Datasheet NE556D, MC3456P Datasheet (Motorola)

Device

Operating

Temperature Range

Package



SEMICONDUCTOR

TECHNICAL DATA

DUAL TIMING CIRCUIT

ORDERING INFORMATION

MC3456P
NE556D

0° to +70°C

Plastic DIP

SO–14

PIN CONNECTIONS

Order this document by MC3456/D

P SUFFIX

PLASTIC PACKAGE

CASE 646

D SUFFIX

PLASTIC PACKAGE

CASE 751

(SO–14)

(Top View)

Discharge A
Threshold A

Control A

Reset A

Output A

Trigger A

Gnd

V

CC

Discharge B
Threshold B
Control B

Reset B
Output B
Trigger B

1
2
3
4
5
6
78

9

10

11

12

13

14

1

MOTOROLA ANALOG IC DEVICE DATA

  

The MC3456 dual timing circuit is a highly stable controller capable of
producing accurate time delays, or oscillation. Additional terminals are
provided for triggering or resetting if desired. In the time delay mode of
operation, the time is precisely controlled by one external resistor and
capacitor per timer. For astable operation as an oscillator, the free running
frequency and the duty cycle are both accurately controlled with two external
resistors and one capacitor per timer. The circuit may be triggered and reset
on falling waveforms, and the output structure can source or sink up to
200 mA or drive MTTL circuits.

• Direct Replacement for NE556/SE556 Timers

• Timing from Microseconds through Hours

• Operates in Both Astable and Monostable Modes

• Adjustable Duty Cycle

• High Current Output can Source or Sink 200 mA

• Output can Drive MTTL

• Temperature Stability of 0.005% per °C

• Normally “On” or Normally “Off” Output

• Dual Version of the Popular MC1455 Timer

Figure 1. 22 Second Solid State Time Delay Relay Circuit

Figure 2. Block Diagram (1/2 Shown)

Figure 3. General Test Circuit

T est circuit for measuring DC parameters (to set output and measure parameters):
a) When VS w 2/3 VCC, VO is low.
b) When VS v1/3 VCC, VO is high.
c) When VO is low, Pin 7 sinks current. To test for Reset, set VO high,

c) apply Reset voltage, and test for current flowing into Pin 7. When Reset
c) is not in use, it should be tied to VCC.

1.0 k
Load

MT2

10 k

0.1

µ

F

0.01

µ

F

1

5

2

4

38

6
7

1.0

µ

FC

20 M

G

MT1

–10 V

1N4003

117 Vac/60 Hz

1N4740

3.5 k
250 V

–
+

t = 1.1; R and C = 22 sec
Time delay (t) is variable by
changing R and C (see Figure 16).

10 µF

V

CC

Threshold

Control Voltage

Trigger

2 (12)
3 (11)

6 (8)

5 k

14

5 k

5 k

+

–

Comp

A

+

–

Comp

B

7

Gnd Reset

4 (10)

R

S

Flip

Flop

Q

Inhibit/

Reset

1 (13)

5 (9)

Discharge

Output

R

1/2

MC3456

V

R
Reset 4 8

I

CC

V

CC

700

Discharge

6

Threshold

7

I

th

2.0 k

V

S

Trigger

2

Gnd

1

3

I

Sink

I

Source

V

O

0.01

µ

F

+

5

Control
Voltage

Output

V

CC

1/2

MC3456

 Motorola, Inc. 1996 Rev 2

MC3456

2

MOTOROLA ANALOG IC DEVICE DATA

MAXIMUM RATINGS (T

A

= +25°C, unless otherwise noted.)

Rating Symbol Value Unit

Power Supply Voltage V

CC

+18 Vdc

Discharge Current I

dis

200 mA

Power Dissipation (Package Limitation)

P Suffix, Plastic Package, Case 646

Derate above TA = +25°C

D Suffix, Plastic Package, Case 751

Derate above TA = +25°C

P

D

625

5.0

1.0

8.0

mW

mW/°C

W

mW/°C

Operating Ambient T emperature Range T

A

0 to +70

°C

Storage Temperature Range T

stg

–65 to +150 °C

ELECTRICAL CHARACTERISTICS (T

A

= +25°C, VCC = +15 V, unless otherwise noted.)

