The **C555L-S08-R** is a low-power CMOS version of the industry-standard 555 timer Integrated Circuit (IC). It is widely used for generating accurate time delays or oscillations. ### 1. General Specifications The "C555L" indicates it is a CMOS variant, which offers significant advantages over the original bipolar (NE555) models, particularly regarding power consumption and input impedance. | Parameter | Specification | | :--- | :--- | | **Package Type** | SOP-8 (Surface Mount) | | **Supply Voltage (Vcc)** | 1.5V to 15V | | **Supply Current** | ~50µA to 250µA (Very low) | | **Maximum Frequency** | Up to 2 MHz | | **Output Drive** | Capable of sourcing/sinking current | | **Packaging** | Tape & Reel (indicated by the "-R") | --- ### 2. Pin Configuration (SOP-8) The device follows the standard 8-pin layout for 555 timers: | Pin # | Name | Description | | :--- | :--- | :--- | | 1 | **GND** | Ground reference (0V). | | 2 | **TRIG** | Trigger input; initiates the timing cycle when voltage < 1/3 Vcc. | | 3 | **OUT** | Output pin; pushes/pulls current to the load. | | 4 | **RESET** | Active low; resets the timer regardless of other inputs. | | 5 | **CONT** | Control voltage; allows access to the internal voltage divider. | | 6 | **THRES** | Threshold input; ends the timing cycle when voltage > 2/3 Vcc. | | 7 | **DISCH** | Discharge pin; used to discharge the timing capacitor. | | 8 | **VCC** | Positive supply voltage. | --- ### 3. Key Electronic Features #### A. CMOS Technology Unlike the original NE555, the C555L uses CMOS transistors. This results in: * **High Input Impedance:** Trigger and Threshold currents are in the pico-ampere (pA) range. * **Rail-to-Rail Output:** The output voltage can swing closer to the supply and ground rails. * **No Supply Spikes:** CMOS versions do not produce the large current "glitches" during output transitions that bipolar 555s do, reducing the need for large decoupling capacitors. #### B. Functional Modes The part can be configured in three primary modes: 1. **Monostable:** One-shot mode. Produces a single pulse of a fixed duration. 2. **Astable:** Free-running mode. Produces a continuous square wave (oscillator). 3. **Bistable:** Schmitt trigger mode. Acts as a flip-flop. --- ### 4. Part Number Breakdown The suffixing follows standard manufacturer nomenclature: * **C555L:** CMOS 555 Low Power series. * **S08:** SOP-8 (Small Outline Package, 8 pins). * **R:** Tape & Reel packaging for automated PCB assembly. ---