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TL783 - simulation model for SPICE / TINA-TI ?

Dale Mahalko
Prodigy 20 points
Other Parts Discussed in Thread: TL783, TINA-TI

Is there an official SPICE simulation model available from TI, for the TL783?

I looked in TI's own TINA-TI, but it's apparently not included in the standard library.

.

I can not find *783* or TL783 in the TINA parts library from here:

TI - SPICE Model Resources

http://www.ti.com/adc/docs/midlevel.tsp?contentId=31690

.

The only thing I can find is this website:

http://www.rocklinger.se/Elektronik/Simulering/LT_Spice_models_en.html

.

I am not a SPICE expert so I have no way of knowing if this model is truly accurate:

http://www.rocklinger.se/Elektronik/Simulering/models/tl783.inc

.

* TL783C voltage regulator "macromodel"
* subcircuit
*created using Parts release 5.3 on 04/08/93
* at 15:09
* PARTS is a MicroSim product.
*
* connections: input
* | adjustment pin
* | | output
* | | |
.SUBCKT TL783C IN ADJ OUT
*
* POSITIVE ADJUSTABLE VOLTAGE REGULATOR
JADJ IN ADJ ADJ JADJMOD
VREF 4 ADJ 1.27
DBK IN 13 DMOD
*
* ZERO OF RIPPLE REJECTION
CBC 13 15 8e-010
RBC 15 5 1000
QPASS 13 5 OUT QPASSMOD
RB1 7 6 1
RB2 6 5 85.21
* CURRENT LIMITING
DSC 6 11 DMOD
ESC 11 OUT VALUE={1.96-0.01057*V(6,5)*V(13,5)}
*
* FOLDBACK CURRENT
DFB 6 12 DMOD
EFB 12 OUT VALUE={2.326-.03221*V(13,5)+0.0001421*V(13,5)*V(13,5)-0.02*V(13,5)*V(6,5)}
EB 7 OUT 8 OUT 8.069
*
* ZERO OF OUTPUT IMPEDANCE
RP 9 8 100
CPZ 10 OUT 1.989e-006
DPU 10 OUT DMOD
RZ 8 10 0.1
EP 9 OUT 4 OUT 100
RI OUT 4 100MEG
.MODEL QPASSMOD NPN (IS=30F BF=50 VAF=94.64 NF=7.604)
.MODEL JADJMOD NJF (BETA=8.3e-005 VTO=-1)
.MODEL DMOD D (IS=30F N=7.604)
.ENDS


  • 0
    TI__Guru**** 166116 points

    Hello Dale,

    TI does not have a model for the TL783. I do not know if the attached model is accurate or not.

    I can review if the TL783 is a good fit for your application.
    What is the input voltage range (min,max)?
    What is the desired output voltage?
    What is the output current range (min,max)?

    Regards,
    Ron Michallick

     

     

  • 0 in reply to Ron Michallick
    Prodigy 20 points

    I am looking for about 120-125 volts regulated output, with up to 20 amps current capacity, from 120v AC line power.

    It looks like Figure 20 of the TL783 application note accomplishes what I want to do.

    Building it in TINA-TI, using this "unknown reliability" TL783 model I found here and generic !PNP !NPN transistor models, figure 20 can sustain up to 6 amps continuous in TINA's simulations and remain stable. Shorting it in TINA causes an output spike at startup that is immediately suppressed by the current limiting transistor design of Figure 20..

    I am not yet a fully knowledgeable electronic circuit designer, so I don't know how to increase the output current just by adding a few more transistors.

    But I see it does work in TINA-TI to just consider Figure 20 a module, and parallelize a bunch of Fig 20 modules together to increase output current., with output diodes separating each regulator circuit.

    Attached to this post is an 8-way parallel group TINA model of Figure 20. It starts up and runs stably on the TINA oscilloscope, with 6.25 ohm load / 20 amps output at about 125 volts DC.

    Actually it runs stable in TINA with 3.125 ohm load / 40 amps @ 125 volts DC, but I want overhead in load handling capability since I can't be certain how accurate this TINA model is.

    Also, distributing the thermal load across multiple parallel power transistors will reduce the heatsink / fan cooling requirements for each module.

    TL783 - test circuit - working fig 20 - 8-way.TSC
  • 0 in reply to Dale Mahalko
    TI__Guru**** 166116 points

    Dale,

    The eight sections will not share current current load well because each regulator will run at a slightly different voltage. I suggest using a single TL783 and expanding the NPN output (add NPN in parallel with small emitter resistors for current balance). There also needs to be protection to ensure the TL783 never sees more than 125V under any circumstance. I added a zener diodes to help with that.

    At 20 amp load, the transistors will need to dissipate about 1000W of power (50V * 20Amp). So a large heat sink with fans will be required.
    The whole circuit is electrically "hot" from the input line voltage and no node is safe to touch. Be sure to add a fuse to the input line.

    The high voltage, high power and having no isolation from the line makes this a dangerous project. I recommend not building this project.

    Regards,
    Ron Michallick