555 Timer IC Specifications

General

• Type: Precision timer IC
• Modes: Astable, Monostable, Bistable
• Packages: DIP-8, SOIC-8, TSSOP
• Output Type: TTL-compatible digital output
• Functions: Pulse generation, oscillators, PWM, delays, timers

Electrical Characteristics

Operating Voltage

• NE555 / LM555: 4.5 V – 15 V
• CMOS 555 (TLC555): 2 V – 15 V

Supply Current

• NE555: 3–15 mA
• CMOS TLC555: < 1 mA

Output Current

• NE555: Up to 200 mA (sink or source)
• CMOS TLC555: ~10–50 mA depending on variant

Input Threshold

• Trigger Level: ~1/3 VCC
• Threshold Level: ~2/3 VCC

Switching

• Frequency Range: Up to ~500 kHz (NE555), up to ~2 MHz (CMOS TLC555)
• Rise/Fall Time: ~100 ns

Timing Characteristics

• Accurate timing using external resistor (R) and capacitor (C)
• Timing Range: microseconds to hours
• Duty Cycle: Adjustable via external components
• Temperature Stability: ~50 ppm/°C (typical)

Pins

1. GND
2. TRIG – Trigger
3. OUT – Output
4. RESET – Reset (active LOW)
5. CTRL – Control voltage (optional)
6. THR – Threshold
7. DISCH – Discharge
8. VCC – Power

Absolute Maximum Ratings

• Supply Voltage: 18 V (NE555)
• Output Current: 225 mA max
• Operating Temperature: 0°C to +70°C (commercial grade)

Applications

• PWM controllers
• Timers and delays
• LED flashers and beepers
• Oscillators and tone generators
• Frequency generation
• Relay and motor control circuits
• Pulse shaping and debouncing