Type 556 Dual Timer
The 556 Integrated circuit chip consists of two 555 timers in one
14-pin package. Refer to the 555 timer
information for details of operation.
Here are the pinouts for the 556 IC:
+----
----+
Discharge A |1 -- 14| VCC
Threshold A |2 13|
Discharge B
Control A |3
12| Threshold B
Reset A |4
556 11| Control B
Output A |5
10| Reset B
Trigger A |6
9| Output B
GROUND |7
8| Trigger B
+----------+
Correspondence between pins on the 555 timer and the 556 dual timer:
555 PIN
556 PINS
----------- ----------------
1 GROUND 7 GROUND
2 Trigger 6, 8
Triggers
3 Output 5,
9 Outputs
4 Reset 4,
10 Resets
5 Control 3,
11 Controls
6 Threshold 2,
12 Thresholds
7 Discharge 1,
13 Discharges
8 VCC 14
VCC