Motorola MC14490P, MC14490DW, MC14490L Datasheet

MOTOROLA CMOS LOGIC DATA

297

MC14490

   

The MC14490 is constructed with complementary MOS enhancement mode devices, and is used for the elimination of extraneous level changes that result when interfacing with mechanical contacts. The digital contact bounce eliminator circuit takes an input signal from a bouncing contact and generates a clean digital signal four clock periods after the i nput has stabilized. The bounce eliminator circuit will remove bounce on both the “make” and the “break” of a contact closure. The clock for operation of the MC14490 is derived from an internal R–C oscillator which requires only an external capacitor to adjust for the desired operating frequency (bounce delay). The clock may also be driven from an external clock source or the oscillator of another MC14490 (see Figure 5).

NOTE: Immediately after power–up, the outputs of the MC14490 are in indeterminate states.

• Diode Protection on All Inputs

• Six Debouncers Per Package

• Internal Pullups on All Data Inputs

• Can Be Used as a Digital Integrator, System Synchronizer, or Delay

Line

• Internal Oscillator (R–C), or External Clock Source

• TTL Compatible Data Inputs/Outputs

• Single Line Input, Debounces Both “Make” and “Break” Contacts

• Does Not Require “Form C” (Single Pole Double Throw) Input Signal

• Cascadable for Longer Time Delays

• Schmitt Trigger on Clock Input (Pin 7)

• Supply Voltage Range = 3.0 V to 18 V

• Chip Complexity: 546 FETs or 136.5 Equivalent Gates

BLOCK DIAGRAM

Ain1

OSCin7

OSC

out

Bin14

Cin3

Din12

Ein5

Fin10

OSCILLATOR

AND

TWO–PHASE

CLOCK GENERATOR

DATA

SHIFT LOAD

4–BIT STATIC SHIFT REGISTER

1/2–BIT

DELAY

φ1φ

15 A

out

VDD = PIN 16

VSS = PIN 8

φ1φ

2 B

out

13 C

out

4 D

out

11 E

out

6 F

out

IDENTICAL TO ABOVE STAGE



SEMICONDUCTOR TECHNICAL DATA

 Motorola, Inc. 1995

REV 3 1/94



L SUFFIX

CERAMIC

CASE 620

P SUFFIX

PLASTIC

CASE 648

DW SUFFIX

SOIC

CASE 751G

ORDERING INFORMATION

MC14490P Plastic MC14490L Ceramic MC14490DW SOIC

TA = – 55° to 125°C for all packages.

MOTOROLA CMOS LOGIC DATAMC14490

298

MAXIMUM RATINGS* (Voltages Referenced to V

)

Symbol

Parameter

Value

Unit

DC Supply Voltage

– 0.5 to + 18.0

Vin, V

out

Input or Output Voltage (DC or Transient)

– 0.5 to VDD + 0.5

Input Current (DC or Transient), per Pin

± 10

Power Dissipation, per Package†

500

stg

Storage Temperature

– 65 to + 150

Lead Temperature (8–Second Soldering)

260

*Maximum Ratings are those values beyond which damage to the device may occur. †Temperature Derating:

Plastic “P and D/DW” Packages: – 7.0 MW/_C From 65_C To 125_C Ceramic “L” Packages: – 12 mW/_C From 100_C to 125_C

ELECTRICAL CHARACTERISTICS (Voltages Referenced to V

)

– 55_C

25_C

125_C

Characteristic

Symbol

Vdc

Min

Max

Min

Typ #

Max

Min

ÎÎÎ

Max

Unit

Output Voltage

“0” Level

Vin = VDD or 0

5.0 10 15

— — —

0.05

— — —

0 0 0

0.05

— — —

ÎÎÎ

0.05

Vdc

“1” Level

Vin = 0 or V

5.0 10 15

4.95

9.95

14.95

— — —

4.95

9.95

14.95

5.0 10 15

— — —

4.95

9.95

14.95

ÎÎÎ

— — —

Vdc

Input Voltage

“0” Level (VO = 4.5 or 0.5 Vdc) (VO = 9.0 or 1.0 Vdc) (VO = 13.5 or 1.5 Vdc)

5.0 10 15

— — —

1.5

3.0

4.0

— — —

2.25

4.50

6.75

1.5

3.0

4.0

— — —

ÎÎÎ

1.5

3.0

4.0

Vdc

(VO = 0.5 or 4.5 Vdc)

“1 Level” (VO = 1.0 or 9.0 Vdc) (VO = 1.5 or 13.5 Vdc)

5.0 10 15

3.5

7.0 11

— — —

3.5

7.0 11

2.75

5.50

8.25

— — —

3.5

7.0 11

ÎÎÎ

— — —

Vdc

Output Drive Current

Oscillator Output Source

(VOH = 2.5 V) (VOH = 4.6 V) (VOH = 9.5 V) (VOH = 13.5 V)

5.0

5.0 10 15

– 0.6 – 0.12 – 0.23

– 1.4

— — — —

– 0.5 – 0.1 – 0.2 – 1.2

– 1.5 – 0.3 – 0.8 – 3.0

— — — —

– 0.4 – 0.08 – 0.16

– 1.0

ÎÎÎ

— — — —

mAdc

Debounce Outputs

(VOH = 2.5 V) (VOH = 4.6 V) (VOH = 9.5 V) (VOH = 13.5 V)

