions TPS61200 and TPS81256. Which one do you suggest based on the power requirement?
For 3V, I can find TPS61220. How's that?
Space and efficiency are both my design concern.
Thanks,
Amir
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TPS62361 registers
Hello,
With tps62361 the voltage seem to fluctuate as we are writing to registers. Why would this happen?
Finkel
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tps65095 peak voltage on Vsw pin
hi my customer see a peak voltage higher that the max allowed on the datasheet which is Vin +0.3V.
Could you pelase explain since the datasheet on figure 13 shows opeak higher than Vin + 0.3V!!!
Regards,
Kamal
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TPS62090 - the stability(the phase margin) of the circuit
Hi all,
Would you mind if we ask TPS62090?
<Question1>
The control method of TPS62090 is "Bang-Bang" control which combines the advantages of hysteretic and voltage mode control.
As long as we use the value of the inductor and the output capacitance which is recommended on the datasheet,
we don't need to mind the phase margin, do we?
<Question2>
Our customer uses following constants;
L=1uH, Cout=22uH, R1(Rfbt)=47KΩ, R2(Rfbb)=15KΩ
So, in order to achieve low quiescent current and acceptable noise sensitivity, they use over 5µA for the feedback current IFB.
The feedback Rfbt and Rfbb are not relation the stability(the phase margin) of the circuit, are they?
Kind regards,
Hirotaka Matsumoto
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TPS62133 power supply design (layout)
Hello TI and forum members! I am designing a 5V 3A power supply with the TPS62133. The most interesting charateristic of this regulator that attracted me was its high efficiency at low output currents (above around 81% @ 30mA and up to 86% @ 3A), which for higher output currents is not around the 94-96% other regulator achieve but more than doubles the maximum efficiency at very low currents when compared.
I have several questions regarding the appropiate layout of the of some traces and components:
1. The VOS line in the EVM (SLVU437A) is routed from the VOS pin 14 through a via to the bottom layer, then through another via to the top layer and finally reaching VOUT just at the point where the output capacitors C3 and C4 are connected together with the inductor L2. This is not exactly the point where the load will be connected, which is the output connector J9 in the EVM. In my layout I have it routed in the same manner, not connecting the VOS pin to the point where the load will be connected but rather to exactly in the output capacitors (C2, C1) following what is stated in the datasheet and EVM. In other designs the pin that senses the voltage should be connected to the point where the load will be connected for the controller to be able to regulate the voltage at the point of interest. My question is: is the connection in the EVM good for all cases in this chip? Are there any assumptions made when making this connection at the output capacitors rather than the load? Please refer to image VOS ping routing.png
2. Loop Area for high frequency load currents: due to space/position restrictios in my application, the high frequency output load current needs to make a 90° turn near the IC. Since the radiated energy is proportional to loop area formed by the load current (as is also stated in the TPS62133 datasheet SLVSAG7C) I am not completely sure a solid ground plane would be the best low impedance/EMI Absorbing path to be used, since it would enclose a relatively large area. Instead, I was considering to route this return path just above the output current path, so that the loop area is decreased to a minimum. Would this be a better approach? or should the solid ground plane still stand despite the possible loop area? Under the understand that high frequency signals will choose the lowest impedance return path, this path would be just below the output current path, in which case the solid ground plane would be unnecessary (at least for high frequency signals). The best decision is not clear for me, so is there any recommendation? Please refer to image Return Path.png
I would greatly appreciate any feedback on this two inputs. The board was designed following as close as possible (and sometimes exactly) to the recommendations from datasheet and EVM, so I expect a first time working board within specifications.
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Inverter
Hello,
I am looking for the adequate inverter for low jitter application. I know PWM makes some jitter. So PWM have to be excluded. Here is the specificaiton below. Is there anyone to recomend the good device?
Input : +5V
Output : -2.5V
Output Current : 500mA
Thanks,Sebeom
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tps62220 Iq < 30 uA?
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tps65095 peak voltage on Vsw pin
hi my customer see a peak voltage higher that the max allowed on the datasheet which is Vin +0.3V.
Could you pelase explain since the datasheet on figure 13 shows opeak higher than Vin + 0.3V!!!
Regards,
Kamal
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TPS62361B wake at 1.77V?
Good Morning,
I have a customer interested in whether or not the part can wake up at 1.77V and work down? How is this implemented?
Thank you!
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TPS62090 - the power dissipation
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TPS62085 / Switching frequency variation
Hi Chris,
I found following thread that discussed about switching frequency of TPS62085.
Now I also found this behavior on EVM, but I can't find such behavior from information in datasheet. From fig.1 in datasheet, I assumed that it should be 2.4MHz at 3A load but it was approx. 1.4MHz with 3.3V input. On the other hand I can see 2.4MHz with 5.0V input. So please explain the mechanism of this switching frequency variation.
Please refer the waveform at 3.3V and 5.0V input I measured.
(Please visit the site to view this file)
Best Regards,
Sonoki / Japan Disty
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tps62220 Iq < 30 uA?
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TPS62361B wake at 1.77V?
Good Morning,
I have a customer interested in whether or not the part can wake up at 1.77V and work down? How is this implemented?
Thank you!
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TPS62090 - the power dissipation
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TPS62090 - Enable pin current
Hi all
Would you mind if we ask TPS62090?
How much is the value of Enable pin current?
We could not find it on the datasheet.
Kind regard,
Hirotaka Matsumoto
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TPS62080 anti-shoot-Trough circuit
I think TPS62080 has anti-shoot-through circuit. However there is no in block diagram of datasheet.
Where is there anti-shoot-through circuit? I think it is in gate driver block. Is my idea correct?
Best Regards,
Kohei Sasaki
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