I am designing 480W Half-bridge DCDC converter using the LM5036. My input voltage range is a battery bank with a range between 122-90VDC. The output will be 12VDC with a full load efficiency of 93+% (is what I am trying to achieve). This is my first larger DCDC converter design, fyi.

Looking at the datasheet (http://www.ti.com/lit/ds/symlink/lm5036.pdf?src-supplier=Digi-Key) on page 42 is a reference design. I was hoping that someone could help me understand the input capacitor selection for the capacitive divider plus resistive divider before the primary fet's. From what I've read the resistive divider is two-fold, keeps the middle point voltage more accurate since the tolerance of resistors is mostly better than caps, and it also helps control the discharge of the caps. I was hoping you could show mathematically how those values got chosen?

Cheers,

Will

↧

BQ25121A: Battery charging IC with LDO with 3.3V output

October 24, 2019, 2:32 pm

≫ Next: BQ2000EVM: Configuration Inquiry

≪ Previous: LM5036: Input Capacitor Selection Help?

Part Number: BQ25121A

I am looking for a battery charging IC with an LDO similar to the BQ25121A.

I have a 3.7V Li-Ion battery that needs to be recharged at 4.2V at 250mA
The IC needs to support USB charging and powering the host system at the same time
Will be delivering power to a MSP430FR2476 which runs at 3.3V
Preferably provides some information on the state of the battery such as level of charge remaining
Does not use the BGA package.

Basically, the BQ25121A can provide what we need, except it comes in a BGA package which I would prefer not to use.

Thank you

↧

BQ2000EVM: Configuration Inquiry

October 24, 2019, 2:38 pm

≫ Next: CSD17303Q5: Invalid Device $CDNENCSTART error when trying to make new macro

≪ Previous: BQ25121A: Battery charging IC with LDO with 3.3V output

Part Number: BQ2000EVM

Hi Team,

My Customer is working with BQ2000EVM, he found that red LED permanently ON. When he removed the Li-Ion pack, the red LED still remains permanently ON. Is this correct? Because in datasheet it says that when no battery detected, the red LED should be OFF.

And another one is datasheet states that the system detects the battery chemistry automatically and proceeds with charging. So, could we connect jumpers at J5 (e.g. 1 jumper at 8 for 8 NiMH batteries) and J6 (e.g. 1 jumper at 3 for 3 Li-Ion batteries) simultaneously so that they can connect whichever battery we want to charge?

Regards,

_Renan

↧

CSD17303Q5: Invalid Device $CDNENCSTART error when trying to make new macro

October 24, 2019, 3:06 pm

≫ Next: BQ27510-G3: IO Question

≪ Previous: BQ2000EVM: Configuration Inquiry

Part Number: CSD17303Q5

I downloaded the Pspice model from the TI website and I'm trying to add it into TINA TI, but I get the above error. How can I fix this?

↧

BQ27510-G3: IO Question

October 24, 2019, 3:31 pm

≫ Next: LMZM33603: Maximum Output Capacitance

≪ Previous: CSD17303Q5: Invalid Device $CDNENCSTART error when trying to make new macro

Part Number: BQ27510-G3

Hi Team,

My customer has a quick technical question on the BQ27510-G3 fuel gauge that I want to confirm with you.

During their power off state, the fuel gauge will still be receiving its power from the battery. The 3.3V to the MCU will be off, so the GPOUT and I2C signals (SCL/SDA) will be floating. I don't foresee a problem as GPOUT is open-drain and I2C is an open-drain architecture as noted in the spec.

Do you see any concerns on those 3 IOs when they're floating but the fuel gauge has power?

Thanks,
Mitchell

↧

LMZM33603: Maximum Output Capacitance

October 24, 2019, 5:05 pm

≫ Next: LM5050MK-1EVAL: Reverse Polarity on Evaluation board

≪ Previous: BQ27510-G3: IO Question

Part Number: LMZM33603

I am using LMZM33603 to generate a 9V DC rail from a 12V-24V input. Table 1 says the required Cout max for a 9V Vout is 110 uF. My 9V rail provides power to a processor board that has over 800 uF of capacitance on that rail. What will the effect be on the LMZM33603 if the output capacitance is way more than the recommended max from table 1?

What are my options for providing a 9V rail to this processor board? Should I consider a different DC/DC converter?

↧

LM5050MK-1EVAL: Reverse Polarity on Evaluation board

October 24, 2019, 4:29 pm

≫ Next: UCC21530: Pspice simulation error

≪ Previous: LMZM33603: Maximum Output Capacitance

Part Number: LM5050MK-1EVAL

I have just received the LM5050MK-1Eval board we were considering using the LM5050 for reverse polarity protection in one of our designs. Prior to using the evaluation board on our unit I have connected it to an independent power supply. It is currently providing 7V with a current limit of .2A. When I reverse the polarity on the input instead of blocking the voltage it just becomes a short on the input. From my understanding I thought the evaluation board would act like an shcotky where it just blocks all negative voltage without becoming a short.

