1 Intro to BJT Current Mirrors - UC Berkeley Extucberkeleyext.com/documents/IC/X489/1_Intro to BJT Current Mirrors.pdfVincent Chang Intro •Current gain •Output resistance Base

Dr. Vincent Chang (張文清)

Lecture Intro to BJT Current Mirror

Vincent Chang

Copyright © by Knowledge Master, Inc.

Vincent Chang

Intro

• Current gain•Output resistance

Base current compensation

• Concept• Current transfer ratio

Multiple outputs

• npn mirror• pnp mirror• Emitter area


Outline


Review: Discrete-Circuit

EC

2CC

1CC

EC

2CC

1CC

Bias with single supply Bias with two supplies


Review: Discrete-Circuit Bias

EC

2CC

1CC

EC

2CC

1CC

Bias with single supply Bias with two supplies


IC Bias


Current Mirror/Current Source





Differential amplifier


Mode of Operation



Review

Common-emitter I-V


Forward-Active

F-active



Finite Current Gain

BEV

F-active


Finite Current Gain

BEV

TBE VVSC eII

F-active


Finite Current Gain

TBE VVSC eII

F-active

BEV


Finite Current Gain

TBE VVSC eII

F-active

BEV


Finite Current Gain

TBE VVSC eII


Finite Current Gain

TBE VVSC eII


Finite Current Gain

TBE VVSC eII

212 O

CCREF IIII


Finite Current Gain

TBE VVSC eII

212 O

CCREF IIII


Finite Current Gain

21

12

REF

O

II

212 O

CCREF IIII


Finite Early Voltage





A

CEVVSCREF V

VeIII TBE 11



A

BEVVSCREF V

VeIII TBE 11

BEV



A

BEVVSCREF V

VeIII TBE 11

A

OVVSCO V

VeIII TBE 12


Finite Output Resistance

A

BEVVSCREF V

VeIII TBE 11

A

OVVSCO V

VeIII TBE 12




Venice Beach, Los Angeles



2

1slopeoO

O

rVI



2oO

Oout r

IV

R

2

1slopeoO

O

rVI

Vincent Chang

Intro




Multiple outputs



Outline


Key Concept


Key Concept



Base Current Compensation

Base current compensationBasic current mirror


Base Current Compensation

RVVVI BEBECC

REF31



Current Transfer Ratio









21

1

REF

O

II



21

1

REF

O

II

2

21

1

REF

O

II



21

1

REF

O

II

2

21

1

REF

O

II



2

21

1

REF

O

II

)1(2

C

CREF

III



2

21

1

REF

O

II

)1(2

C

CREF

III

)(21

1

REF

O

II



)1(2

C

CREF

III

)(21

1

REF

O

II

2

21

1

REF

O

II

Vincent Chang

Intro




Multiple outputs



Outline


Multiple Outputs


Multiple Outputs


Multiple Outputs


Multiple Outputs

PNP Current mirrors

NPN Current mirrors


Multiple Outputs

RVVVVI BEEBEECC

REF21


Multiple Emitter Areas


Review: Is vs. Emitter Area

ESVv

SC AIeIi TBE npn-BJT physical structure


Current Mirror with Multiple Outputs

PNP Current mirrors

NPN Current mirrors

ESVv

SC AIeIi TBE


Output Current

REFII 3

PNP Current mirrors


Output Current

REFII 3

REFII 35

PNP Current mirrors


Output Current

REFII 3

REFII 35

NPN Current mirrors

REFII 24


Output Current

REFII 3

REFII 35

NPN Current mirrors

REFII 24 REFII 46


WARNING

The course contents are protected under thecopyright laws of the United States, Taiwan andother countries. All intellectual property rights ofthe course contents are reserved by KnowledgeMaster, Inc. Any distributing, copying or publicperformance of such course contents, includingPowerPoint slides and audio sound-track, is strictlyprohibited and may subject the offender to severecriminal penalties. (Title 17, United State Code, Section 501 &506)(本课程内容智慧财产权属Knowledge Master, Inc. 所有，并受到美国，台湾等国家著作权法律保护，禁止任何复制与公开播放。)

Copyright © by Knowledge Master, Inc.

Documents

1 Intro to BJT Current Mirrors - UC Berkeley Extucberkeleyext.com/documents/IC/X489/1_Intro to BJT Current Mirrors.pdfVincent Chang Intro •Current gain •Output resistance Base