ELEG 3224 Lecture Notes - Lecture 3: Channel Length Modulation, Current Mirror, Mosfet
31 Jan 2017
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Document Summary
Ic biasing, mosfet and bjt current mirrors, mosfet. Biasing in ic circuit design is based on using constant-current sources. Constant dc current is generated at one location and then copied at other locations. Advantage of spending effort on designing stable reference current then simply copying it as much as needed. Must be kept at a value that establishes saturation. In order to act as a constant current source. Currents from will be equal when (since they would have the same ) Increasing will increase according to incremental output resistance . Both transistors have finite output resistance given by. Remembering once reference currents are established they can be copied. To ensure saturation and form a current mirror. Since it the current can be found from the reference current and the current mirror it forms with. Considering is sufficiently high enough to ignore base currents.
