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TPS3831: P2P Direct Replace
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TPS2041B: P2P Directly Replace
Part Number:TPS2041B
Dear Team,
Do we have a solution can directly replace this one?
AP2141DMPG-13 |
BR
Kevin
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TPS3823: TPS3823-33 & TPS3823A-33
Part Number:TPS3823
Hi,
Could you please tell me what's the difference between TPS3823-33 and TPS3823A-33? I can NOT find the answer from the datasheet.
Thanks.
Kevin Xiong
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LM5119: Can LM5119 output negative 12V voltage?
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LM317A: Using ceramic capacitor of LM317A
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BQ30Z554-R1: BQ30Z55 Can't turn on the CHG FET issue.
Part Number:BQ30Z554-R1
Hi sir,
my customer is using BQ30Z55 for 2S battery pack ,now when they test the function, they find that if not connect the SMBUS, in charging mode , BQ30Z55 can't turn on the CHG Fet. it only can be active by connect the SMBUS or connect a load to discharge, the CHG FET can be turn on ,could you please help to suggest which setting will result this issue?
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TPS61220: Low input voltage boost switcher for single cell PbAcid (1.8V - 2.2) with Iout max > 200mA
Part Number:TPS61220
Hello;
I'm searching the a booster converter for a single lead-acid cell to 3.3V @ at least ~220mA. I'm found the LT1300 and am looking for an alternative/cross. I see your tps6122x, but its max output current appears limited to <~125mA @ Vin = 1.8. Will you please suggest a TI switcher for this application.
Thanks in advance.
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TPS60301: TPS60301
Part Number:TPS60301
I'm using TPS60301 for my application to generate 3v from 1.5v supply.
The charge pump is wired as provided in the datasheet, using five 1uF capacitors.
The enable pin is connected to the input pin.
Sometimes it is noticed that the input and enable pin indicate only 0.7v against the expected value of 1.5v, though power supply indicates 1.5v. once this problem occurs, it stays for a long time. If switched off for some time, the output comes back again. I'm using Out2 for my application.
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BQ76PL455A-Q1: Linear & Step by Step
Part Number:BQ76PL455A-Q1
Hi,
We are using BQ76PL455A-Q1 *2 for 26 series cell. The chart below shows the voltage(26 cells) of charging.
Why are some cells with a linear voltage, some of which are step-by-step?
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BQ24610: Voltage dip due to inrush causing UVLO trip
Part Number:BQ24610
I have an application using a bq24610 in which a high inrush current coming from the ACPWR node is causing a momentary voltage drop. I observe PVCC and the VCC input to the battery manager dipping below 3.85V which trips the UVLO limit and switches over to battery power, in this application we want to avoid switching to battery power during inrush.
Is it acceptable to either increase the resistance of R22 or capacitance of C12 shown in the below image to hold up the VCC input to the bq24610? If so what is the maximum capacitance/resistance I should consider for these parts?
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LM5021: Undefined maximum voltage on Vcc
Part Number:LM5021
I am using the LM5021 in an isolated flyback circuit. 24V DC in and 16V out.
In order to ensure that the device starts up at a usable voltage I cannot use the internal regulator but instead I create a 9V supply (from a linear regulator, there is no start-up winding) and connect this to both VIN and VIN, i.e. the internal regulator is by-passed.
My question is what is the maximum permitted value of VCC?
The data sheet SNVS359E –MAY 2005–REVISED DECEMBER 2014 is contradictory:-
"All other pins to GND 7V" but this van't be true because Vcc is 8.5V nominal!
"VCC Output only of a linear bias supply regulator. Nominally 8.5 V."
"VCC Output only of a linear bias supply regulator. Nominally 8.5 V."
and later
"It is not recommended that the bias winding be connected to the VCC pin of the LM5021. Doing so can cause the device to operate incorrectly or not at all."
We ll I can repor tthat it works just fine with VIN=VCC=+9V from an external source. What I would like to know hoever is what is the maximum for Vcc so that I can tick a box in my circuit review.
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TPS51285A: TPS51285A ----- Output capacitor of VREG3 and VREG5
Part Number:TPS51285A
Hi ,
According to TPS51285A datasheet suggestion , a ceramic capacitor with a value of 4.7 µF or larger (X5R grade or better) is required for each of VREG5 and VREG3.
If I change the capacitor value from 4.7uF to 1uF, will the controller have abnormal fucntion? Is it a critical issue to do this change?
I measured VREG3 voltage level is stable in 3.3V even though the capacitor with 1uF.
Sincerely,
Chin
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TPS65265: Dynamic Response
Part Number:TPS65265
Hi,
I am testing on a board that uses the TPS65265 to generate several voltages.
One of our supplies generated by the TPS65265, which has a nominal voltage of 1.2V, has a nominal current load of 50mA, but has transient loads of ~400mA.
We have found that there are dips on the 1V2 supply that last several hundred microseconds, and have been observed to be ~150mV from the nominal value. These deviations are causing issues for digital circuitry powered by the TPS65265
In the attached oscilloscope screenshot, green channel 2 is the voltage on the LX pin, DC coupled. Channel 3 in blue is the output voltage, AC coupled. We are using the TPS65265 in PSM mode and it is clear that the TPS65265 changes mode when this transient load takes place. It appears that the TPS65265 is not regulating the output voltage for some time after switching from PSM mode to CCM mode. Are there any known issues with this?
