Order this document by MC3456/D
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.
DUAL TIMING CIRCUIT
SEMICONDUCTOR
TECHNICAL DATA
• Direct Replacement for NE556/SE556 Timers
• Timing from Microseconds through Hours
• Operates in Both Astable and Monostable Modes
• Adjustable Duty Cycle
P SUFFIX
PLASTIC PACKAGE
CASE 646
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–14)
• 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
PIN CONNECTIONS
1
2
3
14
Discharge A
Threshold A
V
CC
13
12
Discharge B
Figure 1. 22 Second Solid State Time Delay Relay Circuit
Control A
Reset A
Output A
Trigger A
Gnd
Threshold B
Control B
Reset B
4
5
6
7
11
10
9
1.0 k
Load
MT2
3
8
Output B
Trigger B
MT1
6
G
4
2
10 k
R
20 M
C
1/2
MC3456
8
7
5
F
(Top View)
1.0 µF
0.1 µF
0.01
µ
1
1N4003
–10 V
ORDERING INFORMATION
Operating
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).
1N4740
10
+
µF
Temperature Range
Device
MC3456P
NE556D
Package
Plastic DIP
SO–14
0° to +70°C
Figure 3. General Test Circuit
V
CC
I
CC
V
R
Figure 2. Block Diagram (1/2 Shown)
Reset
4
8
700
V
CC
14
7
5
V
CC
+
F
Control
Voltage
0.01
µ
Discharge
1/2
5 k
MC3456
1 (13)
2 (12)
Threshold
3
Threshold
6
Discharge
Output
+
V
Comp
S
Flip
Flop
2.0 k
Output
3 (11)
Control Voltage
I
A
th
R
S
–
Gnd
1
Trigger
I
I
V
Sink
O
Q
2
5 k
5 k
Source
5 (9)
Inhibit/
Reset
+
Comp
B
6 (8)
Trigger
–
Test circuit for measuring DC parameters (to set output and measure parameters):
a) When V
b) When V
2/3 V , V is low.
S
S
CC O
1/3 V , V is high.
CC
O
7
4 (10)
Reset
c) When V is low, Pin 7 sinks current. To test for Reset, set V high,
O
O
Gnd
c) apply Reset voltage, and test for current flowing into Pin 7. When Reset
c) is not in use, it should be tied to V
.
CC
Motorola, Inc. 1996
Rev 2
1
MOTOROLA ANALOG IC DEVICE DATA