ADC—Analog-to-digital converter technology and architecture

Successive Approximation Register (SAR) vs. Delta‑Sigma: Choosing the right architecture for your next‑generation design.

Glowing microchip on a circuit board

CSEM delivers highly customizable ADC IP solutions designed to meet the precision, speed, and efficiency demands of medical devices, industrial sensors, test equipment, and consumer electronics. Our deep expertise in both SAR and Delta‑Sigma architectures allows you to balance performance and constraints, ensuring your design achieves the best results for its intended application.

Modern precision applications require increasingly sophisticated analog‑to‑digital conversion. The rise of smart sensors on the one hand, and low‑power electronics on the other, requires converters that reliably bridge the analog and digital worlds. At CSEM, we combine advanced SAR and Delta‑Sigma technologies—each optimized for specific performance and power constraints—to deliver tailored ADC IP that works reliably across a range of environments and use cases.

Delta‑Sigma ADCs: High precision for demanding applications

Delta‑Sigma (ΔΣ) converters excel in precision‑driven environments such as medical instrumentation, test equipment, and audio electronics. They use advanced oversampling and noise‑shaping techniques to deliver highly accurate digital representations of analog signals, making them ideal where precision and low noise matter most.

Why choose a Delta‑Sigma ADC?

  • High resolution: Provides 12–20‑bit precision for capturing fine signal details.
  • Low noise: Oversampling and noise‑shaping reduce distortion and deliver clean, accurate data.
  • Integrated anti‑aliasing: Simplifies design by removing the need for external analog filters.
  • Wide dynamic range: Up to 113 dB, allowing accurate measurement of both small and large signals.
  • Robust temperature range: Operates reliably from –40 °C to +125 °C, making it suitable for harsh environments.
  • Low power consumption: Maintains efficiency even at higher sampling rates (up to 768 kS/s), making it ideal for battery‑powered and IoT applications.

SAR ADCs: A smart balance between speed and efficiency

Successive Approximation Register (SAR) ADCs offer an ideal balance between conversion speed, precision, and low‑power operation. They are predominantly digital, making them stable across temperatures and ideal for cost‑sensitive applications.

Why choose a SAR ADC?

  • Speed: Support sampling rates of up to 100 MS/s, making them ideal for moderate‑speed and time‑sensitive applications.
  • High resolution: Deliver precision from 8–14 bits, covering the needs of most industrial and portable measurement tasks.
  • Power efficiency: Scale energy usage with sampling rate, reducing consumption by up to 50% at lower speeds—ideal for battery‑powered devices.
  • Robust architecture: Predominantly digital design delivers stable performance across temperatures and process variations.
  • Modern CMOS compatibility: Operate reliably across CMOS nodes from 22 nm to 180 nm, allowing for seamless integration into a wide range of products.

Scatter plot comparing the performance of Delta-Sigma (ΔΣ) and Successive Approximation Register (SAR) ADCs. It highlights the trade-off between resolution (ENOB) and signal bandwidth, with ΔΣ ADCs excelling in high-precision, low-bandwidth applications and SAR ADCs in high-speed, moderate-resolution tasks.

Block diagram illustrating the architecture of a high-performance Delta-Sigma (ΔΣ) analog-to-digital converter (ADC) system. The upper section represents the main signal processing chain. The lower section details the internal modulator core, highlighting enhancement techniques such as dynamic weighted averaging, dither injection, and feedback DAC integration.

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Make the right choice for your design

Leverage CSEM’s precision engineering, deep expertise, and decades of experience across medical, industrial, test, and consumer electronics. Connect with our team and build the right ADC solution for your next‑generation design.

Why this matters?

In industries where measurement precision impacts patient outcomes, equipment reliability, or product quality, selecting the right ADC architecture is critical. SAR and Delta‑Sigma converters each have distinct benefits. At CSEM, we design both, ensuring you obtain the ideal solution tailored to your application.

SAR vs. Delta‑Sigma: A Comparison

Delta‑Sigma and SAR ADCs each have strengths. The lists below provide a quick view of their characteristics and ideal use cases.

SAR ADC

  • Best-suited applications: Moderate‑speed data acquisition, sensor interfaces, industrial and portable test equipment
  • Integration: CMOS‑friendly (22–180 nm)
  • Effective number of bits (ENOB): 8–14 bits
  • Sampling rate: Up to ~100 MS/s
  • Dynamic range: Moderate (suitable for general industrial requirements)
  • Signal bandwidth: Up to 50 MHz
  • Power efficiency: Low, scales with sample rate
  • Architecture: Simple, predominantly digital design
  • Temperature operating range: –40 °C to 85 °C (requires design consideration)
  • Why Choose It?: Best for moderate‑speed, low‑power, cost‑sensitive applications

Delta‑Sigma ADC

  • Best-suited applications: High‑precision measurement, medical devices, audio processing
  • Integration: CMOS‑friendly (22–180 nm)
  • Effective number of bits (ENOB): 12–20 bits
  • Sampling rate: Up to ~768 kS/s
  • Dynamic range: High (113 dB range), ideal for precision measurement
  • Signal bandwidth: Up to 384 kHz
  • Power efficiency: Low for precision but higher than SAR due to oversampling
  • Architecture: Complex with built‑in digital filtering and noise shaping
  • Temperature operating range: –40 °C to 125 °C
  • Why Choose It?: Best for maximum precision and accuracy where noise performance is critical

Let’s design the right ADC together

Let’s bring your next-generation design to life. From concept to integration, our experts support you with tailored ADC architectures that meet your technical and operational goals.