CMPE 118 MECHATRONICS Digital I/O Transistors and Mosfets

CMPE 118 MECHATRONICSCMPE 118 MECHATRONICS

Digital I/O

Transistors and Mosfets


Bipolar Transistors used as Switches

NPN PNPBase Base

Emitter

Collector

Collector

Emitter

How do we get them turned on?

Forward bias the Base:Emitter Junction

Supply current

How much current?

1/10th as much as the Collector:Emitter current

How do we know if we have been successful?

Vce will drop to about 0.2V


Bipolar Transistors used as Switches




MOSFET Transistors used as Switches

N-Channel P-ChannelGate Gate

Source

Drain

Source

Drain


|VGS| > Threshold N-Channel: G > S, P-Channel G < S


RDS will drop to a low value


MOSFET Transistors used as Switches




What is CMOS ?

Complementary MOSN-Channel and P-Channel used in Pairs


What is CMOS ?


Digital Inputs

Logic Levels

Voltage Levels

0 1

< Low Threshold > High Threshold


What Are the Voltage Levels?That Depends onthe type of logic...

Transistor Transistor Logic

High-speed CMOS

High-speed CMOS, TTL input

Original CMOS


R ecom m ended O pera ting C ond itions

Sy m b o l Pa ram e te r D M 5 4 L S 0 0 D M 7 4 L S 0 0 U n i tsM in N o m M a x M in N o m M a x

VCC Su p p ly Vo lta g e 4 .5 5 5 .5 4 .7 5 5 5 .2 5 VV IH H ig h L e ve l In pu t Vo lta g e 2 2 V

V IL L o w L e ve l In pu t Vo lta g e 0 .7 0 .8 VIOH H ig h L e ve l O u tp u t Cur re n t -0 .4 0 .4 m A

IO L L o w L e ve l O u tp u t Cur re n t 4 8 m A

TA F r e e A i r O p era t in g T em p era tu re 5 5 1 2 5 0 7 0 °C-

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How is the Voltage Specified?


It takesVoltage and Current

to make a device workE lec trica l C ha rac te ris tics ove r re co m m e n d e d oper a t in g fre e a ir tem pe ra tu r e ra n g e (u n le ss o the r w ise no ted )

Sy m b o l Pa r am e te r Co n d it ion s M inT y p

M a x U n i ts(N o te 1 )

V I In pu t C la m p Vo lta g e VCC M in , II 1 8 m A 1 .5 V

V OH H ig h L e ve lO u tp u t V CC M in , IOH M a x , D M 5 4 2 .5 3 .4 VVo lta g e V IL M a x D M 7 4 2 .7 3 .4

V O L L o w L e ve l O u tp u t VCC M in , IO L M a x , D M 5 4 0 .2 5 0 .4Vo lta g e VIH M in D M 7 4 0 .3 5 0 .5 V

IO L 4 m A , VCC M in D M 7 4 0 .2 5 0 .4

I I In pu t Cur re n t @ M a x V CC M a x , VI 7 V0 .1 m AIn pu t Vo lta g e

I IH H ig h L e ve l In pu t Cur re n t V CC M a x , VI 2 .7 V 2 0 A

I IL L o w L e ve l In pu t Cur re n t V CC M a x , VI 0 .4 V 0 .3 6 m A

I OS Sh o r t C ircu it V CC M a x D M 5 4 2 0 1 0 0 m AO u tp u t Cur re n t (N o te 2 ) D M 7 4 2 0 1 0 0

I CCH Su p p ly Cur re n t w it h VCC M a x0 .8 1 .6 m AO u tp u ts H ig h

I C C L Su p p ly Cur re n t w it h VCC M a x 2 .4 4 .4 m AO u tp u ts L o w

=

==

==

==

=

=

=

=

=

=

=

==

=

=

= -

-- -

-

-

-


Inter-Connecting


Bipolar TTL OutputDigital Logic


Resistor values shown are nominal.

6 k

Input A

Output Y

GND

VCC

3.4 k 1.6 k

100

1 k

Open Collector OutputDigital Logic


CMOS Totem PoleDigital Logic


Sizing a pull-up Resistor: Max & Min.

1 2

74HC05

U1A

???R1

+5V

1 2

74HC04

U2A

3 4

U2B

5 6

U2C



74HC04


74HC04


Absolute Maximum Ratings

Not so Useful

Quite Useful


Absolute Maximum Ratings


VOL

VIL

VIH

VOH

HIGH

LOW

ABNORMAL

High-StateDC Noise Margin

Low-StateDC Noise Margin

For TTL For CMOS

VOL=0.4VVIL=0.8VVIH=2.0VVOH=2.4V

VOL=0.5VVIL=1.5VVIH=3.5VVOH=4.5V

@Vcc=5V

time

Logic Levelsand

Noise Margins


What about Slowly Changing Inputs?


How do you get Hysterisis ?

1) Schmitt Trigger inputs

2) Comparator with Hysterisis

Vin Vout

5V

LM339

R3

RpullupR1

R2



74HC14


The DarlingtonPower Outputs



DS3658


DS3658



ULN2003A(1 of 7 per package)


ULN2003A Specifications


Not all 7 at once !

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CMPE 118 MECHATRONICS Digital I/O Transistors and Mosfets