Characteristics Symbol Min Typ Max Unit

Supply Voltage V

CC

4.5 – 16 V

Supply Current

VCC = 5.0 V, RL = ∞
VCC = 15 V, RL = ∞ Low State, (Note 1)

I

CC

–
–

6.0
20

12
30

mA

Timing Error (Note 2)

Monostable Mode (RA = 2.0 kΩ; C = 0.1 µF)

Initial Accuracy
Drift with T emperature
Drift with Supply Voltage

Astable Mode (RA = RB = 2.0 kΩ to 100 kΩ; C = 0.01 µF)

Initial Accuracy
Drift with T emperature
Drift with Supply Voltage

–
–
–

–
–
–

0.75
50

0.1

2.25

150

0.3

–
–
–

–
–
–

%

PPM/°C

%/V

%

PPM/°C

%/V

Threshold Voltage V

th

– 2/3 – xV

CC

Trigger V oltage

VCC = 15 V
VCC = 5.0 V

V

T

–
–

5.0

1.67

–
–

V

Trigger Current I

T

– 0.5 – µA

Reset Voltage V

R

0.4 0.7 1.0 V

Reset Current I

R

– 0.1 – mA

Threshold Current (Note 3) I

th

– 0.03 0.1 µA

Control Voltage Level

VCC = 15 V
VCC = 5.0 V

V

CL

9.0

2.6

10

3.33

11

4.0

V

Output Voltage Low

(VCC = 15 V)

I

Sink

= 10 mA

I

Sink

= 50 mA

I

Sink

= 100 mA

I

Sink

= 200 mA

(VCC = 5.0 V)

I

Sink

= 5.0 mA

V

OL

–
–
–
–

–

0.1

0.4

2.0

2.5

0.25

0.25

0.75

2.75
–

0.35

V

Output Voltage High

(I

Source

= 200 mA)

VCC = 15 V

(I

Source

= 100 mA)
VCC = 15 V
VCC = 5.0 V

V

OH

–

12.75

2.75

12.5

13.3

3.3

–

–
–

V

T oggle Rate RA = 3.3 kΩ, RB = 6.8 kΩ, C = 0.003 µF (Figure 17, 19) – – 100 – kHz
Discharge Leakage Current I

dis

– 20 100 nA

Rise Time of Output t

OLH

– 100 – ns

Fall Time of Output t

OHL

– 100 – ns

Matching Characteristics Between Sections

Monostable Mode

Initial Timing Accuracy
Timing Drift with Temperature
Drift with Supply Voltage

–
–
–

1.0

±10

0.2

2.0
–

0.5

%

ppm/°C

%/V

NOTES: 1. Supply current is typically 1.0 mA less for each output which is high.

2.Tested at VCC = 5.0 V and VCC = 15 V.

3.This will determine the maximum value of RA + RB for 15 V operation. The maximum total R = 20 mΩ.

MC3456

3

MOTOROLA ANALOG IC DEVICE DATA

25°C

I

Sink

(mA)

I

Sink

(mA)

VCC, SUPPLY VOLTAGE (Vdc)

I

Sink

(mA)

I

Source

(mA)

Figure 4. Trigger Pulse Width

V

T (min)

, MINIMUM TRIGGER VOLTAGE (X VCC = Vdc)

Figure 5. Supply Current

Figure 6. High Output Voltage

Figure 7. Low Output Voltage

(@ VCC = 5.0 Vdc)

Figure 8. Low Output Voltage

(@ VCC = 10 Vdc)

Figure 9. Low Output Voltage

(@ VCC = 15 Vdc)

0.4

150

125

100

75

50

25

0

PW, PULSE WIDTH (ns MIN)

I

CC

, SUPPLY CURRENT (mA)

1.0

1.0

V

CC

–V

OH

(Vdc)

V

OL

, (Vdc)

0.30.20.10

70°C

25°C

10

8.0

6.0

4.0

2.0

0

155.0 10

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2
0

2.0 5.0 10 20 50 100

25°C

5.0 V ≤ VCC ≤ 15 V

10

1.0

0.1

0.01

1.0 2.0 5.0 10 20 50 100

2.0 5.0 10 20 50 100

10

1.0

0.1

0.01

1.0

2.0 5.0 10 20 50 100

10

1.0

0.1

0.01

25°C

0°C

25°C

V

OL

, (Vdc)

