Part Number:LMZ14201
Tool/software: WEBENCH® Design Tools
Hi,
i needed a 12V to -12V converter with 0.5A, got this design:
i have 2 things i dont understand in this design and will be happy if you could explain them:
1. The Cbyp capacitor see 24V and the capacitor recommended by the design is 10uF/6.3v capacitor
2. The EN voltage when input is 12V is -8.8V, the enable threshold of this part is 1.18V
Thanks,
Shlomi
Part Number:BQ27501
Hi, I have purchased BQ24650EVM-639, CC3220SF-LAUNCHXL, OPT3001DNPT, and HDC2080DMBT from Digikey.
My team is trying to create an outdoor Wi-Fi ambient tracking application.
I also ordered a 3.5 Watt 6 Volt solar panel. (Open Circuit Voltage: 7.7V, Peak Current: 550mA)
https://www.voltaicsystems.com/3-5-watt-panel
This is the battery, which I bought from Adafruit, I'm trying to charge; Lithium Ion Battery Pack - 3.7V 2200mAh (PRODUCT ID: 1781)
SHENZHEN PKCELL BATTERY CO, Model：ICR18650 2200mAh 3.7V 1S1P
This is the detailed specification
Compared to BQ25570EVM-206, I need to add a buck converter to supply 1.8V or 3.3V.
Also, I wish to track the remaining battery capacity (mAh), state-of-charge (%), run-time to empty (min.), battery voltage (mV), and temperature (°C) with TI's battery fuel gauges ICs.
Q0. Since BQ27501 is in NRND (Not Recommended for New Designs), what could be an alternative for my case?
Q1. I'm looking for a buck converter from TI that
- 1 regulated output
- adjustable Vout; I will use voltage divider resistor to create 2.9V or 1.8V system power (or fixed 1.8V)
- max current output: 150mA
- don't want ball grid array type of packages
- low power consumption
Can you give a recommendation to me with this, please?
Since the BQ24650 is using the 600-kHz NMOS-NMOS Synchronous Buck Controller, I think the switching frequency might be another issue.
Q2. I'm new with the battery gauge devices from TI. After getting a recommendation, what will be the connection when using
. the solar charger
- buck converter
- battery gauge
?
Part Number:BQ24650EVM-639
Hello,
Below is an update I saw regarding the test procedure SLUU444A for BQ24650EVM. It says that in step 2.7.1 there is an error where Vout should not be 0V. However I am not reading 12.6 Volts, as this customer had stated but rather 4.7 Volts. At this particular step in the procedure, there is only a supply voltage of 21 Volts on the Vin input and the loads are not on as instructed in step 2.6 ( they are not even connected) . JP1 is connected between pins 1 and 2, JP2 is plugged in, JP3 is connected to pins 2 and 3, and JP4 is OFF ( removed ). Can you explain why I am getting 4.7 volts on VOUT at step 2.7.1 and not 12.6 ? It looks as if you have acknowledged the mistake but it would help me greatly to know what we should be seeing at step 2.7.1 and under what conditions. I have read your comment number 2 below but I don't understand what it means with reference to the test procedure. Please help.
Thanks
Dave
1. The user guide has an error in saying that VOUT = 0V at section 2.7.1. You are correct in measuring 12.6V at this step with a multimeter. This part has a battery absent detection scheme to detect insertion or removal of battery packs. This effect can be seen clearer using an oscilloscope and is explained in detail in section 8.3.21 of the datasheet. Thank you for bringing the mistake in the user guide to our attention.
2. A standard power supply cannot sink current and cannot be used to mimic the load in this case. An electronic load is ideal, however for lower current measurements it is possible to use a Sourcemeter or a Kepco bipolar operational power supply/amplifier. Essentially you require VOUT to be held to a constant voltage and to be able to measure the current into the instrument (CV).
3. Can you describe the conditions in which you see STAT1 illuminate? If you were to remove all load, are you still seeing STAT1 light up?
1. The user guide has an error in saying that VOUT = 0V at section 2.7.1. You are correct in measuring 12.6V at this step with a multimeter. This part has a battery absent detection scheme to detect insertion or removal of battery packs. This effect can be seen clearer using an oscilloscope and is explained in detail in section 8.3.21 of the datasheet. Thank you for bringing the mistake in the user guide to our attention.
