Dear sir/madam,

we are planning to use Si8233BD-D-IS driver for one of our motor inverter project. in the datasheet , it is specified as High electromagnetic immunity in the key features. 

I want to know, this driver will protect against the overshoots( that may cause EMI) during switching transitions.

Also please provide the maximum active current values for both input and output side power supplies. typical values only provided in data sheet.

Regards,

Kalyanraj D

Hello,

This is with reference to the Si824x reference kit.

1. In order to modify the gain, would it be correct to change R29 and R30 (4.99kohms), such that doubling the value will double the gain?

2. For bridge application, what would be a the recommended: use two mono channels with 180deg phase shifted signals or use the unused pin 8 of the comparator to drive another half bridge using a 2nd  Si824x, in which case the feedback of the 2nd half bridge will drive the non-inverting pin of the error amplifier (IC17B/ 18B) as shown in the attachment?

 

Thanks!!

Ranajit.

Can the external mosfet on the Si8710 just be treated like a standard mosfet? For instance, can I use it in the open drain or open source configuration? I see references to it being an open collector (think you mean open drain by the way) only. 

Is it possible for these isolators to be operated with different supply voltages? For example: VDD1=5.0V, VDD2=3.3V.

And, if you have something I must pay attention or drawbacks when i use them in such way, please let me know it.

We are presently using a Si8931 isolated amplifier for high-speed measurements in a high-power motor drive.

One issue we are facing with our system is the possibility of the input amplifier to be supplied with a negative voltage lower than the min -0.5V stated in the data sheet.

The input source voltage can be as low as -4V for 1% of the time and -1.5V for up to 80% of the time.

Can we protect the amplifier with an external series resistor and how can we evaluate its value?

Hello everyone,

I am totally new to this forum looking for a help. Any tips and advice regarding my issue would be appreciated. I am jacksonlevi, working in a Corporate animation Company. I wanted to know that could the VDDA and GNDA actually be configured such that if, for example, a +15V/-5V bi-polar type biasing be fed into the chip and the source/emitter return of the device connected to separate neutral point?Or a different way could be that a 20V supply be placed between those pins, then using a secondary zener diode with resistors and capacitors create a +15V/-5V gate biasing ckt w/ a derived, floating source/emitter return point.Is there anything in the chip itself that would prevent negative biasing or reverse current flow? I have serached for this issue but did not find any right solution. Please help me

Any help would be greatly appreciated!!

Thank you.

Hello,

We have a problem with si3402-B based PoE circuit. Some of devices are producing significantly notable sound when working. Some of them just light buzzing.
It seems there is an oscilation over optocoupler feedback and isolation transformer is making the sound. We are using PC3H7J00000F optocoupler. Schematic is attached.

Could you give us some advice how to eliminate the problem.

Thank you.

 

  

In a safety-critical application the Si5752 controls the gate of a MOSFET. To be sure that the MOSFET is certainly always open, ie that there are no charges in the gate that can activate it spuriously, it is not very clear if the output of the Si8752 guarantees this function in the event that its input is not activated or if it is better to put a resistance of some MOhm between gate and source or a FET. In the data sheet, too, the activation mechanism of the MCap1, -2 inputs is not very clear. Are they just dynamic and their action mutually exclusive with their own device input activation?

I would like to ask if the SI8431BB-D-IS1 and SI8431BB-C-IS1 can look different, because I bought the SI8431BB-D-IS1, but when I give the EN1 pin low, A3 is low. Not high resistance, I guess it may be SI8431BB-C-IS1, so I would like to ask if the two appearances can be seen to distinguish it?

Hi,

We are using the SI3404 chip to use POE, When we used the standard PoE injectors, it works perfectly. 

But when we used the non-standard PoE injectors,  the chip would burn out  occasionally.

Our design is a reference of Si3404-Buck EVB board.  Is the SI3404 not support the non-standard PoE injectors ?

Thank you for your Help.

Is an external gate resistor required to limit the initial peak current to the specified max source and sink currents? The MOSFET I am driving has an internal gate resistance of 0,25 ohm. (2x BSB056N10NN3) With V_DD=12V and R_N=1,0 ohm, the peak sink current will be 12V/1,25ohm=9,6A, which exceed the max specified sink current of 4,0A. Should I add an external gate resistor so that R_total=12V/4A? I.e. an external gate resistor of 1,8ohm. However this increase the switching losses as described in AN490.

(The power dissipation is well below the limits. The question is only about the driver output peak current and is not dependent on the gate charge.)

Dear colleagues!
I am building a galvanically isolated CAN transceiver using the SI8422.
Does anyone have experience using this chip at different supply voltages Vdd1 and Vdd2? (Vdd1 = 3.3V, Vdd2 = 5V)?
Thank you in advance.

Hello we are trying to implement si8271 mosfet driver in our design. Typical driver schematic presented in datasheets is fairly simple but we are having troubles making it work.   WE have rechecked all the supply voltages.  EN pin has 3.3V,  VDDI 3.3V reference to GNDI. ON VI pin we tried signal from generator 3.3V DC voltage.  VDD pin has 9V reference to GND.  VO+ had 2ohm resistor and VO- 10ohms. both resistors connected to mosfet and to GND through 10kohm resistor.  Problem  is that driver output doesn't react in any  way to any changes in input.  it gives about 1.4V  from VO+ pin  and that's it.   What could be the cause of this  since schematic is very simple ?  We tried to resolder new chip but it wasn't the case. New chip behaves same way. Maybe this chip is very sensitive to soldering temperature ? and is very easily damaged (we had no such a issues with si8274).   Or maybe resistor values at VO+ and VO- are critical for correct operation ?.  In theory driver should work and we should see changes on pins even without anything connected to them. What would be correct way to test si8271 if its faulty or not ?

 

Can you post an IBIS model for the output stage of the Si8274 isolator?