V

OL

, (Vdc)

25°C

MC3456

4

MOTOROLA ANALOG IC DEVICE DATA

TA, AMBIENT TEMPERATURE (°C)

Figure 10. Delay Time versus Supply Voltage

VCC, SUPPLY VOLTAGE (Vdc)

Figure 11. Delay Time versus Temperature

Figure 12. Propagation Delay

versus Trigger Voltage

5.0

0

V

T

(

min

)

, MINIMUM TRIGGER VOLTAGE (x VCC = Vdc)

t

d

, DELAY TIME NORMALIZED

t

d

, DELAY TIME NORMALIZED

, PROPAGATION DELAY TIME (ns)t

pd

1.015

1.010

1.005

1.000

0.995

0.990

0.985
0101510 20

1.015

1.010

1.005

1.000

0.995

0.990

0.985
–75 –50 –25 0 25 50 75 100 125

300

250

200

150

100

50

0

0.1 0.2 0.3 0.4

0°C

70°C

25°C

MC3456

5

MOTOROLA ANALOG IC DEVICE DATA

Figure 13. 1/2 Representative Circuit Schematic

100

Threshold

Comparator

Trigger

Comparator

Flip–Flop Output

V

CC

Threshold

Trigger

Reset

Discharge

Gnd

Discharge

Reset

100 k 5.0 k

5.0 k

e

c b

7.0 k

6.8 k

3.9 k

cb

220

4.7 k

Output

Control Voltage

1.0 k4.7 k 830 4.7 k

10 k

4.7 k

5.0 k

GENERAL OPERATION

The MC3456 is a dual timing circuit which uses as its
timing elements an external resistor/capacitor network. It can
be used in both the monostable (one shot) and astable
modes with frequency and duty cycle, controlled by the
capacitor and resistor values. While the timing is dependent
upon the external passive components, the monolithic circuit
provides the starting circuit, voltage comparison and other
functions needed for a complete timing circuit. Internal to the
integrated circuit are two comparators, one for the input
signal and the other for capacitor voltage; also a flip–flop and
digital output are included. The comparator reference
voltages are always a fixed ratio of the supply voltage thus
providing output timing independent of supply voltage.

Monostable Mode

In the monostable mode, a capacitor and a single resistor
are used for the timing network. Both the threshold terminal
and the discharge transistor terminal are connected together
in this mode (refer to circuit Figure 15). When the input
voltage to the trigger comparator falls below 1/3 VCC the
comparator output triggers the flip–flop so that it’s output sets
low. This turns the capacitor discharge transistor “off” and
drives the digital output to the high state. This condition
allows the capacitor to charge at an exponential rate which is
set by the RC time constant. When the capacitor voltage
reaches 2/3 VCC the threshold comparator resets the
flip–flop. This action discharges the timing capacitor and
returns the digital output to the low state. Once the flip–flop
has been triggered by an input signal, it cannot be retriggered
until the present timing period has been completed. The time

that the output is high is given by the equation t = 1.1 RA C.
Various combinations of R and C and their associated times
are shown in Figure 14. The trigger pulse width must be less
than the timing period.

A reset pin is provided to discharge the capacitor thus
interrupting the timing cycle. As long as the reset pin is low,
the capacitor discharge transistor is turned “on” and prevents
the capacitor from charging. While the reset voltage is
applied the digital output will remain the same. The reset pin
should be tied to the supply voltage when not in use.

Figure 14. Time Delay

C, CAPACITANCE ( F)

µ

100

10

1.0

0.1

0.01

0.001
10

µ

s 100 µs 1.0 ms 10 ms 100 ms 1.0 10 100

td, TIME DELAY (s)

MC3456

6

MOTOROLA ANALOG IC DEVICE DATA

Figure 15. Monostable Circuit Figure 16. Monostable Waveforms

Figure 17. Astable Circuit

(RA = 10 kΩ, C = 0.01 µF, RL = 1.0 kΩ, VCC = 15 V)

t = 20

µ

s/cm

(RA = 5.1 k

Ω

, C = 0.0 1 µF, RL = 1.0 kΩ, RB = 3.9 kΩ, VCC = 15 V)

t = 50

µ

s/cm

Figure 18. Astable Waveforms

Control
Voltage

3 (11)