2. A standard power supply cannot sink current and cannot be used to mimic the load in this case. An electronic load is ideal, however for lower current measurements it is possible to use a Sourcemeter or a Kepco bipolar operational power supply/amplifier. Essentially you require VOUT to be held to a constant voltage and to be able to measure the current into the instrument (CV).
3. Can you describe the conditions in which you see STAT1 illuminate? If you were to remove all load, are you still seeing STAT1 light up?
Part Number:TLC5916
I know! Why the heck would anyone want to do that?!? But, what if you wanted two brightness modes--modes that extended beyond the dynamic range of the "256-Step Programmable Global Current Gain" feature?
Well, you might switch Rextin and out of circuit. The datasheet seems to imply that both states are sanctioned: Tables 7.5 and 7.6 include an IDD case where Rext = "Open".
So, is running the TLC5916/17 device without an Rext connected, in fact, an approved mode?
Part Number:LM53601-Q1
Gentlemen,
I am trying to obtain the minimum supply input voltage to which reset/FAULT get cleared for 5V fixed regulator.
Per datasheet, If voltage on Vin exceeds Vin_uvLo (3.75V) and VCC exceed Vcc_uvLo (2.75V).
I would like to clarify, is that correct for 3.3V fixed regulator and 5V fixed voltage regulator LM536015QDSXRQ1?
Please advise,
Thanks,
Arun C S S
Part Number:TPS63070
I am working on a 3.3V/2A Buck/Boost converter design which is based on TPS63070RNMT.
Below is the schematic design. All the selected components are as per the Section 9 of the datasheet.
U6 is powered by either USB (5V) or a rechargeable battery (2.8V-4.2V) as shown in the Schematic below. Expected Output is +3.3V/2A. 
USB connection is given priority in the design. If both USB & battery are connected to the board, PCB will be powered on by USB while battery gets charged.
The issue I am facing upon powering up is U6 not working as expected. Output is approx 1.2V and there is a lot of humming sound coming out of inductor. U6 is getting heat up very quickly. It is also affecting Original input waveforms and other sections. For example, USB input = 5V DC is superimposed with square wave. VBATT net on U1 also has some distortion in the form of sawtooth signal.
I am suspecting the inductor saturation issue. Did anyone face similar issue earlier?
Need some inputs from the expert.
Thanks in advance
Part Number:LM5155EVM-BST
Hello,
I would like to know the thickness of copper of the LM5155-EVM. I would like to know if there is 35µm or 70µm?
I saw in the LM5155 datasheet you mentionne the RJA is typically 60.3°C/W and 37°C/W for the EVM board.
Did you measure these data (RJA) for the MOSFET and diode used in the LM5155 EVM board?
Thank you,
JMB
Part Number:BQ24770EVM-540
I’m close to turning on my experimental setup. But before I do, I had some questions.
I’m using the bq24770EVM and the bq40z50EVM in an NVDC charger + gauge setup. The attached diagram shows how I plan to hook it all up, based on what I read in the two EVM user guides. My questions are as follows.
1.) If I need to use a second 3.3V power supply for the bq24770EVM, which I assume is the pull-up voltage for the SMBUS, should I wire this same 3.3V to J2 of the bq40z50EVM (which would normally be where VOUT1 from the EV2400 comes in)? Please see the dashed orange connection in the diagram.
2.) Why doesn’t the bq24770EVM have the same 4-pin header for its SMBUS input as the cable to the EV2400 suggests?
Please let me know. Also, please confirm that this hook-up is correct and ready to power up and test.
Thanks,
Carl Olen(Please visit the site to view this file)
Part Number:UCC28780
I would like to have my power supply enter AAM (continuous switching, no bursts) at something like 20% of the maximum output current, regardless of line voltage input. ABM burst mode creates transient spikes at the beginning of each burst when PWML switches ON while the switch node voltage can be hundreds of volts, and I would like to minimize this over most of the load range.
I am using the MathCad worksheets provided for this controller in sluc644. I have set my V.in_BUR voltage very low and tried a range of R.CS current sense resistors. In both cases the "Neutron..." worksheet recommends that a few other components change, and I have also made those changes.
Nothing comes close to what I'm after, in fact in many cases I don't even reach AAM mode at full load. What I want, I think, is reduced peak current on each switching cycle. This should enter AAM at lower output currents, and then the controller could adjust switching duty cycle to provide for the higher range of output current.
