ADC/DAC

AD7124-8ASDZ

AD7124-8ASDZ - 24-Bit 8-Ch Sigma-Delta ADC | Analog Devices

The Analog Devices AD7124-8ASDZ is a 24-bit, 8-channel low-noise sigma-delta ADC analog front end with an integrated programmable gain amplifier and precision reference, supporting output data rates from 1.17 SPS up to 19.2 kSPS for high precision measurement applications. The part is offered with an AEC-Q100 qualified W grade for automotive use. A sigma-delta ADC (Sigma-Delta analog-to-digital converter) is a type of precision data converter that oversamples the analog input and uses digital filtering to achieve very high resolution and linearity. Within the signal chain hierarchy, it sits between the analog sensor front end and the digital processing block, making it a core component of any precision measurement system. Fully integrated analog front ends such as the AD7124-8 combine the converter, PGA, reference, and excitation current sources in a single device. Key features include a low-noise 24-bit sigma-delta core, eight analog input channels configurable as differential, pseudo-differential, or single-ended inputs, an embedded programmable gain amplifier, a precision low-drift internal band gap reference, and support for an externally buffered differential reference. Simultaneous 50 Hz and 60 Hz line rejection is achieved at 25 SPS (single-cycle settling), with rejection in excess of 80 dB at lower output data rates, per the manufacturer datasheet. The AD7124-8 establishes one of the highest degrees of signal chain integration available in precision data acquisition: excitation current sources (IOUT) and input bias (VBIAS) functions can even share AIN pins, per Analog Devices EngineerZone FAQs, reducing external component count in sensor systems. Digital communication is handled over a standard SPI serial interface, and register-based configuration enables per-setup filtering and reference selection across its eight setup configurations. Typical applications include industrial process control (RTD and thermocouple temperature measurement), medical patient monitoring and diagnostics, weigh scales, and precision laboratory instrumentation - all domains where microvolt-level noise and high linearity directly determine system accuracy. The device family targets industrial, medical, and test and measurement markets per Analog Devices product documentation. A key design consideration: output data rate trades directly against noise performance and settling time. Operating at 25 SPS single-cycle setting gives best 50/60 Hz rejection, while 19.2 kSPS operation suits faster multiplexed channel scanning; verify filter selection per setup in the configuration registers. This page synthesizes verified distributor data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.