NE555DR timer (SOIC-8): specs and pinout
A Texas Instruments NE555 precision timer in an 8-pin SOIC surface-mount package (NE555DR is TI's tape-and-reel D package). With one resistor and capacitor it makes a monostable pulse, and with two resistors and a capacitor an astable oscillator.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage (VCC) | 4.5 V to 16 V | source Recommended Operating Conditions |
| Output current | Sink or source up to 200 mA | source Recommended Operating Conditions |
| Supply current at VCC = 5 V, no load | 3 mA typical, 6 mA max (output low); 2 mA typical, 5 mA max (output high) | source Electrical Characteristics |
| Operating ambient temperature | 0 C to 70 C | source Recommended Operating Conditions |
| Trigger level | About one-third of supply voltage; threshold level about two-thirds | source Description |
| Package | D (SOIC, 8) for NE555DR | source Device Information; Packaging Information |
Power
| Value | Source | |
|---|---|---|
| Supply | 4.5 V to 16 V | source Electrical Characteristics |
| Current | 2 to 3 mA typical at 5 V, no load | source Electrical Characteristics |
Pinout
This is a bare SOIC-8 chip, not a module. NE555DR is the part number TI uses for this tape-and-reel package. A surface-mount chip needs a SOIC-to-DIP adapter or careful soldering before it can be used on a breadboard.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| GND (1) | Ground | 0 V | source Pin Configuration and Functions | |
| TRIG (2) | Start of timing input | TRIG below one-third of CONT voltage sets output high | source Pin Configuration and Functions | |
| OUT (3) | Output | source Pin Configuration and Functions | ||
| RESET (4) | Active-low reset | Forces output and discharge low | source Pin Configuration and Functions | |
| CONT (5) | Control voltage | Sets comparator thresholds | source Pin Configuration and Functions | |
| THRES (6) | End of timing input | source Pin Configuration and Functions | ||
| DISCH (7) | Open-collector discharge output | Discharges the timing capacitor | source Pin Configuration and Functions | |
| VCC (8) | Supply | 4.5 V to 16 V | source Pin Configuration and Functions |
Build with it
Project ideas for the NE555DR timer (SOIC-8). Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- LED flasher with adjustable rate: The Uno's 5 V is inside the 4.5 V to 16 V supply range. The astable rate depends on the resistors and capacitor, and a series resistor limits LED current well under the 200 mA output rating. This is a surface-mount SOIC-8 chip, so the project is an SMD-soldering exercise and the chip is not breadboard-ready as supplied. Learning project.
- Pushbutton-free monostable pulse timer: A resistor, potentiometer and capacitor set the pulse length in monostable mode. Power from the Uno's 5 V, since the chip needs at least 4.5 V. Pull trigger pin 2 low from an Uno pin to start each pulse. This is a surface-mount SOIC-8 chip, so the project is an SMD-soldering exercise and the chip is not breadboard-ready as supplied. Learning project.
- A 555 astable clock and look at its waveform on a pocket oscilloscope: The Uno's 5 V pin powers the timer (4.5 V to 16 V range) and the output is probed with the oscilloscope to see how the resistors and capacitor set frequency and duty cycle. This is a surface-mount SOIC-8 chip, so the project is an SMD-soldering exercise and the chip is not breadboard-ready as supplied. Learning project.
Common mistakes
- Running it from 3.3 V: the minimum supply is 4.5 V (source: link, Recommended Operating Conditions)
- Leaving RESET or other unused inputs floating: the datasheet says to tie unused inputs to a defined level (source: link, Description)
- Asking for more than 200 mA from OUT: the rated output current is 200 mA maximum (source: link, Recommended Operating Conditions)
Not covered by the official source
- Values are for the VCC = 5 V rows of the supply-current table.
- No SOIC adapter is sold here; the ideas are SMD-soldering exercises.
Sources
- link (NA555/NE555/SA555/SE555 datasheet SLFS022K, Sept 1973, revised March 2026, Texas Instruments). NE555DR is TI's orderable part number, so TI is used as maker.