TPS54331: SwitcherPro Desktop Design tool

Yassir Alamin

Prodigy 30 points

Part Number: TPS54331
Other Parts Discussed in Thread: SWITCHERPRO

Dear All,

We Used the SwitcherPro Desktop design tool to design a buck converter with below Spec:

Input volt min = 3.8 v Input volt Max = 5 v

Output volt = 3.1 v Iout Max = 1A

we toke the generated Schematic and complete the PCB design, then sent it to manufacturing and start testing as follow:

Input volt: 4.9 v ----> Output volt = 3.22 v

when the Input volt went below 4.7 v -----> The Output volt = floating 2.xx

*All these measurements have been done using the Multimeter

Below is a Schematic generated by the SwitcherPro Desktop

over 3 years ago

0 Young Zhao over 3 years ago

TI__Genius 9280 points

Hi，

There are 2 resistors (R6,R7) for adjustable VIN UVLO undervoltage lockout.

Based on your current config, the part needs to start to work around 4.5v and lockout around 3.5v. Below is some comments for your reference.

1. Please optimize these 2 resistor value based on your need. You can refer below equation1 and equation2 in datasheet .

2. Please add a 0.1uF capacitor close to VIN-GND.

3.Please add a larger Cout capacitor for better loop performance and smaller output voltage ripple .

0 Yassir Alamin over 3 years ago in reply to Young Zhao

Prodigy 30 points

Hi Young Zhao

thanks for your reply, actually, before I saw your reply I use the WEBENCH Power Designer with the same specification and the Generated schematic was totally different from the first one which generated by SwitcherPro, Now I am really confusing which tool should I depends on.