Thanks,
Tom Perman
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LM4140: ESR requirement of Low ESR Ceramic Capacitors?
Part Number:LM4140
Hi there,
We use LM4140 for DAC REF2.5V. SCH as below. On Datasheet page9 Figure24-26 shows a Cout's ESR value range for STABLE operation.
1.We use high quality C1005X5R1A475K050BC 4.7u, which has a very low ESR as pic below. Not sure how to decide the freq because ESR changes with frequency . Our system has DC/DC all worked at 800KHZ.
So shou we serial one resistor R1018 with Cout ?
2. I also need to ask, there is mechanical stress relief action required on page 12 of Datashseet, is it necessary ? How much Mechanical Stress/Distortion will it affect its performance? Is there quantitative relationships?
Thanks!
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LM2678: Wide Range Output application Unstability / Voltage drop
Part Number:LM2678
Hi,
I am designing a power stage using LM2678 where:
Vin: 19V
Vout_min: 2V
Vout_max: 16V
Iout: 5A.
Problem: With a 4ohm load I found that it can not go higher than 7V approx (1.75A output). With a 8 ohm load this limit appears at 10V approx. With lighter loads (16ohm ) works fine.
Half-Solution: I found Samuel Jaffe recommended increasing input capacitance as closer as possible to the Switcher (Input and GND pins). (e2e.ti.com/.../699199)
I tried adding 1uF ceramic and 10uF ceramic caps. First soldered on the pins and later on a position where would be more convinient for manufacturing. All cases helped in the same way.
New limit is on the 10V (with a 4ohm load = 2.5A output). Moreover if power stage is turned-on configured (Rfeedback) for a higher voltage will do it right. The problem is rising voltage while it is running (changing Rfeedback). Then looses tracking and falls back to 10V.
Detail: I am using an SPI configurable resistor. C59 is on the way Vin goes to the switcher, so is filters the feeded19V to both ICs.
Find schema, clean layout, added caps layout attached.
Any recommendation/advice will be really apreciated.
Thanks in advance.
Tom
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BQ76PL455A-Q1: The voltage of cell#12 is always higher than the actual value
Part Number:BQ76PL455A-Q1
Hi,
We use our own designed circuit board to manage 26-cell. Each board manage 13-cell.
We have a issue that is voltage of Cell #12 always higher then the actual value, and Cell #13 always lower then the actual value.
Board #1 and board #2 are the same. Please see following picture.
Do you have any recommend?
Best Regards,
Aaron
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TINA/Spice/LM5155: LM5155 Encrypted Spice Model can't be Imported to TINA for Simulation
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TL431: TL431 w/ buffered output
Part Number:TL431
Hello,
Background:
I am designing signal conditioning circuits that level shifts from 3.3 or 5.25V to 15V and from 15V to 3.3 or 5.25V (for interfacing between PXI digital I/O and a unit under test (UUT)). The connections will be configurable within the product, so I want to protect the inputs of my circuitry against over-voltage in case incorrect connections are made. On the low voltage side (3.3 or 5.25), I am using an input resistor (10k) connected to the anode of a low capacitance diode (2pF) with collector tied to the 3.3 or 5.25 rail. Assuming worst case of all inputs pulled to +15V, the 1.15mA per input adds up quickly for the many channels I'm using.
I want to use the TL431IB for its accuracy, but need to buffer its output to sink < 200mA. So, I have designed a simple NPN/PNP push-pull buffer w/ a 10uF output cap as shown here.
R2 (100 ohms) is used to allow limited control of the output when the base/emitter junctions are "off".
Based on the TL431 data sheet, I believe the output cap in series with R2 is OK.
Also, The JP11, R3 & R5 resistors are to allow for choosing the 3.3 or 5.25V output.
Question:
Are there any "red flag" concerns to which I should be paying attention?
Including for example: looking at data sheets for some regulators, diodes are recommended for certain conditions (e.g. turn off), such as shown in the following excerpt from the LM117 datasheet. Would this be a concern for my circuit?
Any suggestions or warnings will be appreciated.
- James
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BQ27220: Does it support low side current sensing?
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TPS54202: Instability that causes output ripple
Part Number:TPS54202
We are using TPS54202DDCR to provide 5V from the input voltage with a range of 21-25V. The output current varies between 2mA when in sleep and 40mA and 600mA in normal operation. For most part it works fine, but there is a small instability that causes audio noise, which we really need to get rid of. We have followed the design guide and also used your simulation tool to see if we can optimize this, but have not had much luck. The layout is identical to your recommendation, so we are sure that is not the issue. We changed the output inductor with various values from 10uH to 47uH, with the output cap of 3x 22uF ceramic, as recommended. The feed forward capacitor is 82pF, but have gone up to 150pF and down to 50pF with no improvement. The instability we see is not all that big and it causes output ripple of roughly ~40mV, but due to its frequency components it is causing us a lot of issue with noise that we cannot filter. Would really appreciate some insight and design guidance to get passed this. Thanks. Rick
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