MC14490F 查看數據表（PDF） - ON Semiconductor

零件编号

产品描述 (功能)

生产厂家

MC14490F

Hex Contact Bounce Eliminator

ON Semiconductor 

MC14490

SWITCHING CHARACTERISTICS (5.) (CL = 50 pF, TA = 25_C)

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Characteristic

VDD

Symbol

Vdc

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Output Rise Time

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ All Outputs

tTLH

5.0

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Output Fall Time

Oscillator Output

5.0

tTHL

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Debounce Outputs

tTHL

5.0

10

15

Propagation Delay Time

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Oscillator Input to Debounce Outputs

tPHL

5.0

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ tPLH

5.0

10

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ 15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Clock Frequency (50% Duly Cycle)

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ (External Clock)

fcl

5.0

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Setup Time (See Figure 1)

tsu

5.0

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Maximum External Clock Input

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Rise and Fall Time

Oscillator Input

tr, tf

5.0

10

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Oscillator Frequency

fosc, typ

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ OSCout

5.0

Î ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Cext ≥ 100 pF*

10

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

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Laboratory experimentation may be required. Formulas

15

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ are typically ± 15% of actual frequencies.

Min

Typ (6.)

Max

Unit

—

180

360

ns

—

90

180

—

65

130

—

100

200

ns

—

50

100

—

40

80

—

60

120

—

30

60

—

20

40

—

285

570

ns

—

120

240

—

95

190

—

370

740

—

160

320

—

120

240

—

2.8

1.4

MHz

—

6

3.0

—

9

4.5

100

50

80

40

60

30

—

ns

—

—

ns

No Limit

1.5

Hz

Cext (in mF)

4.5

Cext (in mF)

6.5

Cext (in mF)

5. The formulas given are for the typical characteristics only at 25_C.

6. 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 Cext 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)  Cext / (10 mA). For example, If VDD – VSS = 15

V and Cext = 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. To avoid this

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

OSCin

50%

VDD

0V

tPLH

Aout

50% 90%

10%

tr

D1

Cext

D2

VDD

VDD

tPHL

7

9

Aout

90% 50%

10%

OSCin OSCout

tf

OSCin

VDD

50%

0V

tsu

Ain

50%

VDD

0V

MC14490

Figure 1. Switching Waveforms

Figure 2. Discharge Protection During Power Down

http://onsemi.com

4

Share Link: