NE556 Pinout
NE556 Dual Timer · Dual 555 timer; one chip replaces two NE555s, sharing supply/ground.
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | 1DISCH | Output | Timer 1 discharge |
| 2 | 1THRES | Input | Timer 1 threshold |
| 3 | 1CTRL | Control | Timer 1 control voltage |
| 4 | 1RESET | Control | Timer 1 reset (active-low) |
| 5 | 1OUT | Output | Timer 1 output |
| 6 | 1TRIG | Input | Timer 1 trigger |
| 7 | GND | GND | Ground (shared by both timers) |
| 8 | 2TRIG | Input | Timer 2 trigger |
| 9 | 2OUT | Output | Timer 2 output |
| 10 | 2RESET | Control | Timer 2 reset (active-low) |
| 11 | 2CTRL | Control | Timer 2 control voltage |
| 12 | 2THRES | Input | Timer 2 threshold |
| 13 | 2DISCH | Output | Timer 2 discharge |
| 14 | VCC | Power | Supply + (4.5–15V, shared by both timers) |
How to read the NE556 pinout
- 01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
- 02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
- 03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.
Frequently asked questions
Is the NE556 the same as two NE555s?
Functionally equivalent: internally it is two independent 555s sharing pin 7 GND and pin 14 VCC, saving board space.
How do the pins map to the 555?
Timer 1 is on the left half (1–6) and timer 2 on the right half (8–13); each group has TRIG/THRES/OUT/RESET/CTRL/DISCH with the same meaning as a single 555.
Pinout data comes from TI NE556 datasheet (standard DIP-14 numbering). Refer to the actual device datasheet as authoritative for the pinout.