UC3610: small forward current support turn on ?

Hi Dimitri,

I have no idea what you mean. :-) Can you draw a schematic?

Kai

hi Kai,

sorry about my bad explanation, because I add a 5k resistor that cause forward current can't meet " the desired current" 

figure 2

FORWARD CURRENT v.s VOLTAGE, the minimum current is 0.001A (1mA) --> is this mean the desired minimum current?

and I want to make sure

when signal level is 1V level , the pull up current is around  0.4mA. ?

is that mean diode is turn on ?

is this situation , what is the forward voltage @25 degree,  0.3V ?

Hi Dimitri,

there is no minimum current requirement for the UC3610. The curve in figure 2 of datasheet only starts at 1mA. But, of course, the UC2610 also works for smaller currents. It's just like with any other usual diode.

Yes, the voltage drop across the diode in your schematic should be about 0.3V, according to (5V - 1V - 0.3V) / 5k = 0.74mA. You can carefully extrapolate the curve in figure 2 for currents smaller than 1mA.

Kai