Opto Isolated Gate Driver compatible with Teensy 4.1?

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Marathonman

Marathonman

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Hello everyone,

I am currently working on an Duel H bridge solar tracker motor drive board. this is going to be a one stop solution having all components on one board with 12 and 24 volt capability @ 15a and 8a peak respectively. i wanted to use the Teensy 4.1 until i hit a tissy fight between the Teensy and the Texas Instruments UCC23514S.

according to the spec sheet on the Teensy it recommends a 4 ma max.
according to the Texas Instruments the UCC23514S has an recommended operating current of 7ma to 16ma.

Quote from Spec sheet;

"The forward voltage drop across the e-diode is 2.1V (typ). An external resistor should be used to limit the forward current. The recommended range for the forward current is 7mA to 16mA. When IF exceeds the threshold current IFLH(2.8mA typ.) a high frequency signal is transmitted across the isolation barrier through the high voltage SiO2 capacitors."

So i guess my question is do i dump the Teensy and get a piece of crap Arduino to hook up to the driver.
any solution would be appreciated.

Thanks in advance,
Marathonman
 
Hello,

Connect the Anode via a current limiting resistor to the 3.3V rail and the cathode to ground thru a N channel mosfet. Then drive the mosfet with the Teensy. Also just to be safe put a pulldown resistor on the mosfet gate.

Regards
 
I can't do it like that. if you refer to the original post i stated that the Teensy ONLY puts out 4 ma and the driver requires 7 to 16 ma so it is not going to happen that way sorry.

well i just answered my own question. apparently i must have missed it. the spec sheet says to use a driver buffer between the Teensy and the transistor driver in low voltage situations. i did not want to do this but considering the limitations of the Teensy output i don't think i really have a choice. only if i choose to use another driver so hear goes the search again.
Regards,
Marathonman
 
Hello

I don't think you understood my answer, the current will come from the 3.3V supply rail via the resistor and the mosfet will switch it to ground, you will only use microamps of current from the teensy to drive the mosfet.
 
Closest example I can find at the moment.

Opto-high-side.png
 
Will you be driving the MOSFET with just an on / off signal, or will you be using PWM to control motor speed?
 
Yes i figured that out when i was running the question through my mind before sleep Inventor. thanks for the replay.

Kris'
I will be PWM to control motor speed with soft start. but i am at a toss up between IR2104 and a full bridge like the MIC4606-2YTS-TR which has two PWM, one for A half and B half.
my concern is that most IC chip manufactures want the chip as close to the bridge as possible with with the MIC4606-2YTS-TR it is only possible in my case to get close to one side. the other is 1 1/2 inches away.

with the IR2104 i can get right up on each bridge half but i like the MIC4606-2YTS-TR very much so i am not sure which way to go. the Teensy will be mounted right on the board.

and thanks for the reply.

Regards,
Marathonman
 
Oh by the way, the tracker will not be using LDR's. i found a guy on line that came up with a program that actually tracks the daily and seasonal motions of the sun then converted it into the Arduino program. the reason he did this is because one of his trackers would point to a bright cloud while the other was at the sun. so to alleviate this the program tracks the actual movements per time of day and season. i down loaded it and will change to suit my needs.

Regards,
Marathonman
 
Although the half bridge driver from Skyworks Solutions seems to be good also. the SI8274 has a single PWM input that controls the half bridge. so by using this I will have Four PWM to the Teensy plus the En pins for fault and shutdown at night. this is of course for two full bridges for N/S and E/W motors. Teensy will then mount directly to the board. I then hope to incorporate remote monitoring of some sort.
Regards,
Marathonman
 
Changed my mind and decided to go with Skyworks. never heard of Skyworks until i searched for isolated gate drivers. seams they bought part of silcon labs i think.
the SI8274 is great having just one PWM controlling half bridge. plus i get right up to the half bridge with this chip.
Her is what i am working with. Digital lines are longer but i think it will be OK.
Any concerns please pipe in.

SI8274 PWM.PNG

Regards,
Marathonman
 
I have a quick question. how would i go about getting wifi on a Teensy to connect to cell phone to monitor with Android App. i do not want it connected to the net just on the property connection. the App will be password protected.
also just how far will bluetooth go for connection purposes?
any such comments are welcome.

Regards,
Marathonman
 
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