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Original question:

TPSI3052-Q1: Request for SIMetrix Model

TPSI3052-Q1: IC not behaving as expected at higher Temperature

Sweshwaran M
Prodigy 105 points
Part Number: TPSI3052-Q1
Other Parts Discussed in Thread: TPSI3052,

Tool/software:

Hi, 

I am using the simetrix model of TPSI3052 in my simulation which i got from "e2e.ti.com/.../tpsi3052-q1-request-for-simetrix-model"

I did notice that when simulating this model at high temperature the output node 'DRV' declines to 0V, even when Enable line is pulled up throughout.

  

I need some help in understanding what this model behavior. Is this intended  or just a model issue?

  • 0
    TI__Expert 6346 points

    Hello Sweshwaran,

    Thanks for reaching out to our team on E2E. TPSI305x-Q1 power transfer varies across temperature, basically decreases as temperature goes up. It looks like in your simulation, the driver (VDRV) is hitting falling UVLO (VDDH_UV_F) and shutting off.

    This is expected if you have:

    1. A resistive load with EN with high time exceeding device's power transfer capability
      OR
    2. Capacitive load with switching frequency exceeding the device's power transfer capability


    Would you please share the simulation circuit to confirm?

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Prodigy 105 points

    Hi Chen,

    I have connected a large resistive (around 5k ohm) load across DRV and VSSS. Please refer to the schematic attached. 

  • 0 in reply to Sweshwaran M
    TI__Expert 6346 points

    Hello Sweshwaran,

    Thanks for your reply. Try increasing that pulldown resistor to 100k ohm and removing R3 unless you are intentionally slowing gate turn-on. 10 nF gate capacitance seems large, does the MOSFET/IGBT have 150 nC total gate charge? 

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Prodigy 105 points

    Hi Chen,

    Increased that pulldown resistor to 100kohm & it resolved my issue. What exactly is the reason behind it?     

    My design requires deliberately slowed turn ON and Yes it requires to pump almost 150nC of gate charge. 

    Thanks & Regards,

    Sweshwaran M 

  • 0 in reply to Sweshwaran M
    Prodigy 105 points

    Hi Chen, 

    Just made an Observation, that it works fine till 100deg C, but once i do increase the temperature beyond 100deg C, the output DRV node falls. Attaching a screenshot here, Please note that Pull down resistor is removed** for this simulation. (Same observation with a pull down of 300kohm) 

  • 0 in reply to Sweshwaran M
    TI__Expert 6346 points

    Hello Sweshwaran,

    Thanks for your reply. We are taking a look into the simulation models (I'm also seeing this in PSPICE). I don't think this is real behavior because without the pulldown resistor there should be no path for the 10 nF capacitor to discharge. The gate resistor should only slow down the turn on, but the load voltage should eventually come up. Will get back to you when we have a solution.

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    TI__Expert 6346 points

    Hello Sweshwaran,

    We will try to set this up in the lab and force temperature to prove that this behavior would not happen on the silicon. Will get back to you within a few days.

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    TI__Expert 6346 points

    Hello Sweshwaran,

    Sorry for the delay here, there was some trouble coordinating equipment to setup this test. Please see attached for TPSI3052-Q1 turn on at 105°C, we don't expect the gate voltage to decay after time at higher temperatures because there is no discharge path until EN goes low regardless of temperature.

    Best regards,
    Tilden Chen

    Solid State Relays | Applications Engineer

  • 0 in reply to Tilden Chen
    Prodigy 105 points

    This must mean that my observation with Simetrix model must be of some model issue. 

    Anyway, this answers my question.

    Thank you