↧
LM5034: Will LM5034 work in fold-back mode when OCP if connecting RES pin to GND?
↧
BQ24250: Vrch operation
Part Number:BQ24250
With VBATREG = 4.3V. If we plug our device into an external power source (USB) with the battery voltage at ~4.2V, the BQ24250 indicates "Charge done" when register #1 is read, and charging cycle does not begin.
Is this because the battery voltage is above VBATREG - VRCH? (70 min-160mV max) This does not happen with a depleted battery.
If that is the case, is there a way for us to override this and initiate the charge cycle so that the battery charges up to VBATREG (4.3V)? We have observed that if we toggle B1 of register #2 high followed by low (charging disabled followed by charging enabled), that the charge cycle will begin. Is this behavior expected?
↧
↧
TPS2546: Is the behaviour of TPS2546 normal?
Part Number:TPS2546
Team,
Customer is testing TPS2546 in notebook system and got below waveforms.
1. When system in S0, CTRL1/2/3=111; When system in S5, CTRL1/2/3=011.
2. When system in S0, drive current 2.1A，there is no VBUS drop.
3. When system shut down, change from S0 to S5, CTRL1 change from 1 to 0, VBUS will drop to 0 and then back to 5V, is it normal?
4. When system in S5, drive current 2.1A, VBUS will drop to 0 and then back to 5V as well, is it normal?
Could you let me know where I can find the explanation in datasheet? Thanks.
Note: in below waveform, 抽载means drive current 2.1A, 关机means system shut down (change to S5)
↧
CSD18543Q3A: Rise Time compared to CSD18563Q5A
Part Number:CSD18543Q3A
Hi,
the datasheet states a rise time of 18ns at V_GS=10V and I_DS=12A for the CSD18543Q3A. This appears rather slow compared to the CSD18563Q5A with a rise time of 6.3ns at V_GS=10 and I_DS=18A.
Since the Gate Charge of the CSD18543 is smaller than the Gate Charge of the CSD18563 i would assume a shorter rise time.
Is the rise time of the 18543 really that high?
Regards
Jan
↧
BQ25703A: Vsys and Vbat was absent to root cause
Part Number:BQ25703A
Hi Sir,.
we pluged adapter into BQ25703A EVM and no battery connected , but Vsys and Vbat were 6V existed,
For another customized PCBA ,(2S1P 7.3V,2850mA)
that Vbus.VDDA(CELL_BATPRESZ) .Hi-Z, and CHRG_OK all are present,
why Vsys and Vbat was absent from this situation, how`s reason between to two boards difference ?
thanks
↧
↧
BQ27441-G1: Qmax drops too much
Part Number:BQ27441-G1
In my 1S2P battery pack Qmax drops with each discharge cycle and the cell voltage for 0 % SoC rises in small steps from 2.7 V for new cells to 3.3 V after a few cycles. The full charge capacity and the runtime of the device powered by the battery pack also drops continuously.
My parameters are:
designVoltage 3700, terminateVoltage 2500, reserveCapacity 200, designCapacity_mAh 6700, designEnergy 24790, taperRate 240 (=280 mA), dsgCurrentTh 700 (=95 mA), chgCurrentTh 700 (=95 mA), quitCurrent 1000 (=67 mA), simRate 0x219 (280 - 3350 mA), loadMode 3 (constant current, average of 14s)
I charge with up to 2 A and discharge with 5 W. My microcontroller stops discharging at 0 % SoC. I wait 2 h when full and 2 h when empty so that Qmax is recalculated.
Why do I 'loose' battery capacity?
↧
LM5115: Is there a LaPlace domain model available?
Part Number:LM5115
Dear E2E,
I've built an SSPR with this controller, and it works well. But the control loop bandwidth is quite low, only around 1 kHz. The device itself has a novel mix of voltage mode, VIN feed-forward and current mode control. Do you have a Laplace model for the power stage? I'm looking for something I could put into MathCAD, evaluate graphically, and then determine the gain and phase needed for the compensator.
Thanks,
Chris
↧
BQ25060: BQ25060 specification check
Part Number:BQ25060
Hi Sir,
If the EN pin is connect to ground the resistor connected to Iset will control the input current.
If i set the input current to 177mA. VIN has connected to USB.
When the output current is around 550mA, the charger IC will change to supplement mode and external PMOS will be turn on? It will supply the output current from input current and battery on the same time, right?
Thanks,
↧
TPS62203: TPS62203 Output high current is drawn around 130mA without load
Part Number:TPS62203
TPS62203 Output high current is drawn around 130mA without load
Application: Duracell alkaline battery of full voltage of 1.6 V x 4 no's is used as input with load current of 1mA to 100mA.
