2.1-MHz, 250-µA, Low-Power Timer - TLC555


2.1-MHz, 250-µA, Low-Power Timer



The TLC555 is a monolithic timing circuit fabricated using the TI LinCMOS™ process. The timer is fully compatible with CMOS, TTL, and MOS logic, and operates at frequencies up to 2 MHz. Because of its high input impedance, this device uses smaller timing capacitors than those used by the NE555. As a result, more accurate time delays and oscillations are possible. Power consumption is low across the full range of power-supply voltage.

Like the NE555, the TLC555 has a trigger level equal to approximately one-third of the supply voltage and a threshold level equal to approximately two-thirds of the supply voltage. These levels can be altered by use of the control voltage terminal (CONT). When the trigger input (TRIG) falls below the trigger level, the flip-flop is set and the output goes high. If TRIG is above the trigger level and the threshold input (THRES) is above the threshold level, the flip-flop is reset and the output is low. The reset input (RESET) can override all other inputs and can be used to initiate a new timing cycle. If RESET is low, the flip-flop is reset and the output is low. Whenever the output is low, a low-impedance path is provided between the discharge terminal (DISCH) and GND. All unused inputs must be tied to an appropriate logic level to prevent false triggering.


  • Very Low Power Consumption:
    • 1 mW Typical at VDD = 5 V
  • Capable of Operation in Astable Mode
  • CMOS Output Capable of Swinging Rail to Rail
  • High Output Current Capability
    • Sink: 100 mA Typical
    • Source: 10 mA Typical
  • Output Fully Compatible With CMOS, TTL, and MOS
  • Low Supply Current Reduces Spikes During Output Transitions
  • Single-Supply Operation From 2 V to 15 V
  • Functionally Interchangeable With the NE555; Has Same Pinout
  • ESD Protection Exceeds 2000 V Per MIL-STD-883C, Method 3015.2
  • Available in Q-Temp Automotive
    • High-Reliability Automotive Applications
    • Configuration Control and Print Support
    • Qualification to Automotive Standards

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Parametrics Compare all products in Timers

Frequency (Max) (MHz)
VCC (Min) (V)
VCC (Max) (V)
Iq (Typ) (uA)
Operating Temperature Range (C)
Approx. Price (US$)
TLC555 LMC555 LMC555-MD8 NE555 TLC555-Q1
2.1    3    3    0.1    2.1   
2    1.5    1.5    4.5    2   
15    15    15    16    15   
250    50    50    2000    170   
Catalog    Catalog    Military    Catalog    Automotive   
-40 to 85
-40 to 125
0 to 70   
-40 to 125
-40 to 85   
-55 to 125    0 to 70    -40 to 125   
0.22 | 1ku    0.37 | 1ku      0.07 | 1ku    0.29 | 1ku   

Other qualified versions of TLC555

Version Part Number Definition
Military TLC555M QML certified for Military and Defense Applications
Automotive TLC555-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects

Related end equipment

  • Precision Timing
  • Pulse Generation
  • Sequential Timing
  • Time Delay Generation
  • Pulse Width Modulation
  • Pulse Position Modulation
  • Linear Ramp Generator

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