Semiconductor Components Industries, LLC, 2004
March, 2004 Rev. 8
1
Publication Order Number:
MC1455/D
MC1455, MC1455B,
NCV1455B
Timers
The MC1455 monolithic 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, time is precisely controlled by one external resistor and
capacitor. For astable operation as an oscillator, the freerunning
frequency and the duty cycle are both accurately controlled with two
external resistors and one capacitor. 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 NE555 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
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P1 SUFFIX
PLASTIC PACKAGE
CASE 626
1
8
D SUFFIX
PLASTIC PACKAGE
CASE 751
xx
A
WL, L
YY, Y
WW, W = Work Week
8
1
MARKING
DIAGRAMS
XXXXXXXXX
AWL
YYWW
XXXXXX
ALYW
1
8
See detailed ordering and shipping information in the package
dimensions section on page ___ of this data sheet.
(Create Named OrderingInfoText.)
ORDERING INFORMATION
= Specific Device Code
= Assembly Location
= Wafer Lot
= Year
Figure 1. 22 Second Solid State Time Delay Relay Circuit
Figure 2. Representative Block Diagram
Figure 3. General Test Circuit
1.0 k
Load
MT2
10 k
0.1 F
0.01 F
1
5
2
4
3
8
6
7
1.0 F
C
20M
G
MT1
10 V
1N4003
1
1N4740
3.5 k
250 V
10 F
+
t = 1.1; R and C = 22 sec
Time delay (t) is variable by
changing R and C (see Figure 16).
V
CC
Threshold
Control Voltage
Trigger
6
5
2
5 k
8
5 k
5 k
+
Comp
A
+
Comp
B
1
Gnd
Reset
4
R
S
Flip
Flop
Q
Inhibit/
Reset
7
3
Discharge
Output
R
MC1455
V
R
Reset
5
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 F
+
Control
Voltage
Output
V
CC
MC1455
Test circuit for measuring DC parameters (to set output and
measure parameters):
a) When V
S
2/3 V
CC
, V
O
is low.
b) When V
S
1/3 V
, V
is high.
c) When V
is low, Pin 7 sinks current. To test for Reset, set V
c)
high, apply Reset voltage, and test for current flowing into Pin 7.
c)
When Reset is not in use, it should be tied to V
CC
.