When used IC SW pin to GND pin the resistance is 15 to 30 Ohm in failed Regulator but output is 3.3V
Pl. suggest the reason why the current drawn is high.
↧
↧
WEBENCH® Tools/TPS40210: negative voltage to negative voltage switcher at 6A.
Part Number:TPS40210
Tool/software: WEBENCH® Design Tools
I am trying to design a -24V to -15V switcher that can deliver up to 6A. Years ago Peter James Miller provided a topology which used the TPS40210 to generate a similar design but didn't provide any insight on how to calculate the R's and C's.
Also Webench does not accept negative input or output voltages for the TPS40210.
↧
LM2937: Aluminum and Ceramic Capacitor in parallel for Output
Part Number:LM2937
The datasheet recommends that a Tantalum capacitor be used in parallel with an Aluminum cap for the output.
Can you use a ceramic capacitor instead?
↧
Normally ON powerFET
I need a normally ON power switch. High-ish voltage (200V) and current (50A total with parallel devices), and low ON resistance are main requirements. Seems that only IXYS makes any depletion mode power MOSFETs and they are very pricey. I understand GaN devices are inherently normally ON, but it appears the GaN parts from TI and others are using a cascode FET on all their devices to make them function as normally OFF devices for use in the typical power switching circuit. But, the datasheets don't exactly call this out, nor do the search tools and I got tired of looking. Does TI have any parts that meet this requirement or any plans for any? Or, do you know of any others besides IXYS?
↧
TPS65023: What is the LDO reverse leakage spec?
Part Number:TPS65023
The TPS65023 datasheet states:
"The LDOs also have reverse conduction prevention. This allows the possibility to connect external regulators in parallel in systems with a backup battery."
I need to know what the reverse leakage current of the VLDO1/VLDO2 outputs is when the TPS65023 is not powered (VCC = 0).
Thanks
↧
↧
UCC28063EVM-723: UCC28063
Part Number:UCC28063EVM-723
Hi,
This UCC28063EVM-723 requires 13V bias source. How do you propose to get the bias source for this design? should I put an ACDC module in parallel with the AC input? also, the Vcc rating for the part is 14 min 21 max. Why does the evm board only require 13V for biasing? Thank you
Bobb
↧
TPS7A4701-EP: Linear Voltage Regulator For RF Board
Part Number:TPS7A4701-EP
Hi everyone,
I would like to design a product which needs RF power circuitry.
Input is 24V. Firstly, I need to use DC-DC converter, then I'll add LDO to the output of converter. Output power is 15V and current is nearly 1A. My application is highly sensitive RF, also EMI is very important.
So that, please suggest me some DC-DC converters and RF sensitive LDOs.
Thanks!
↧
LMZ14203HEVAL: voltage output
Part Number:LMZ14203HEVAL
dialing down output close to 5v with a 6.81k ohm resistor on ref des. Rfbb. any other changes I should do?
↧
LM185-ADJ: 883 not marked on part
Part Number:LM185-ADJ
Hello
I have in front of me what looks like
national semi
LM185BH
date code 0917
But the MFR COC that I got with it reads LM185BH/883
Is it possible that this part is a LM185BH/883 but that national semi just didn't mark the 883 on the part?
Also, does anybody know if national semi even offered a LM185BH without the mil std 883 processing level?
Because if it wasn't, than regardless of whether this part in front of me is marked 883 or not, I would know that this is a LM185BH/883 since it couldn't be anything else.
thank you
Andrew
↧
↧
TPS53513: TPS53513 LC filter
Part Number:TPS53513
Dear Team,
How to check the requirement of “LC filter have fc<=1/10 of switching frequency of the DC/DC converter” for TPS53513RVER?
The switching frequency right now is 600kHz.
(Please visit the site to view this file)
BR
Kevin
↧
BQ25060: BQ25060 schematic review and question
Part Number:BQ25060
Hi Sir,
Could you help to review the schematic as attachment? Is there any suggestion?
Other questions need to your support as below:
1.If the temperature over 45°C, then back to normal temperature. What is the safety timer for BQ25060?
2.If the BQ25060 enter into safety timer protection, how to reset it? Could we pull high EN pin to reset it? or other suggest for reset safety timer protection?
Thanks.![]()
↧
TPS2549: Fast charge scheme recommendation
Part Number:TPS2549
Hi team,
The customer needs:
- Four channel fast charge, the maximum current is 2.1A;
- Supporting BC1.2 CDP and DCP;
- Cable loss compensation.
Now the scheme is LMR14030*4 and TPS2549*4. I have heard about the new TPS25840 and TPS25842, but it is a pity that the two devices can't support DCP.
Could you please recommend another cheaper scheme? Is there any new devices which will support the customer's need?
Thanks a lot.
↧