LMR14030: LMR14030 issue

Roy wang

Part Number: LMR14030
Other Parts Discussed in Thread: TPS560430

Hello；

Please help to check the LMR14030 Issue.

1. The project：Ultrasonic gas meter

2. The LMR14030SDDAR has interference with the ultrasound acquisition data.
3. When the power is turned on, it will interfere with the ultrasonic data part, resulting in uploading data error.
4. If we use external MIC29302 test, will not find interference.
5. Gas meter usually upload data, the current is generally below 200mA.

over 6 years ago

0 Vental Mao over 6 years ago

TI__Expert 5745 points

pls upload your schematic. What's your frequency? When the load is 200mA, the IC will work in eco-mode, and the frequency will decrease which may disturb your updating data.

0 Roy wang over 6 years ago in reply to Vental Mao

Intellectual 775 points

Hello，

please check the schematic in the attachment.

0 Vental Mao over 6 years ago in reply to Roy wang

TI__Expert 5745 points

What's your input cap? Please add 20uF input cap. Ceramic cap is OK.

What's the purpose about the R34? If could , remove it.

Change the C26 to 4.7nF, slow down the start-up rate to decrease the interference

Change the L1 to 3uH, Cout to 180uF(ESR=11m ohm) to make the loop stable

0 Andy Chen over 6 years ago in reply to Roy wang

TI__Mastermind 27295 points

Hi

What's maximum load current of V3.3? if it's below 600mA, then pls try TPS560430 which is more easy to use and has fixed switching freq at light load.

0 Andy Chen over 6 years ago

TI__Mastermind 27295 points

Hi Roy,

It's will be set as Resolved if you have no more inquiry on this thread.

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LMR14030: LMR14030 issue