MOTOROLA MC14521BFEL, MC14521BF, MC14521BDR2, MC14521BD, MC14521BCP Datasheet

 Semiconductor Components Industries, LLC, 2000

March, 2000 – Rev. 3

1 Publication Order Number:

MC14521B/D

MC14521B

24-Stage Frequency Divider

The MC14521B consists of a chain of 24 flip–flops with an input
circuit that allows three modes of operation. The input will function as
a crystal oscillator, an RC oscillator, or as an input buffer for an
external oscillator. Each flip–flop divides the frequency of the
previous flip–flop by two, consequently this part will count up to 2

24

=
16,777,216. The count advances on the negative going edge of the
clock. The outputs of the last seven–stages are available for added
flexibility.

• All Stages are Resettable

• Reset Disables the RC Oscillator for Low Standby Power Drain

• RC and Crystal Oscillator Outputs Are Capable of Driving External

Loads

• Test Mode to Reduce Test Time

• V

DD

′ and VSS′ Pins Brought Out on Crystal Oscillator Inverter to

Allow the Connection of External Resistors for Low–Power
Operation

• Supply Voltage Range = 3.0 Vdc to 18 Vdc

• Capable of Driving Two Low–power TTL Loads or One Low–power

Schottky TTL Load over the Rated Temperature Range.

MAXIMUM RATINGS (Voltages Referenced to V

SS

) (Note 2.)

Symbol

Parameter Value Unit

V

DD

DC Supply Voltage Range –0.5 to +18.0 V

Vin, V

out

Input or Output Voltage Range

(DC or Transient)

–0.5 to VDD + 0.5 V

Iin, I

out

Input or Output Current

(DC or Transient) per Pin

±10 mA

P

D

Power Dissipation,

per Package (Note 3.)

500 mW

T

A

Ambient Temperature Range –55 to +125 °C

T

stg

Storage Temperature Range –65 to +150 °C

T

L

Lead Temperature

(8–Second Soldering)

260 °C

2. Maximum Ratings are those values beyond which damage to the device

may occur.

3. Temperature Derating:

Plastic “P and D/DW” Packages: – 7.0 mW/_C From 65_C T o 125_C

This device contains protection circuitry to guard against damage due to high
static voltages or electric fields. However, precautions must be taken to avoid
applications of any voltage higher than maximum rated voltages to this
high–impedance circuit. For proper operation, V

in

and V

out

should be constrained

to the range V

SS

v (Vin or V

out

) v VDD.

Unused inputs must always be tied to an appropriate logic voltage level (e.g.,
either V

SS

or VDD). Unused outputs must be left open.

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A = Assembly Location
WL or L = Wafer Lot
YY or Y = Year
WW or W = Work Week

Device Package Shipping

ORDERING INFORMATION

MC14521BCP PDIP–16 2000/Box
MC14521BD SOIC–16 48/Rail
MC14521BDR2 SOIC–16 2500/Tape & Reel

1. For ordering information on the EIAJ version of
the SOIC packages, please contact your local
ON Semiconductor representative.

MARKING

DIAGRAMS

1

16

PDIP–16

P SUFFIX

CASE 648

MC14521BCP

AWLYYWW

SOIC–16

D SUFFIX

CASE 751B

1

16

14521B

AWLYWW

SOEIAJ–16

F SUFFIX

CASE 966

1

16

MC14521B

AWLYWW

MC14521BFEL SOEIAJ–16 See Note 1.
MC14521BFR2 SOEIAJ–16 See Note 1.

MC14521BF SOEIAJ–16 See Note 1.

MC14521B

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2

PIN ASSIGNMENT

13

14

15

16

9

10

11

125

4

3

2

1

8

7

6

Q20

Q21

Q22

V

DD

IN 1

Q18

Q19

OUT 2

V

SS

′

RESET

Q24

V

SS

IN 2

V

DD

′

Q23

BLOCK DIAGRAM

Output Count Capacity

Q18 2

18

= 262,144

Q19 2

19

= 524,288

Q20 2

20

= 1,048,576

Q21 2

21

= 2,097,152

Q22 2

22

= 4,194,304

Q23 2

23

= 8,388,608

Q24 2

24

= 16,777,216

STAGES

18 THRU 24

STAGES

1 THRU 17

Q18 Q19 Q20 Q21 Q22 Q23 Q24

10 11 12 13 14 15 1

2

6

IN 2

9

IN 1

7

RESET

V

DD

= PIN 16

VSS = PIN 8

5

3

4

OUT 1

V

DD

′

V

SS

′

OUT2

MC14521B

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3

ELECTRICAL CHARACTERISTICS (Voltages Referenced to V

SS

)

V

– 55_C 25_C 125_C

Characteristic Symbol

V

DD

Vdc

Min Max Min Typ

(4.)

Max Min Max

Unit

Output Voltage “0” Level

V

in

= VDD or 0

V

OL

5.0
10
15

—
—
—

0.05

0.05

0.05

—
—
—

0
0
0

0.05

0.05

0.05

—
—
—

0.05

0.05

0.05

Vdc

“1” Level

V

in

= 0 or V

DD

V

OH

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

—
—
—

Vdc

Input Voltage “0” Level

(V

O

= 4.5 or 0.5 Vdc)

(V

O

= 9.0 or 1.0 Vdc)

(V

O

= 13.5 or 1.5 Vdc)

V

IL

5.0
10
15

—
—
—

1.5

3.0

4.0

—
—
—

2.25

4.50

6.75

1.5

3.0

4.0

—
—
—

1.5

3.0

4.0

Vdc

“1” Level

(V

O

= 0.5 or 4.5 Vdc)

(V

O

= 1.0 or 9.0 Vdc)

