MOTOROLA CMOS LOGIC DATA

MC14521B

4

Figure 2. Switching Time Test Circuit and Waveforms

PULSE

GENERATOR

Q18

Q19

Q20

Q21

Q22

Q23

Q24

IN 2

R

VDD

VDD′

VSS

VSS′

CL

CL

CL

CL

CL

CL

CL

VDD

20 ns

20 ns

20 ns

10%

50%

90%

10%

50%

90%

IN 2

Qn

tPLH

tPHL

tTLH

tTHL

tWL

tWH

Characteristic

500 kHz

Circuit

50 kHz

Circuit

Unit

Crystal Characteristics

Resonant Frequency

Equivalent Resistance, RS

500

1.0

50

6.2

kHz

k

Ω

External Resistor/Capacitor Values

Ro

CT

CS

47

82

20

750

82

20

k

Ω

pF

pF

Frequency Stability

Frequency Change as a Function

of VDD (TA = 25_C)

VDD Change from 5.0 V to 10 V

VDD Change from 10 V to 15 V

Frequency Change as a Function

of Temperature (VDD = 10 V)

TA Change from – 55_C to + 25_C

MC14521 only

Complete Oscillator*

TA Change from +25_C to + 125_C

MC14521 only

Complete Oscillator*

+ 6.0

+ 2.0

– 4.0

+ 100

– 2.0

– 160

+ 2.0

+ 2.0

– 2.0

+ 120

– 2.0

– 560

ppm

ppm

ppm

ppm

ppm

ppm

*Complete oscillator includes crystal, capacitors, and resistors.

Figure 4. Typical Data for Crystal Oscillator Circuit

Figure 3. Crystal Oscillator Circuit

VDD

VDD

VDD′

VSS

VSS′

OUT 1

OUT 2

Q18

Q19

Q20

Q21

Q22

Q23

Q24

IN 1

IN 2

R

R*

R*

CS

CT

Ro

18 M

* Optional for low power operation,

10 k

Ω ≤ R ≤ 70 kΩ.