↧

UCC21530: Pspice simulation error

October 24, 2019, 6:36 pm

≫ Next: LM5145: EN/UVLO is pulled low by LM5145

≪ Previous: LM5050MK-1EVAL: Reverse Polarity on Evaluation board

Part Number: UCC21530

I am trying to simulate the programmable dead time of the UCC21530 SiC gate driver on PSPICE.

When I simulate the driver I get the following error:

ERROR(ORPSIM-15143): Voltage source and/or inductor loop involving X_U1.V_V13. You may break the loop by adding a series resistance

I tried to add a resistor t pin 13 as the error suggested but that didn't work.

Is it A design flaw, or a model flaw? Does anyone know how to fix it?

A Quick reply would be awesome, Thanks.

↧

LM5145: EN/UVLO is pulled low by LM5145

October 24, 2019, 6:42 pm

≫ Next: TLC59116: About Voltage drop on LED output channel

≪ Previous: UCC21530: Pspice simulation error

Part Number: LM5145

Hi experts,

Our design want to use UVLO function of LM5145. So, Ruv1 is 232K and Ruv2 is 9.1K in our design. At first, LM5145 work normally. After a while, LM5145 can not work beacuse the EN/UVLO is pulled below 1.2V by LM5145. Do you know why?

Best Regards

Li Yishan

↧

TLC59116: About Voltage drop on LED output channel

October 24, 2019, 6:45 pm

≫ Next: LP8732-Q1: LP8732xx suffix List

≪ Previous: LM5145: EN/UVLO is pulled low by LM5145

Part Number: TLC59116

Hello,

Regarding to voltage drop on TLC59116, my customer is asking some question.

(Question)

What is the voltage drop on LED output channel?

For example, my customer will use 4 LEDs in each output channel.

Total LED output voltage is 14V(3.5V(Vf) x 4), channel output current is 10mA and output supply is 15V.

In this case, is there any problem?

Also can it output with full 17V on each output channel?

Do we need to consider the voltage drop by FET on resistor (Ron)?

Regards,

Tao_2199

↧

LP8732-Q1: LP8732xx suffix List

October 24, 2019, 7:27 pm

≫ Next: BQ24292I: Check bq24092 datasheet block diagram

≪ Previous: TLC59116: About Voltage drop on LED output channel

Part Number: LP8732-Q1

Hi,

LP8732xx has several suffix.

Could you provide the list mentioned all suffix and difference?

Best Regards,
Kuramochi

↧

BQ24292I: Check bq24092 datasheet block diagram

October 24, 2019, 7:35 pm

≫ Next: TPS40322: Remote Sense

≪ Previous: LP8732-Q1: LP8732xx suffix List

Part Number: BQ24092

I am using bq24092.
Currently, I am confirming the operation of TS and temperature protection by referring to bq24092.pdf.

I have a question about the block diagram on p.15.
Does the attached image part exist in bq24092?

If yes, the list of parameters associated with the two blocks is as follows?:

"Disable Sink Current" => VTS-60℃, VTS-45℃
"Cold Temperature Sink Current" => VTS-10℃, VTS-0℃

↧

TPS40322: Remote Sense

October 24, 2019, 7:39 pm

≫ Next: CSD25481F4: Asking CSD25481F4 reliability report

≪ Previous: BQ24292I: Check bq24092 datasheet block diagram

Part Number: TPS40322

Hi E2E,

Could you kindly let us know how to calculate the resistor of remote sense? Is it simply Low-Pass filter?

If the resistor is too large, maybe 200~300k ohm (wrong component on PCB), Does VOUT will reach for OVP because RemSNS+/- sense nothing?

If we don't need the remote sense function. how to modify the circuit? floating or connect to GND?

↧

CSD25481F4: Asking CSD25481F4 reliability report

October 24, 2019, 8:24 pm

≫ Next: TPS92630-Q1: TPS92630Q1 Fault pin voltage and current capability

≪ Previous: TPS40322: Remote Sense

Part Number: CSD25481F4

Do you have CSD25481F4 reliability report? I'm not able to get from Customer support center. Thanks.

↧

TPS92630-Q1: TPS92630Q1 Fault pin voltage and current capability

October 24, 2019, 8:29 pm

≫ Next: TPS2819: Burning issue

≪ Previous: CSD25481F4: Asking CSD25481F4 reliability report

Part Number: TPS92630-Q1

Dear TI'S:
Custom use tps92630q1 as turn lighting , schematic as follow.PIN fault and fault_s connect together to drive a BJT(BCP56) .
R40=1K C18=C19=103K. Test point is for BCM detect.

(Please visit the site to view this file)

1, I want to know the design is ok? Cause tps92630q1 have weak pullup current.

2. Custom found 2 bad pcs of tps92630q1, and the fault pin voltage turn to 3.7V, however ,the good pcs of tps92630q1 is 3.2V. the waveform see fig2.
The left is good pcs, the right is bad one. The top is Test point waveform, and the bottom is for fault waveform.

3.We have double check the BJT is ok, and the abnormal phenomenon follow the bad IC. Custom need FA analysis ,but I’m not sure the design is suitable or need to be optimized.
thanks

↧

Latest Images