Dependent source

百度人民网北京11月7日电（陈羽）11月7日上午，顺义区在北京中国国际展览中心新馆隆重举行“顺义区第二十七届119消防宣传月活动”启动仪式。

In the theory of electrical networks, a dependent source is a voltage source or a current source whose value depends on a voltage or current elsewhere in the network.^[1]

Dependent sources are useful, for example, in modeling the behavior of amplifiers. A bipolar junction transistor can be modeled as a dependent current source whose magnitude depends on the magnitude of the current fed into its controlling base terminal. An operational amplifier can be described as a voltage source dependent on the differential input voltage between its input terminals.^[1] Practical circuit elements have properties such as finite power capacity, voltage, current, or frequency limits that mean an ideal source is only an approximate model. Accurate modeling of practical devices requires using several idealized elements in combination.

Classification

Voltage-controlled voltage source

Voltage-controlled current source

Current-controlled current source

Current-controlled voltage source

Dependent sources can be classified as follows:

Voltage-controlled voltage source: The source delivers the voltage as per the voltage of the dependent element. $V={f_{a}}({v_{x}})$
Voltage-controlled current source: The source delivers the current as per the voltage of the dependent element. $I={f_{b}}({v_{x}})$
Current-controlled current source: The source delivers the current as per the current of the dependent element. $I={f_{c}}({i_{x}})$
Current-controlled voltage source: The source delivers the voltage as per the current of the dependent element. $V={f_{d}}({i_{x}})$

Dependent sources are not necessarily linear. For example, MOSFET switches can be modeled as a voltage-controlled current source when $V_{\rm {DS}}>V_{\rm {GS}}-V_{T}$ and $V_{\rm {GS}}>V_{T}$ .

However, the relationship between the current flowing through it and $V_{\rm {DS}}$ is approximately:

I_{\rm {D}}={\frac {\mu _{n}C_{\rm {ox}}}{2}}{\frac {W}{L}}(V_{\rm {GS}}-V_{\rm {th}})^{2}\left(1+\lambda (V_{\rm {DS}}-V_{\rm {DSsat}})\right).

^[2]^[3]

In this case, the current is not linear to $V_{\rm {DS}}$ , but rather approximately proportional to the square of $V_{\rm {DS}}-V_{T}$ .

As for the case of linear dependent sources, the proportionality constant between dependent and independent variables is dimensionless if they are both currents (or both voltages). A voltage controlled by a current has a proportionality factor expressed in units of resistance (ohms), and this constant is sometimes called "transresistance". A current controlled by a voltage has units of conductance (siemens), and is called "transconductance". Transconductance is a commonly used specification for measuring the performance of field effect transistors and vacuum tubes.^[1]

References

^ ^a ^b ^c I. D. Mayergoyz, Wes Lawson Basic electric circuit theory: a one-semester text Gulf Professional Publishing, 1996 ISBN 0-12-480865-4, Chapter 8 "Dependent sources and operational amplifiers"
^ PR Gray; PJ Hurst; SH Lewis; RG Meyer (27 March 2001). §1.5.2 p. 45. Wiley. ISBN 0-471-32168-0.
^ A. S. Sedra; K.C. Smith (2004). Microelectronic circuits (Fifth ed.). New York: Oxford. p. 552. ISBN 0-19-514251-9.

[ML96-1] I. D. Mayergoyz, Wes Lawson Basic electric circuit theory: a one-semester text Gulf Professional Publishing, 1996 ISBN 0-12-480865-4, Chapter 8 "Dependent sources and operational amplifiers"

[Gray-Meyer2-2] PR Gray; PJ Hurst; SH Lewis; RG Meyer (27 March 2001). §1.5.2 p. 45. Wiley. ISBN 0-471-32168-0.

[Sedra-3] A. S. Sedra; K.C. Smith (2004). Microelectronic circuits (Fifth ed.). New York: Oxford. p. 552. ISBN 0-19-514251-9.

[1]

[2]

[3]

退休是什么意思	魔术贴是什么	胎位头位是什么意思	霉菌性炎症用什么药效果最好	肾上腺瘤吃什么药可以消除
pg是什么意思	心脏缺血吃什么药好	弯刀裤适合什么人穿	麻木是什么意思	霍家为什么娶郭晶晶
客厅挂画有什么讲究	哈戳戳是什么意思	左下腹疼痛是什么原因女性	凤凰单丛茶属于什么茶	梦到牛是什么预兆
西药是用什么材料做的	icd医学上是什么意思	风热感冒吃什么食物	蕨根粉是什么做的	巧克力囊肿有什么症状表现

什么牌子的助听器最好hcv8jop1ns8r.cn	三月四号什么星座hcv9jop0ns5r.cn	胳膊麻是什么原因hcv8jop7ns4r.cn	一语道破什么意思hcv9jop1ns5r.cn	重庆的市花是什么hcv8jop7ns4r.cn
全身出虚汗多是什么原因造成的hcv9jop6ns6r.cn	窦性心律左室高电压什么意思hcv9jop7ns2r.cn	男人吃荔枝有什么好处hcv9jop1ns1r.cn	猜疑是什么意思hcv9jop5ns5r.cn	金牛男和什么星座女最配hcv9jop5ns4r.cn
2月27是什么星座hcv9jop2ns2r.cn	同房什么感觉hcv8jop3ns5r.cn	瓜子脸适合什么发型hcv8jop1ns4r.cn	无花果什么品种最好吃hcv8jop9ns2r.cn	肛肠科属于什么科hcv8jop3ns3r.cn
铜镯子对人有什么好处hcv9jop2ns6r.cn	tu是什么意思adwl56.com	阴虚吃什么好hcv8jop7ns6r.cn	鼠是什么命bfb118.com	手脚出汗多是什么原因adwl56.com

阳气不足吃什么中成药

Classification

See also

References