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rbelli1
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I am designing a circuit to control an LED. The current will be under 40mA and the 2n7000 FET has a maximum operating current of 200mA continuous. See attached schematic. The switch in my final circuit is actually another IC.
I looked up the http://www.fairchildsemi.com/ds/2N%2F2N7000.pdf" and everything looked fine until I got to the Maximum Safe Operating Area on page 6.
20 Volts and 40mA are above the safe operating area with 10 Volts on the gate. Vds will be 20V in the off state but very small after the FET turns on. The solid DC line looks like the maximum continuous power dissipation of the device. The dashed line indicates the power dissipation of Rdson with the specified voltages applied.
Will the attached schematic violate the safe area? If so, why? If not what does the the graph mean?
Many thanks to anyone that can clear up my understanding of this FET
BoB
I looked up the http://www.fairchildsemi.com/ds/2N%2F2N7000.pdf" and everything looked fine until I got to the Maximum Safe Operating Area on page 6.
20 Volts and 40mA are above the safe operating area with 10 Volts on the gate. Vds will be 20V in the off state but very small after the FET turns on. The solid DC line looks like the maximum continuous power dissipation of the device. The dashed line indicates the power dissipation of Rdson with the specified voltages applied.
Will the attached schematic violate the safe area? If so, why? If not what does the the graph mean?
Many thanks to anyone that can clear up my understanding of this FET
BoB
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