TL3016: Zero-Crossing Detection using TLV3501 or TL3016

Muhammad Abdelraziq

Part Number: TL3016
Other Parts Discussed in Thread: TLV3501, TLV1872, TLV3601, TINA-TI

Tool/software:

Greetings,

I am making two PCBs to test two Zero-Crossing Detection (ZCD) circuits. The first will use the TLV3501 comparator, and the second will use the TL3016 one. I came across the PSPICE tool and wanted to simulate each case before making the PCBs. Here is my schematic for the circuit deploying the TLV3501 comparator:

I will use a current-sense transformer to measure a high-frequency current (~500 kHz). The output of the comparator will drive a synchronous rectifier.

Here is my output SHOWING THAT THE COMPARATOR IS NOT WORKING:

Could you please help me figure out why this simple circuit is not working as expected?

Looking forward to your help.

7 months ago

0 Muhammad Abdelraziq 7 months ago

Prodigy 20 points

Here is the output once I hide the input trace:

+1 Paul Grohe 7 months ago

TI__Guru 53996 points

Hello Muhammad,

Tie the shutdown (pin 3) to V- (pin 5).

The shutdown pin is referenced to the V- pin. Since you are using this is a split supply, you are applying the equivalent of +2.5V to the shutdown pin - which is in the middle of the logic thresholds. See section 7.4.1 of the datasheet.

If this interests you, we do have a new device that is specifically designed for split supplies, the TLV1872, which is designed for spit supplies and has separate output supplies, so you can define your own output VOH and VOL.

https://www.ti.com/product/TLV1872

0 Muhammad Abdelraziq 7 months ago in reply to Paul Grohe

Prodigy 20 points

Thank you! I switched to using TLV3601. I want less propagation delay, so I cannot use the TLV1872.

0 Muhammad Abdelraziq 7 months ago in reply to Paul Grohe

Prodigy 20 points

BTW... Does TI have a comparator similar to this Analog Devices comparator? I want to be able to have a unipolar square wave output rather than a bipolar square wave output...

LMK...

+1 HO SIU 7 months ago in reply to Muhammad Abdelraziq

TI__Expert 6340 points

Hi Muhammad,

Currently, we don't have a dual supply comparator that has the same propagation delay as the ADI device you posted.

There is still a way to do a zero-cross detection circuit using TLV3601. It could be done through a reference rail and AC coupling the input to the comparator as shown:

This method centers IN+ around VREF, such that the comparator can be powered by a single supply for the unipolar square wave.

Here is the simulation result:

Would this solution work for you? I've attached the TINA-TI file for this schematic.

TLV3601ZeroCross.TSC

0 Muhammad Abdelraziq 7 months ago in reply to HO SIU

Prodigy 20 points

Yes, this option works for me too! Thank you!

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TL3016: Zero-Crossing Detection using TLV3501 or TL3016