24V PDB

Owned by Rayyan Mahmood
Last updated: May 27, 2024 by Dale Huang
3 min read

Owner: @Dale Huang

Webench designs:

  • https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=13B65E135B7896D1 - 5A output, efficiency: 97.4%, from webech bom cost $5.05, 15uH inductor

    • Picked this one LM76005QRNPRQ1 IC.

    • Data sheet:

    • Eval Board:

  • https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=34026DE47E09A05F

  • https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=5BC93D3FF432BFA0

 

Inductor selection:

Component

Inductance (uH)

Isat (A)

Size (mm x mm)

Component

Inductance (uH)

Isat (A)

Size (mm x mm)

XAL1010-153MEB (Original out of stock)

15

15.5

11.3 x 10

IHLP6767GZER150M11

15

12

17.15 x 17.15

PM4343.153NLT

15

12.5

14.00 x 12.80

PA4342.153NLT

15

10

11.50 x 10.30

PA4344.153ANLT

15

16

17.80 x 16.90

74435571500

15

14

18.30 x 18.20

74435571500 seems to be the best performing option when it comes to current vs inductance. However the drawback is mainly the size of the inductor.

 

image-20240520-034948.png
Inductance formula

Inductance and ripple current can be found based on these equations in the IC’s data sheet. 15 uH is recommended according to Webench.

Input capacitor selection:

GRM31CC72A475ME11L: 4.7 uF (100 VDC, +/- 20%)

C2012X7S2A474K125AB: 470 nF (100 VDC, +/- 10%)

Output capacitor selection:

Calculations:

 

Development Milestones:

Select a design from WeBench
In stock IC
Has at least 1 visual layout reference (pref 2)
WeBench, datasheet, eval board, dev board, online reference
Datasheet has layout guidelines
Read through the datasheet, try to get a general overview of the features/function. Looks for any exceptions or caveats.
Make sure the basic inputs, outputs are supported in the datasheet
Order the stock risk components
Implement the design EXACTLY as it appears in WeBench
Individual design review
Group design review
Verify the circuit matches WeBench
Verify the circuit is consistent with the datasheet
Read through the datasheet for any caveats
Reformat the circuit with Rayyan to bring it to team schematic standards
Group design review to verify no electrical changes were made during the reformatting
Implement design review changes
Complete the placement of the board
Don’t worry about space constraints but the board should be generally tight
Refer to the datasheet and layout references
Refer to buck converter documentation below
Group design review to make sure the board is compliant with all referances
Work with Rayyan to implement stack up, power planes and polygons