JFE2140: 参考JFE2140EVM,输入接GND时，输出会有三角波.

shengzhong zheng

Prodigy 10 points

Part Number: JFE2140
Other Parts Discussed in Thread: TINA-TI

原理图如下，和JFE2140EVM不同之处，R204,R205 3K 1%， R210 8.2K 1%，R208 1K 1%, 目前实际贴的电阻都为1%，

不接输入/接GND的情况下，会输出如下波形：但通过Tina-TI仿真是正常的，暂时找不到哪里问题，请帮指导调试方向

10 months ago

0 Chris Featherstone 10 months ago

TI__Mastermind 21910 points

Hello,

We are currently looking into this question.

Best Regards,

Chris Featherstone

+1 Chris Featherstone 10 months ago

TI__Mastermind 21910 points

Hello,

I believe the circuit is unstable. I have performed a step response with no feedback capacitor and observe ringing on the output.

By placing a compensation capacitor in the feedback beta network the ringing and overshoot are eliminated.

JFE2140.TSC

Best Regards,

Chris Featherstone

0 shengzhong zheng 10 months ago in reply to Chris Featherstone

Prodigy 10 points

这个问题好了，非常感谢。另外现在输出有20mv左右的50hz频率的干扰。这个需要怎么定位，目前是用的稳压电源给到LM27762DSS后再输出+/-5V.

0 shengzhong zheng 10 months ago in reply to shengzhong zheng

Prodigy 10 points

不好意思，发现这个是50HZ工频干扰是测量探头线这边引入，不过目前还是会输出如下波形。

0 Chris Featherstone 10 months ago in reply to shengzhong zheng

TI__Mastermind 21910 points

Hello,

I am unable to translate the question into English to assist.

Best Regards,

Chris Featherstone

0 Chris Featherstone 10 months ago in reply to shengzhong zheng

TI__Mastermind 21910 points

Hello,

I was able to translate the last post. The circuit is sensitive to power supply noise and this can be filtered out with a large decoupling capacitor on the power supply line. The trade off will be startup time in order for the capacitor to fully charge. Are you still seeing this issue?

Best Regards,

Chris Featherstone

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JFE2140: 参考JFE2140EVM,输入接GND时，输出会有三角波.