We have questions about TPS54540-Q1.
Vin=30V
Vout=5.5V
Iout=3.7A
Output noise increases under the following conditions.
The above phenomenon can be seen with 1 out of 1,000.
frequency=DC~100kHz
temperature=-10℃
(Noise doesn't increase at 25℃ and 60℃)
(Abnormal device)
DC~50kHz
Low temperature : -65~75dB
Normal and high temperature : Under 80dB
Over 100kHz
Low temperature : Under 80dB
Normal and high temperature : Under 80dB
(Normal device)
DC~50kHz
Low temperature : Under 80dB
Normal and high temperature : Under 80dB
Over 100kHz
Low temperature : Under 80dB
Normal and high temperature : Under 80dB
We checked external circuit of TPS54540-Q1.
This is almost equivalent to curcuit of EVM.
We think that our circuit is no problem.
This pjenomenon doesn't occur when we change the IC from abnormal device to normal device.
About abnormal device,
Output noise doesn't improve when we change the external parts(register, capacitor, inductor).
Question 1.
Do you know the reason why noise increases at Low temperature and low frequency?
Question 2.
Does the output noise increase by external circuit design?
We have the data of circuit and waveform.
But we can't open these data in e2e.
Is it possible to use private e2e?
Best regards,
Takahiro Nishizawa
