TIDA-00637 GFCI circuit

Victor Chen_HK

Expert 5130 points

Other Parts Discussed in Thread: LM7322

Hello,

Could anyone explain how does the GFCI detection circuit works?

in the schematic below, what is the range of AVCC that is supply to the LM7322(U3A in the schematic) http://www.ti.com/lit/df/tidrjj0a/tidrjj0a.pdf
What is the turn-ration of the current sense CT and GFCI CT?
In the user guide, there is an example of detection in seesion 8.3. Why 10mA is considered as false triggering and 15mA is considered as solid triggering? If the current sense CT is 2000:1 as which is described on page 18 session of session 5.2, 15mA/2000*13Ohm only creates 0.1mV AVCC. The op-amp can't even be in normal operation.

over 8 years ago

0 Jace H over 8 years ago

TI__Guru 56685 points

Moving to LM7322 forum for they own this design.

0 Victor Chen_HK over 8 years ago in reply to Jace H

TI__Expert 5130 points

Hi JH,

The questions are about the TI design instead of the op-amp.
I guess PA forum is not the proper place to go.

Thanks and best regards,
Victor

0 Jace H over 8 years ago in reply to Victor Chen_HK

TI__Guru 56685 points

Victor,

This TID was made by the team supporting LM3722 (I think). MSP430 did not create this design and know nothing about its inner workings. With some of these TIDs, its hard to distinguish who made them and thus who supports them, especially when they incorporate parts from several product lines. TIDA's come from the Analog side of the House, while TIDM comes from MCU.

If this is not the correct Analog forum for this design, the Forum Owners here will have a better idea of where it needs to go.

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TIDA-00637 GFCI circuit