One, integrated circuit and its characteristic

 

Integrated circuit is to use oxidation, photoetching, diffuse, denotative, the compositive craft such as evaporate aluminium, transistor, resistor, the concentration such as lead is made in a small semiconductor (silicon) base piece on, make an integrated circuit. Can divide by the function for analogue integrated circuit and digital integrated circuit two kinds big, among them amplifier of integrated circuit operation (linear integrated circuit, compositive carry puts the following abbreviation) it is the application in analogue integrated circuit is the widest, it is the circuit of enlarge of direct coupling multistage of a tall gain essentially.

 

The characteristic of integrated circuit

 

1.Discrete component precision is not tall, suffer temperature the impact is big also, but yuan the performance data of parts of an apparatus is more consistent, symmetry is good. Agree with compositive differential circuit.

 

2.Block is worth too tall or too low resistance to be made not easily, in integrated circuit pipe is used more and resistor is used less.

 

3.Large electric capacity and inductance are made not easily, multistage magnifies circuit uses direct coupling.

 

4.In integrated circuit, to do not make technology sophisticated, use the pipe of onefold type as far as possible, component sort also wants little so, integrated circuit is mixed in the difference with formally and very bigger than having look of discrete element circuit characteristic. Commonly used diode and the constant current source that dynatron constitutes and current source replace great collector resistor and offer slant tinily quantity electric current, diode is replaced with the emissive knot of dynatron

 

5.In integrated circuit, NPN is in charge of make it is fore-and-aft canal, β big;PNP is in charge of make it is transverse canal, β is small and PN knot compression is tall. NPN canal and PNP canal cannot conjugate is used. To PNP canal, β and (β+1) difference is big, IB often cannot oversight.

 

2, the action of the composition of road of compositive carry discharge and departmental cent

 

1.Composition

 

 

2.Action

 

If plan institute is shown, compositive carry puts circuit to be comprised by 4 parts, inputting class is the resistor of high-powered differential enlarge that a double end inputs, ask its Ri is tall, aod is big, KCMR is big, static electric current is small, the stand or fall of this class affects the most performance data that compositive carry puts directly, newer change is so most. The action of intermediate class is to make compositive carry is put have stronger enlarge capacity, reason uses multiple tube to do enlarge to be in charge of more, become collector load with current source. Output level asks a wired sex range is wide, output resistance is little, nonlinear lack fidelity small wait for a characteristic. Slant the static work place that buy circuit uses at installing compositive carry to put various enlarge circuit

 

3, the voltage that compositive carry puts transmits character

 

 

1. symbol

 

Inphase input end states input voltage and output voltage are phasic and identical, be like UP >0, criterion UO >0;uP <0, criterion UO <0.

 

Input end to state input voltage and output voltage are phasic and contrary instead, be like UN >0, criterion UO <0; conversely UN <0, criterion UO >0.

 

The transmission of 2. voltage is characteristic

 

 

Alleged voltage transmits character, it is curve of a kind of relation is like graph 4-3 actually, output the relation curve between voltage Uo and input voltage Ui namely. Relation curve is two area apparently, linear enlarge area and saturated area, diagonal reflected the concern between input of linear enlarge area and output. Slope is Av=uo/ui of voltage enlarge multiple, output and input amplitude (or virtual value) than, two end are horizontal the phenomenon that is saturated area, make clear output to voltage Uo does not follow input Ui =uP – UN and change, however constant value + Uom(or – Uom) , still see by characteristic curve linear area is very narrow, because Aod of multiple of enlarge of wrong standard open loop is very tall,this is, can amount to hundred thousands of times, become only Ui = | UP – UN | <When 28μV, circuit just works online sex area.

 

4, compositive carry puts medium current source circuit

 

1. mirror current source (graph 4-5.4)

 

1 composition

 

By dynatron T2 and the composition that receive diode T1, emissive knot is shunt-wound, namely UBE1 = UBE2

 

 

2 jobs principle

 

IC2 = IR /(1+2/β) (4-1)

 

If β>>2, criterion

 

IC2≈IR = (VCC-UBE)/R (4-2)

 

3 problems

 

A)IC2 should make IC2 small along with VCC change; B) , r must very big

 

C) outputs resistor without inhibition D) to temperature drift not quite big RO =rce2

 

2. Wilson current source (graph 4-7.5)

 

1 composition

 

T3 was added on foundation of mirror current source

 

2 jobs principle

 

(4-3)

 

 

Among them

 

IR =(VCC-UBE3-UBE2)/R (4-3)

 

3 characteristics and problem

 

Constant current inputs the Re3 ≈rbe /2 that is in charge of T3, make its IC3 stability rises greatly, the error between IC3 and IR also is reduced greatly. But when power source voltage changes, IC3 and IR change by same proportion almost. When the requirement is UA class, r is too big still.

 

3. small current source (graph 4-9. 6)

 

1 composition

 

Blast off in what T2 provides mirror current source extremely on add receive resistor Re.

 

 

 

 

2 jobs principle

 

UT.ln(IC1 /IC2)=IC2Re (4-4)

 

3 characteristics

 

Small and firm. Use not big Re to be able to make IC2 is UA class. Because introduce Re, IC2 is more stable. As a result of UBE2 <

 

4. multichannel current source

 

With same an IR of parameter electric current, at the same time generation exports electricity a few times, to many enlarge the canal is offerred slant buy electric current or as active load.

 

The application of 5. current source

 

1 put for compositive carry various offer small and firm slant buy electric current

 

The 2 active that regard each enlarge as class are laden, increase voltage gain.

 

Advantage: (A) replaces great resistance with dynatron, save silicon chip area, reduce cost.

 

(B) can score very tall gain with less progression, because progression is little,output block the Chinese People’s Anti-Japanese Military and Political College with circuit,

 

(Because C) puts bassoon collector electric current and collector potential to have nothing to do, circuit can work inside range of very wide power source voltage and slant buy electric current is basic and constant.