WEBENCH® Tools/LM3405: LM3405AXMKX/NOPB----We are not able to generate design form webench tool

Shubham patil

Intellectual 520 points

Part Number: LM3405

Tool/software: WEBENCH® Design Tools

Hello Team ,

We are planing to Use LM3405AXMKX/NOPB as IR Buck but we are not able to generate the design for this

Below are operating condition :

1.No of IR LED : 2

2.IR LED Forward Voltage : Min 1.2V and MAX 1.7V

3.Current Setting : 1A or 500mA

4. Buck Input Voltage : 3V3

Please help to generate this design .

Thanks ,

Shubham

over 4 years ago

0 Irwin Nederbragt over 4 years ago

TI__Mastermind 28655 points

Hello Shubham,

I will look at this design tomorrow. How are you going to drive two LEDs that have a forward voltage maximum of 1.7V with 3.3V input? Are they in parallel? This is a buck converter and does need some headroom.

Best Regards,

0 Shubham patil over 4 years ago in reply to Irwin Nederbragt

Intellectual 520 points

Hello Irwin,

We are planing to use two LED in series.

With below two input voltage option

Option 1 : Input Voltage : 5V

Option 2 : Input Voltage : 3V3

We need the design for above two option .

Thanks,

Shubham

0 Irwin Nederbragt over 4 years ago in reply to Shubham patil

TI__Mastermind 28655 points

Hello Shubham,

I would start with AN-1590: www.ti.com/.../LM3405XEVAL

Rcs, R1, for 1A = 0.205 ohm

Rcs, R1, for 0.5A = 0.41 ohm

Note that the input to output voltage differential will be limited by Vcs, 0.205V, and 94% duty cycle, 85% absolute minimum.

Best Regards,

Power management

Power management forum

WEBENCH® Tools/LM3405: LM3405AXMKX/NOPB----We are not able to generate design form webench tool