Features and Benefits

  • Throughput: 1.8 MSPS maximum
  • INL: ±3.1 ppm maximum
  • Guaranteed 20-bit no missing codes
  • Low power
    • 9.0 mW at 1.8 MSPS (VDD only)
    • 83 μW at 10 kSPS, 15 mW at 1.8 MSPS (total)
  • SNR: 100.5 dB typical at 1 kHz, 99 dB typical at 100 kHz
  • THD: −123 dB typical at 1 kHz, −100 dB typical at 100 kHz
  • Ease of use features reduce system power and complexity
    • Input overvoltage clamp circuit
    • Reduced nonlinear input charge kickback
    • High-Z mode
    • Long acquisition phase
    • Input span compression
    • Fast conversion time allows low SPI clock rates
    • SPI-programmable modes, read/write capability, status word
  • Differential analog input range: ±VREF
    • 0 V to VREF with VREF between 2.4 V to 5.1 V
  • Single 1.8 V supply operation with 1.71 V to 5.5 V logic interface
  • SAR architecture: no latency/pipeline delay
  • Guaranteed operation: −40°C to 125°C
  • Serial interface SPI-/QSPI-/MICROWIRE-/DSP-compatible
  • Ability to daisy-chain multiple ADCs and busy indicator
  • 10-lead packages: 3 mm × 3 mm LFCSP, 3 mm × 4.90 mm MSOP

Product Details

The AD4020 is a low noise, low power, high speed, 20-bit, 1.8 MSPS precision successive approximation register (SAR) analog-to-digital converter (ADC). It incorporates ease of use features that lower the signal chain power, reduce signal chain complexity, and enable higher channel density. The high-Z mode, coupled with a long acquisition phase, eliminates the need for a dedicated high power, high speed ADC driver, thus broadening the range of low power precision amplifiers that can drive this ADC directly, while still achieving optimum performance. The input span compression feature enables the ADC driver amplifier and the ADC to operate off common supply rails without the need for a negative supply while preserving the full ADC code range. The low serial peripheral interface (SPI) clock rate requirement reduces the digital input/output power consumption, broadens processor options, and simplifies the task of sending data across digital isolation.

Operating from a 1.8 V supply, the AD4020 has a ±VREF fully differential input range with VREF ranging from 2.4 V to 5.1 V. The AD4020 consumes only 15 mW at 1.8 MSPS with a minimum SCK rate of 71 MHz in turbo mode and achieves ±3.1 ppm integral nonlinearity (INL), guaranteed no missing codes at 20 bits with 100.5 dB typical signal-to-noise ratio (SNR). The reference voltage is applied externally and can be set independently of the supply voltage.

The SPI-compatible versatile serial interface features seven different modes including the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus, and provides an optional busy indicator. The AD4020 is compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply.

The AD4020 is available in a 10-lead MSOP or a 10-lead LFCSP with operation specified from −40°C to +125°C. The device is pin compatible with the 18-bit, 2 MSPS AD4003.


  • Automatic test equipment
  • Machine automation
  • Medical equipment
  • Battery-powered equipment
  • Precision data acquisition systems

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

Software & Systems Requirements

Tools & Simulations

IBIS Models

AD4000 Series IBIS Models

Design Tools

Precision ADC Driver Tool

Use the Precision ADC Driver Tool to simulate the performance of precision ADC and driver combinations.

Reference Designs (1)

Product Recommendations

AD4020 Companion Parts

Recommended Driver Amplifiers

Recommended External Voltage References

Recommended Digital Isolators

  • For SPI Interface, low power, high-speed 3/3.5 kVrms isolation: ADUM141D, ADUM141E.

Recommended Low Dropout Regulators and Switchers

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.


AD4020 Discussions

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Evaluation Boards Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.