第九章数模与模数转换电路 9.1D/A转换器 一D/A转换器的基本原理 对于有权码,先将每位代码按其权的大小转换成相应的模拟量,然后将这些模拟量相加,即可得到与数字量成正比的总模拟量,从而实现了数字/模拟转换

1. Nonlinear resistor A nonlinear resistor is an element whose voltage and current are related by a nonlinear equation

1.A functionf(t) is said to be even iff(t)=(-t). They are symmetrical with respect to the vertical axis. (bn=0)

Let us first define a linear element as passive element that has a linear voltage-current relationship

An ideal transformer is a useful approximation of a very tightly coupled transformer in which the coefficient of coupling is almost unity and both the primary and secondary inductive reactance are extremely large in comparison with the terminating impedance

A current i at Li produces an open circuit voltage u,at L2s dyal

We select one node as a reference node and then define a voltage between each remaining node and the reference node

sinusoidal current or voltage at a given frequency is characterized by only two parameters an amplitude and a phase angle. The complex representation of the voltage or current is also characterized by these same two parameters

The over-damped response---- i()= A,+A, The critically-damped response-- i(t) =e (At+A2) The under-damped- response---it)e-(b1 cos+2 sino)

第四章集成运算放大电路自测题 一、选择合适答案填入空内。 (1)集成运放电路采用直接耦合方式是因为 A.可获得很大的放大倍数B.可使温漂小 C.集成工艺难于制造大容量电容 (2)通用型集成运放适用于放大 A.高频信号 B.低频信号 C.任何频率信号 (3)集成运放制造工艺使得同类半导体管的