Should the TE35 module emit a continous high-pitched whine?

I’ve started working with a new TE35 module recently (my first and only one), and have noticed ever since I started using it that it emits a very high-pitched whine while it’s powered up. The volume of the sound is not high, but it is noticeable within about three feet of the device. The whine is constant, and doesn’t vary with what’s displayed or whether the backlight is enabled or disabled.

Is this normal behavior for this module and/or this type of display?


This may sound stupid but do other people hear it?

@ Gus -

Yes. Two people (out of two test subjects) hear it. One has a slight hearing loss, so has to be about a foot closer to it to notice it. But both hear it.

It goes away as soon as power is removed, and returns as soon as power is applied.

Like Andre said, this is normal but it shouldn’t be very low that you barely hear it.

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It’s the backlight voltage boost circuit. It happens on my custom built display too. I’m not sure if it’s the capacitor or inductor.

It’s fairly high pitched so it’s more audible for the young.

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Thanks, all. Glad to know it’s normal. We will ignore it.