R

L

+VCC (5.0 to 15 V)

Reset V

CC

14

Discharge

1 (13)

2 (12)

Threshold

0.01

µ

F

7

6 (8)

Trigger

Output

5 (9)

4 (10)

R

A

R

L

C

Gnd

1/2

MC3456

R

B

R

L

+VCC (5.0 V to 15 V)

Reset V

CC

14

Discharge
1 (13)

2 (12)
Threshold

Control

Voltage

0.01

µ

F

7

6 (8)

Trigger

Output

5 (9)

4 (10)

R

A

R

L

C

3 (11)

Gnd

1/2

MC3456

Pin numbers in parenthesis ( ) indicate B–Channel

Astable Mode

In the astable mode the timer is connected so that it will
retrigger itself and cause the capacitor voltage to oscillate
between 1/3 VCC and 2/3 VCC (see Figure 17).

The external capacitor charges to 2/3 VCC through RA and
RB and discharges to 1/3 VCC through RB. By varying the
ratio of these resistors the duty cycle can be varied. The
charge and discharge times are independent of the supply
voltage.

The charge time (output high) is given by:

t1 = 0.695 (RA+RB) C

The discharge time (output low) by:

t2 = 0.695 (RB) C

Thus the total period is given by:

T = t1 + t2 = 0.695 (RA + 2RB) C

The frequency of oscillation is then: f =

1
T

=

(RA +2RB) C

1.44

and may be easily found as shown in Figure 19.

RA +2R

B

R

B

The duty cycle is given by: DC =

To obtain the maximum duty cycle, RA must be as small as
possible; but it must also be large enough to limit the

discharge current (Pin 7 current) within the maximum rating
of the discharge transistor (200 mA).

The minimum value of RA is given by:

R

A

≥

VCC (Vdc)

I7 (A)

≥

VCC (Vdc)

0.2

Figure 19. Free Running Frequency

C, CAPACITANCE ( F)

µ

100

10

1.0

0.1

0.01

0.001

(RA + 2 RB)

0.1 1.0 10 100 1.0 k 10 k 100 k
f, FREE RUNNING FREQUENCY (Hz)

MC3456

7

MOTOROLA ANALOG IC DEVICE DATA

APPLICATIONS INFORMATION

Tone Burst Generator

For a tone burst generator, the first timer is used as a
monostable and determines the tone duration when triggered
by a positive pulse at Pin 6. The second timer is enabled by
the high output of the monostable. It is connected as an
astable and determines the frequency of the tone.

Dual Astable Multivibrator

This dual astable multivibrator provides versatility not
available with single timer circuits. The duty cycle can be
adjusted from 5% to 95%. The two outputs provide two phase
clock signals often required in digital systems. It can also be
inhibited by use of either reset terminal.

(RA + 2RB) C

Figure 20. Tone Burst Generator

Figure 21. Dual Astable Multivibrator

R

T

Trigger

Trigger

Trigger

Reset

4

Discharge

Threshold

7 Gnd

1/2

MC3456

14 V

CC

5

Output

10

Reset

3

9

Control

0.01

µ

F

Output

7 Gnd

0.01 mF

C2

14

V

CC

13 Discharge

12 Threshold

8

11

Control

R

B

R

A

+ 15 V

Gnd

C1–

R1

C1

Reset

2

Discharge

1

4

14

10 k

5

1N914 1N914

10 k

9

Output

Trigger

10 Reset

+15 V

R2

Threshold

12

13

Discharge

C2

Gnd

11

Control
Voltage

0.001

8

Output

0.001

Output

6

37

Gnd

f =

0.91

(R1 + R2) C

for C1 = C2 Duty Cycle

R2

R1 + R2

t = 1.1 RT C1

f =

1.44

Control
Voltage

Threshold

Trigger

1/2

MC3456

1/2

MC3456

1/2

MC3456

6

1

2

MC3456

8

MOTOROLA ANALOG IC DEVICE DATA

Pulse Width Modulation

If the timer is triggered with a continuous pulse train in the
monostable mode of operation, the charge time of the
capacitor can be varied by changing the control voltage at
Pin 3. In this manner, the output pulse width can be
modulated by applying a modulating signal that controls the
threshold voltage.