5.0

5.0 10 15

– 0.9

– 0.19

– 0.6

1.8

— — — —

– 0.75 – 0.16

– 0.5 – 1.5

– 2.2

– 0.46

– 1.2 – 4.5

— — — —

– 0.6

– 0.12

– 0.4 – 1.2

ÎÎÎ

— — — —

Oscillator Output Sink

(VOL = 0.4 V) (VOL = 0.5 V) (VOL = 1.5 V)

5.0 10 15

0.36

0.9

4.2

— — —

0.3

0.75

3.5

0.9

2.3 10

— — —

0.24

0.6

2.8

ÎÎÎ

— — —

mAdc

Debounce Outputs

(VOL = 0.4 V) (VOL = 0.5 V) (VOL = 1.5 V)

5.0 10 15

2.6

4.0 12

— — —

2.2

3.3 10

4.0

9.0 35

— — —

1.8

2.7

8.1

ÎÎÎ

— — —

Input Current

Debounce Inputs (Vin = VDD)

—

2.0

—

0.2

2.0

—

ÎÎÎ

µAdc

Input Current Oscillator — Pin 7

(Vin = VSS or VDD)

—

± 620

—

± 255

± 400

—

ÎÎÎ

± 250

µAdc

Pullup Resistor Source Current

Debounce Inputs (Vin = VSS)

5.0 10 15

175 340 505

375 740

1100

140 280 415

190 380 570

255 500 750

70 145 215

ÎÎÎ

225 440 660

µAdc

Input Capacitance

—

5.0

7.5

—

ÎÎÎ

—

Quiescent Current

(Vin = VSS or VDD, I

out

= 0 µA)

5.0 10 15

— — —

150 280 840

— — —

40 90

225

100 225 650

— — —

ÎÎÎ

90 180 550

µAdc

#Data labelled “Typ” is not to be used for design purposes but is intended as an indication of the IC’s potential performance.

PIN ASSIGNMENT

125

out

OSC

out

OSC

out

MOTOROLA CMOS LOGIC DATA

299

MC14490

SWITCHING CHARACTERISTICS (C

= 50 pF, TA = 25_C)

Characteristic

ÎÎÎÎ

Symbol

Vdc

ÎÎÎÎ

Min

Typ #

Max

Unit

Output Rise Time

All Outputs

ÎÎÎÎ

TLH

5.0 10 15

ÎÎÎÎ

— — —

180

90 65

360 180 130

Output Fall Time Oscillator Output

ÎÎÎÎ

THL

5.0 10 15

ÎÎÎÎ

— — —

100

50 40

200 100

Debounce Outputs

ÎÎÎÎ

THL

5.0 10 15

ÎÎÎÎ

— — —

60 30 20

120

60 40

Propagation Delay Time

Oscillator Input to Debounce Outputs

ÎÎÎÎ

PHL

5.0 10 15

ÎÎÎÎ

— — —

285 120

570 240 190

ÎÎÎÎ

PLH

5.0 10 15

ÎÎÎÎ

— — —

370 160 120

740 320 240

Clock Frequency (50% Duly Cycle)

(External Clock)

ÎÎÎÎ

5.0 10 15

ÎÎÎÎ

— — —

2.8 6 9

1.4

3.0

4.5

MHz

Setup Time (See Figure 1)

ÎÎÎÎ

5.0 10 15

ÎÎÎÎ

100

80 60

50 40 30

— — —

Maximum External Clock Input

Rise and Fall Time Oscillator Input

ÎÎÎÎ

tr, t

5.0 10 15

ОООООООООО

No Limit

Oscillator Frequency

OSC

out

ext

≥ 100 pF*

Note: These equations are intended to be a design guide.

Laboratory experimentation may be required. Formulas are typically ± 15% of actual frequencies.

ÎÎÎÎ

osc

, typ

5.0

ОООООООООО

*The formulas given are for the typical characteristics only at 25_C. #Data labelled “Typ” is not to be used for design purposes but is intended as an indication of the IC’s potential performance.

*POWER–DOWN CONSIDERATIONS

Large values of C

ext

may cause problems when powering down the MC14490 because of the amount of energy stored in the capacitor. When a system containing this device is powered down, the capacitor may discharge through the input protection diodes at Pin 7 or the parasitic diodes at Pin 9. Current through these internal diodes must be limited to 10 mA, therefore the turn–off time of the power supply must not be faster than t = (VDD – VSS)  C

ext

/(10 mA). For example, If VDD – VSS = 15 V and

ext

= 1 µF, the power supply must turn off no faster than t = (15 V)  (1 µF)/10 mA = 1.5 ms. This is usually not a problem

because power supplies are heavily filtered and cannot discharge at this rate.

When a more rapid decrease of the power supply to zero volts occurs, the MC14490 may sustain damage. T o avoid this possi-

bility, use external clamping diodes, D1 and D2, connected as shown in Figure 2.

Figure 1. Switching Waveforms Figure 2. Discharge Protection During Power Down

OSC

out

OSC

0 V

0 V V

0 V

50%

90%

50%

10%

PHL

90%

10%

50%

D1 D2C

ext

OSC

out

MC14490

PLH

1.5

ext

(in µF)

4.5

ext

(in µF)

6.5

ext

(in µF)

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