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TPSI3050-Q1: Designing with TPSI3050-Q1

Sv
Intellectual 635 points

Part Number: TPSI3050-Q1
Other Parts Discussed in Thread: TPSI3050, TPSI3052, TPSI3100, TPSI3052A

Tool/software:

Hello Team,
We are using the IC TPSI3050 in one of our products.
Attached is the schematic of the same.

Can you please review the same?.

The device is working in 2-wire mode.

The VSSP is connected to the CGND (Ground of the power supply).

The signal IN_H4 is a 12V signal and is completely isolated from the CGND.

Our device consists of almost 300 such signals.

For testing these devices, we have made a test jig
In the test jig, we have given a 5V at the IN_H4 pin of the device.
This 5V is taken from an AC-DC power adapter.
The GND at the DC side (5V side) is connected to the Earth pin at the AC side.

Our device is supplied with a 12V AC to DC adapter and the CGND (GND at the +12V side) is also connected to the AC earth.

So ultimately, both the signals at either side of the TPSI3050 is referring to the same GND.
What behavior can we expect in this situation?.

is there any problem if there is no isolation between the supplied at VSSP or VVDP and VSSS.

Looking for your reply

  • 0
    TI__Expert 8971 points

    Hello Sv,

    Thanks for reaching out to our team on E2E.

    There is no problem for our device if primary and secondary grounds are the same.

    I recommend adding 10 nF 0402 capacitor as close as possible to IC input (pins 3 and 4) as well as a 10 uF 1206 input capacitor (this does not need to be super close).

    What emissions (EMC/EMI) requirement does your product need to pass and how many TPSI3050s per product? This will affect further component recommendations. I am guessing some form of CISPR25 if you are asking about -Q1.

    Best regards, 
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden Chen,
    Thank you for your reply.

    Tilden Chen said:
    I recommend adding 10 nF 0402 capacitor as close as possible to IC input (pins 3 and 4) as well as a 10 uF 1206 input capacitor (this does not need to be super close).

    OK, we have added in the schematic.

    Tilden Chen said:
    What emissions (EMC/EMI) requirement does your product need to pass and how many TPSI3050s per product? This will affect further component recommendations. I am guessing some form of CISPR25 if you are asking about -Q1.

    We have almost 50 TPSI3050 in a single product.

    We need the device need to be CE Certified. For CE,  we will do conducted emission, conducted immunity, radiated emission and radiated immunity tests.

     Will there be any changes needed in the BoM if we are going for CE?.

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply.

    Yes we will need additional components for emissions, my team is working on finalizing our emissions recommendations for TPSI305x. I tried to look up emissions requirement for CE certification, looks like CISPR 32. Can you help confirm if this is true and whether this is Class A or Class B?

    Also, how many TPSI3050 devices need to be powered-on simultaneously during emissions test?

    Best regards, 
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden Chen,
    Thank you for your reply.

    Tilden Chen said:
    looks like CISPR 32

    Yes. 

    Tilden Chen said:
    whether this is Class A or Class B?

    The device will be Class B

    Tilden Chen said:
    Also, how many TPSI3050 devices need to be powered-on simultaneously during emissions test?

    All 50 TPSI3050 will be turned on while testing.

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply.

    For full transparency, my team is working on finalizing our emissions solution and should have results by end of the month. What is your project timeline? Hoping you can finalize layout after we have results.

    Best regards, 
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Team,
    Thank you for the reply.

    Tilden Chen said:
    What is your project timeline? Hoping you can finalize layout after we have results.

    We have completed the PCB design and is under review.

    Tilden Chen said:
    results by end of the month

    Is there any chance we can get this by end of next week?.

    Please note our device falls into Class A category.

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply and sorry for my delayed response.

    I am working on a board to finalize to confirm our emissions recommendations, we want to confirm our theories before recommending to customers. The PCB design will be complete end of this week, 1 week turnaround, then will be testing end of October.

    Overall, the TPSI305x has had challenges with emissions. We cannot pass Class A using 50 devices and no filtering components. My industrial radiated emissions testing with single TPSI3052 shows only 20 dBuV margin from Class A limit. 50 powered devices would need 34 dBuV margin. We have identified areas for improvement on our existing board so we are trying to quantify these improvements on the new board before we can make recommendation.

    For long term, our design team is also working to improve emissions on the second generation device, TPSI3100 with the improved emissions P/N under TPSI3100A. Expected to sample TPSI3100A in January 2025, then design team plans to rework TPSI3052 into TPSI3052A.

    Best regards, 
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden,
    Thank you for your reply.

    For Class A, the limits are 50dBuV/m. Please correct me if I am wrong.

    Our product will have an EMC complaint enclosure and we expect our radiation will be less.

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for the update. Maybe we can try to replicate your enclosure in our setup to see the performance, do you have any more information on the enclosure?

    Best regards, 
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Team,
    Thank you for the reply.

    The part number of the enclosure is 24572-092

    Also, what is the switching frequency of the device?.

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply. Yes, the enclosure will help with radiation. I am assuming the enclosure is for conducted emissions. Do you need to test radiated emissions as well? 

    TPSI305x main operating frequency is around 80-90 MHz. 

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden,
    Sorry for replaying late.

    Can you please test radiated emission as well?.
    We need both conducted immunity, conducted emission, Radiated emission and radiated immunity tests for the actual compliance test.

  • 0 in reply to Sv
    Intellectual 635 points

    hello Team,
    Awaiting your reply

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply. 

    Yes, I will be taking a look at how our device performs on layout-optimized board in conducted and radiated emissions. The emissions board I was working on got delayed, but just sent out the board files to contract manufacturer. Should be getting the board in about a week and will check out the emissions performance ASAP.

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden,
    Thank you for your reply.
    Can you please confirm whether the emissions from the device are the same or different when operating in 2-wire mode and 3-wire mode with the device enabled?

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    Thanks for your reply.

    The device will have different emissions in 2-wire and 3-wire mode as the device transfers different amounts of power. I would expect 2-wire mode to have lower emissions due to lower power transfer. EN state did not affect emissions much in our internal testing.

  • 0 in reply to Tilden Chen
    Intellectual 635 points

    Hello Tilden,
    Thank you for your reply.

    In 2 wire mode, we will be giving 12V to the EN pin, the VDDP pin will get charged, and the power is transferred to the isolated secondary side and to the VDRV pin.
    In 3 wire mode. we will give a 5V in the VDDP and the power is transferred to the isolated side, when enabled we will get voltage at VDRV pin.

    In both the cases power transfer is the same.
    Please correct me if we are wrong.

    Also, can you please share the conducted and radiated emission results?.

  • 0 in reply to Sv
    Intellectual 635 points

    Hello Tilden,
    Do you have the test reports available for me?

  • 0 in reply to Sv
    TI__Expert 8971 points

    Hello Sv,

    I have attached emissions results of our TPSI3xxx devices in industrial emissions setup. These were taken on boards that do not have EMI-optimized layouts.

    There were some delays on getting the boards with EMI-optimized layouts, should be getting those boards in 2-3 weeks and will take emissions measurements on those as quickly as possible.

    TPSI3xxx Industrial Emissions.pdf