Test Sequences

Several timers can be connected to drive each other for
sequential timing. An example is shown in Figure 24 where
the sequence is started by triggering the first timer which runs
for 10 ms. The output then switches low momentarily and
starts the second timer which runs for 50 ms and so forth.

Figure 22. Pulse Width Modulation Waveforms

Figure 23. Pulse Width Modulation Circuit

t = 0.5 ms/cm

(RA = 10 kW, C = 0.02 mF, VCC = 15 V)

+VCC (5.0 V to 15 V)

R

L

4 (10)
Reset

V

CC

14

R

A

Discharge
1 (13)

Threshold
2 (12)

Control
3 (11)

C

Modulation

Input

Output

5 (9)

Trigger

6 (8)

Output

Clock

Input

Gnd 7

1/2

MC3456

Modulation Input Voltage 5.0 V/cm

Clock Input Voltage

5.0 V/cm

Output Voltage

5.0 V/cm

Capacitor Voltage

5.0 V/cm

Figure 24. Sequential Timing Circuit

9.1 k

Threshold

V

CC

Reset

27 k 9.1 k

V

CC

Reset

27 k 50 k

V

CC

Reset

Control

Output

Load

GndGnd

Load

5.0

µ

F

0.001

µ

F

GndTrigger

Discharge

1.0

µ

F

Control

Output

0.01 µF

0.001 µF

Threshold

Threshold

Discharge

Trigger

5.0 µF

0.01

µ

F

Discharge

Trigger

Load

VCC (5.0 V to 15 V)

0.01

µ

F

Control

Output

1/2

MC3456

1/2

MC3456

1/2

MC3456

MC3456

9

MOTOROLA ANALOG IC DEVICE DATA

P SUFFIX

PLASTIC PACKAGE

CASE 646–06

ISSUE L

D SUFFIX

PLASTIC PACKAGE

CASE 751–05

(SO–14)
ISSUE N

OUTLINE DIMENSIONS

NOTES:

1. LEADS WITHIN 0.13 (0.005) RADIUS OF TRUE
POSITION AT SEATING PLANE AT MAXIMUM
MATERIAL CONDITION.

2. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.

3. DIMENSION B DOES NOT INCLUDE MOLD
FLASH.

4. ROUNDED CORNERS OPTIONAL.

17

14 8

B

A
F

HG D

K

C

N

L

J

M

SEATING
PLANE

DIM MIN MAX MIN MAX

MILLIMETERSINCHES

A 0.715 0.770 18.16 19.56
B 0.240 0.260 6.10 6.60
C 0.145 0.185 3.69 4.69
D 0.015 0.021 0.38 0.53
F 0.040 0.070 1.02 1.78
G 0.100 BSC 2.54 BSC
H 0.052 0.095 1.32 2.41
J 0.008 0.015 0.20 0.38
K 0.115 0.135 2.92 3.43
L 0.300 BSC 7.62 BSC
M 0 10 0 10
N 0.015 0.039 0.39 1.01

____

NOTES:

1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.

2. CONTROLLING DIMENSION: MILLIMETER.

3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.

5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.

SEATING
PLANE

14

58

C

K

4X P

A0.25 (0.010)MTB

SS

0.25 (0.010)MB

M

8X D

R

M

J

X 45

_

_

F

–A–

–B–

–T–

DIM MIN MAX MIN MAX

INCHESMILLIMETERS

A 4.80 5.00 0.189 0.196
B 3.80 4.00 0.150 0.157
C 1.35 1.75 0.054 0.068
D 0.35 0.49 0.014 0.019
F 0.40 1.25 0.016 0.049
G 1.27 BSC 0.050 BSC
J 0.18 0.25 0.007 0.009
K 0.10 0.25 0.004 0.009
M 0 7 0 7
P 5.80 6.20 0.229 0.244
R 0.25 0.50 0.010 0.019

____

G

MC3456

10

MOTOROLA ANALOG IC DEVICE DATA

Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty , representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “T ypical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
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MC3456/D

*MC3456/D*

◊