Last Updated on March 16, 2024
Simple Analog to Digital Converter Circuit using Timer IC 555 designed with few external components. As we know converting Analog signal in to digital form includes different stages and depends on the output resolution cost of the converter circuit increase. If you are looking for low resolution (4 bit to 10 bit) ADC then this circuit might help you.
One of the simplest and cost-effective ways to create an Analog-to-Digital converter (ADC) is by utilizing the versatile Timer IC 555. Here the timer IC takes Analog input through Discharge and Threshold, Trigger Pins. The output pulse width is proportional to the difference between the analog input voltage and the voltage across the 1µF capacitor (C1).
Circuit Diagram
Components Required
| 1 | C2 | 0.1µF | C_Disc_D3.0mm_W1.6mm_P2.50mm | 1 | ||
| 2 | C1 | 1µF | C_Radial_D4.0mm_H5.0mm_P1.50mm | 1 | ||
| 3 | R1, R4 | 100Ω | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | 2 | ||
| 4 | R2 | 330Ω | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | 1 | ||
| 5 | R3 | 430Ω | R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_Horizontal | 1 | ||
| 6 | U1 | LM555 | DIP-8_W7.62mm | 1 | ||
| 7 | Q1 | BC547 | TO-92_Inline | 1 | ||
| 8 | J1, J2, J3 | Screw_Terminal_01x02 | TerminalBlock_Altech_AK300-2_P5.00mm | 3 |
Construction & Working
As we know The process of converting an analog signal into its digital counterpart involves sampling the analog signal at regular intervals and quantizing the sampled values into a digital code. But this circuit gives digital pulse with variable duty cycle depend on analog input signal.
Charging and Discharging of Timing capacitor C1 occurs depends on the analog input signal hence the output from the timer IC varies in accordance to the analog signal. Here Transistor Q1 acts as switch and inverts digital output.
The Analog to Digital Converter Circuit using the Timer IC 555 is a simple yet effective method of converting analog signals into digital form for low level applications and you can improve it by using operational amplifier and implementing successive approximation method.
Here is the simulation result given. Input analog signal amplitude is 8V and operating voltage of circuit is 8V DC.
Simulation Output
Printed Circuit Board
Analog to Digital Converter Circuit using Timer IC 555 PCB Gerber Files.
Interactive Board Viewer