Is it possible to do this?
Hello team,
I bumped into the following device from MPS in one of my customer's applications and was trying to find an alternative TI solution.
Specifically I'm referring to the MP9486A 
Since I couldn't find any alternative through the Cross reference tool, do you have any suggestion on which is the closest part we can offer?
Thank you in advance for your thoughts!
Best regards,
Adrian
Part Number:TPS63020
Hello E2E,
I have a (hopefully) quick question on the TPS63020. In the description section (8.1) of the datasheet, it says that the boost current can be as high as 2A. However, why is this not a function of the switch current limit of 4000mA and is labeled as a blanket statement? Is this the actual current limit in boost mode or just a recommended condition?
If more than 2A is drawn in boost mode, would this impact PG? Is there an overcurrent trip event? Would the PG signal be pulled low in this event?
Thanks!
Russell
Part Number:TPS2121
Hi,
In the TPS2121 datasheet both table 2 and 3 (and related text) say at the last column that the ST Pin would be high if both inputs are invalid (INx ≤ UV OR OVx ≥ VREF). Obviously, this cannot be true if there is no power (INx=0) applied yet. However, if this is not a typo, can you please tell me the typical time that would be true (ST high) after both inputs go to zero? After that time, is it Hi-Z or ground (I could not tell from the functional block diagram?
Thank you for your help.
Part Number:TPS62097-Q1
Hello,
The layout example provided in Figure 25 of the datasheet shows that the mode and feedback resistors are placed outside of the ground pour that's on the component layer. This ground pour connects the input and output cap grounds. In a multi-layer board, where there is an adjacent ground plane (say 5 mils under the component layer), would the copper pour be necessary, and if so, would bringing in the mode and feedback resistor inside the copper pour be OK? Placing these resistors between the device and the copper pour will provide a few benefits: 1) Eliminate quite a few of the vias that are associated with them in the illustrated example, 2) shorten the feedback trace, and 3) allow the grounds of these resistors to tie directly to AGND. Are there any disadvantages to this approach, say in terms of EMI performance?
Thanks,
Narek
Part Number:BQ40Z60EVM-578
I have been trying to charge 2 Li-ion cells with nominal voltage of 3.7v with bq40z60 evm board with no results.
[ACFET] is always 1
[DSG] is always 1
[CHGSTAT] is always 1
[MaxError] is always 100%
I have all the FETs enabled and also the CHGR enable.
Please help.
Part Number:TPS62090-Q1
1. Why is the temperature item so different? Please explain why?
2. Why does the TPS62090RGTR increase in thermal resistance? Is there any change in chip material?
| TPS62090RGTR | TPS62090QRGTRQ1 | |
| temperature | -40 to 85 | -40 to 125 |
| V(ESD) Human body model (HBM) | ±2000V | ±2500 |
| V(ESD) Charged device model (CDM) | ±500V | ±1500 |
| RθJA （Junction-to-ambient thermal resistance） | 47°C/W | 45.6°C/W |
| RθJCtop （Junction-to-case (top) thermal resistance） | 60°C/W | 58.9°C/W |
| RθJB （Junction-to-board thermal resistance） | 20°C/W | 19°C/W |
| ψJT （Junction-to-top characterization parameter） | 1.5°C/W | 1.1°C/W |
| ψJB （ Junction-to-board characterization parameter） | 20°C/W | 19°C/W |
| RθJCbot （ Junction-to-case (bottom) thermal resistance） | 5.3°C/W | 4°C/W |
Part Number:UCC28070
Hello.
Bliss-san
I have additional questions.
Please look at the attached document.
Thank you.
(Please visit the site to view this file)
Part Number:LMR62421
Hi
My customer original use RT9293BGJ6 和ET5120A for LCM back light control but they meet LED flash issue.
so we promote LMR62421 EVM for them to test and without any issue.
But they need to controller the LED current to change the back light. so do you have an suggestion to add external circuit to meet this request?
BRs
Eric Lo
Part Number:TPS22990
Dear support member,
My customer used TPS22990.
I have a question.
(Question1)
What is the reason why the pad (red) is larger than the resist (green) for the (middle) part?
(Question2)
The shape of the resist (green) is only at the output pin.
What is the reason different from other pins?
Best regard.
Bob Lee.