(V

O

= 1.5 or 13.5 Vdc)

V

IH

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

—
—
—

Vdc

Output Drive Current

(V

OH

= 2.5 Vdc) Source

(V

OH

= 4.6 Vdc) Pins 4 & 7

(V

OH

= 9.5 Vdc)

(V

OH

= 13.5 Vdc)

I

OH

5.0

5.0
10
15

– 1.2
– 0.25
– 0.62

– 1.8

—
—
—
—

– 1.0
– 0.2
– 0.5
– 1.5

– 1.7

– 0.36

– 0.9
– 3.5

—
—
—
—

– 0.7
– 0.14
– 0.35

– 1.1

—
—
—
—

mAdc

(VOH = 2.5 Vdc) Source
(V

OH

= 4.6 Vdc) Pins 1, 10,

(V

OH

= 9.5 Vdc) 1 1, 12, 13, 14

(V

OH

= 13.5 Vdc) and 15

5.0

5.0
10
15

– 3.0

– 0.64

– 1.6
– 4.2

—
—
—
—

– 2.4

– 0.51

– 1.3
– 3.4

– 4.2
– 0.88
– 2.25

– 8.8

—
—
—
—

– 1.7

– 0.36

– 0.9
– 2.4

—
—
—
—

mAdc

(VOL = 0.4 Vdc) Sink
(V

OL

= 0.5 Vdc)

(V

OL

= 1.5 Vdc)

I

OL

5.0
10
15

0.64

1.6

4.2

—
—
—

0.51

1.3

3.4

0.88

2.25

8.8

—
—
—

0.36

0.9

2.4

—
—
—

mAdc

Input Current I

in

15 — ± 0.1 — ±0.00001 ± 0.1 — ± 1.0 µAdc

Input Capacitance

(V

in

= 0)

C

in

— — — — 5.0 7.5 — — pF

Quiescent Current

(Per Package)

I

DD

5.0
10
15

—
—
—

5.0
10
20

—
—
—

0.005

0.010

0.015

5.0
10
20

—
—
—

150
300
600

µAdc

Total Supply Current

(5.) (6.)

(Dynamic plus Quiescent,
Per Package)
(C

L

= 50 pF on all outputs, all

buffers switching)

I

T

5.0
10
15

IT = (0.42 µA/kHz) f + I

DD

IT = (0.85 µA/kHz) f + I

DD

IT = (1.40 µA/kHz) f + I

DD

µAdc

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

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

6. To calculate total supply current at loads other than 50 pF:
I

T(CL

) = IT(50 pF) + (CL – 50) Vfk

where: I

T

is in µA (per package), CL in pF, V = (VDD – VSS) in volts, f in kHz is input frequency, and k = 0.003.

MC14521B

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4

SWITCHING CHARACTERISTICS

(7.)

(C

L

= 50 pF, T

A

= 25_C)

Characteristic

Symbol

V

DD

Vdc

Min Typ

(8.)

Max Unit

Output Rise and Fall Time (Counter Outputs)

t

TLH

, t

THL

= (1.5 ns/pF) CL + 25 ns

t

TLH

, t

THL

= (0.75 ns/pF) CL + 12.5 ns

t

TLH

, t

THL

= (0.55 ns/pF) CL + 12.5 ns

t

TLH

, t

THL

5.0
10
15

—
—
—

100

50
40

200
100

80

ns

Propagation Delay Time

Clock to Q18

t

PHL

, t

PLH

= (1.7 ns/pF) CL + 4415 ns

t

PHL

, t

PLH

= (0.66 ns/pF) CL + 1667 ns

t

PHL

, t

PLH

= (0.5 ns/pF) CL + 1275 ns

t

PHL

, t

PLH

5.0
10
15

—
—
—

4.5

1.7

1.3

9.0

3.5

2.7

µs

Clock to Q24

t

PHL

, t

PLH

= (1.7 ns/pF) CL + 5915 ns

t

PHL

, t

PLH

= (0.66 ns/pF) CL + 2167 ns

t

PHL

, t

PLH

= (0.5 ns/pF) CL + 1675 ns

5.0
10
15

—
—
—

6.0

2.2

1.7

12

4.5

3.5

Propagation Delay Time

Reset to Q

n

t

PHL

= (1.7 ns/pF) CL + 1215 ns

t

PHL

= (0.66 ns/pF) CL + 467 ns

t

PHL

= (0.5 ns/pF) CL + 350 ns

t

PHL

5.0
10
15

—
—
—

1300

500
375

2600
1000

750

ns

Clock Pulse Width t

WH(cl)

5.0
10
15

385
150
120

140

55
40

—
—
—

ns

Clock Pulse Frequency f

cl

5.0
10
15

—
—
—

3.5

9.0
12

2.0

5.0

6.5

MHz

Clock Rise and Fall Time t

TLH

, t

THL

5.0
10
15

—
—
—

—
—
—

15

5.0

4.0

µs

Reset Pulse Width t

WH(R)

5.0
10
15

1400

600
450

700
300
225

—
—
—

ns

Reset Removal Time t

rem

5.0
10
15

30

0

– 40

– 200
– 160
– 110

—
—
—

ns

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

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

Figure 1. Power Dissipation Test Circuit and Waveform

PULSE

GENERATOR

V

DD

V

DD

V

DD

V

SS

V

SS

Q18
Q19

Q20
Q21
Q22
Q23
Q24

C

L

C

L

C

L

C

L

C

L

C

L

C

L

I

D

IN 2

R

500 µF

0.01 µF
CERAMIC

20 ns 20 ns

V

DD

0 V

V

in

50% DUTY CYCLE

90%

10%

50%