TLC555 Pinout
TLC555 CMOS Timer · CMOS version of the 555 timer: same pinout, much lower supply current, higher frequency, rail-to-rail-ish output.
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | TRIG | Input | Trigger (fires when below 1/3 VDD) |
| 3 | OUT | Output | Output |
| 4 | RESET | Control | Reset (active-low; tie to VDD if unused) |
| 5 | CTRL | Control | Control voltage (tie via 10nF to ground if unused) |
| 6 | THRES | Input | Threshold (flips when above 2/3 VDD) |
| 7 | DISCH | Output | Discharge (to timing capacitor) |
| 8 | VDD · VCC | Power | Supply + (2–15V) |
How to read the TLC555 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
Can the TLC555 replace an NE555 directly?
In most timing circuits, yes — the pinout is identical. The TLC555 draws far less supply current and reaches higher frequencies, but its output drive is weaker, so re-check the load if you were relying on the NE555 ~200mA capability.
Why choose CMOS over the classic NE555?
Lower power (microamps of quiescent current vs milliamps), higher max frequency, lower supply voltage, and much smaller supply-current spikes on output transitions (less power-rail noise).
Pinout data comes from TI TLC555 datasheet (standard DIP-8 numbering). Refer to the actual device datasheet as authoritative for the pinout.