using optocoupler HPCL-3120 to drive MOS switch

[arr_baobao]

as tittle above, how do i do connection for the drive the mos switch by hpcl-3120. like which pin to the Gate of mos and drains, and what should i connect to the anode and cathode pins of the opto driver

 

[mister_rf]

See details in the datasheet:

**broken link removed**

 

[gdylp2004]

as tittle above, how do i do connection for the drive the mos switch by hpcl-3120. like which pin to the Gate of mos and drains, and what should i connect to the anode and cathode pins of the opto driver

If you are intending to drive a nMOS for a high side switch, you may want to try the configuration as attached. That is the design I've made for using a 3120 optocoupler to drive a nMOS high side switching using bootstrap technique learned from here: (https://www.fairchildsemi.com/an/AN/AN-6076.pdf)

The resistor must be placed in series with the photodiode to limit the current to the OEM's specified ampere range. It's value could be pre-determined by using the input voltage minus away the turn on voltage (forward voltage drop of the photodiode when conducting) and then divide by the current "permissable". That is, using V=IR, hence R=V/I = (Vin-Vf)/I = (Vin-1.5)/0.01

For example, if your Vin = 5V, then your R would be 350 ohms. Now you can try sub back R = 350 ohms into I=V/R equation and you'll see that even for whatsoever reason the Vf goes above its typical value to its max. value = 1.8V (as specified in datasheet, your current = I=V/R = (5-1.8)/350= ~9.142mA and that is still well safe above the min. limit rated current (7mA) for the photodiode to conduct.

 

[arr_baobao]

im using the optocoupler to drive the switches in 2 switches foward converter. for the cathode and anode , pin 2 and pin 3 in hpcl 3120 , is it we just connect to the function generator to supply the PWM into the hpcl 3120?

---------- Post added at 12:40 ---------- Previous post was at 12:38 ----------

If you are intending to drive a nMOS for a high side switch, you may want to try the configuration as attached. That is the design I've made for using a 3120 optocoupler to drive a nMOS high side switching using bootstrap technique learned from here: (https://www.fairchildsemi.com/an/AN/AN-6076.pdf)

The resistor must be placed in series with the photodiode to limit the current to the OEM's specified ampere range. It's value could be pre-determined by using the input voltage minus away the turn on voltage (forward voltage drop of the photodiode when conducting) and then divide by the current "permissable". That is, using V=IR, hence R=V/I = (Vin-Vf)/I = (Vin-1.5)/0.01

im using the optocoupler to drive the switches in 2 switches foward converter. for the cathode and anode , pin 2 and pin 3 in hpcl 3120 , is it we just connect to the function generator to supply the PWM into the hpcl 3120?

For example, if your Vin = 5V, then your R would be 350 ohms. Now you can try sub back R = 350 ohms into I=V/R equation and you'll see that even for whatsoever reason the Vf goes above its typical value to its max. value = 1.8V (as specified in datasheet, your current = I=V/R = (5-1.8)/350= ~9.142mA and that is still well safe above the min. limit rated current (7mA) for the photodiode to conduct.

im using the optocoupler to drive the switches in 2 switches foward converter. for the cathode and anode , pin 2 and pin 3 in hpcl 3120 , is it we just connect to the function generator to supply the PWM into the hpcl 3120?

 

[gdylp2004]

im using the optocoupler to drive the switches in 2 switches foward converter. for the cathode and anode , pin 2 and pin 3 in hpcl 3120 , is it we just connect to the function generator to supply the PWM into the hpcl 3120?

---------- Post added at 12:40 ---------- Previous post was at 12:38 ----------




im using the optocoupler to drive the switches in 2 switches foward converter. for the cathode and anode , pin 2 and pin 3 in hpcl 3120 , is it we just connect to the function generator to supply the PWM into the hpcl 3120?

As mentioned previously, the resistor to-be connected in series with the photodiode (doesnt matter with pin 2 or 3 because it is a series connection) would limit the current (coming from the PWM generator) to a safe limit as instructed by the manufacturer seen in the datasheet. To calculate the value of the resistor, please see my previous post.