ADC (Analog-to-Digital Converter)

Purpose: Converts continuous analog signals into discrete digital values.

Key Parameters:

• Resolution: Number of bits (e.g., 8, 10, 12, 16-bit)
• Sampling Rate: Maximum conversion frequency (SPS – samples per second)
• Input Voltage Range: Min/Max analog input (e.g., 0–3.3V, ±5V)
• Reference Voltage (Vref): Precision voltage used for comparison
• Interface: SPI, I²C, parallel, or serial

Common Types:

• SAR ADC: Successive Approximation Register – medium speed, high accuracy
• Delta-Sigma (ΔΣ): High resolution, low noise, slower
• Flash ADC: Very fast, lower resolution, power-hungry
• Pipeline ADC: High speed, moderate power and complexity

Applications: Sensors, audio processing, data acquisition, instrumentation.

Design Tips:

• Use stable, low-noise Vref
• Bypass analog and digital supplies with 0.1µF caps
• Separate analog and digital grounds (AGND/DGND), join at single point
• Minimize trace length on analog inputs
• Use anti-aliasing filter before ADC input