Current Sources and Voltage References

214

Characteristics of enhancement-mode MOSFETs

of approximately –0.2%/˚C (approximately 5 mV/˚C, or about 10% for each 45˚C rise

in junction temperature). The curves in Figure 8.9 also show the zero TC point, which

in this example occurs at a V

GS

of about 4.3 volts and at a drain current of about 2.3

Amps. The graph clearly shows that at that point, any change in temperature will have

virtually no effect on the drain current. Beyond that point, however, any change in tem-

perature will change the drain current a little, with either a small positive or a small

negative tempco.

Another important characteristic of the MOSFET is its transconductance/forw ...