Analog Devices Inc. AD7124-4BCPZ

Overview

AD7124-4BCPZ from Analog Devices is a 24-bit sigma-delta ADC with integrated PGA, reference, excitation currents, and diagnostics-designed for high-precision sensor measurement. It supports 4 differential or 7 pseudo-differential inputs, offers three power modes (255 µA/355 µA/930 µA typical), delivers 24 nV rms noise at 1.17 SPS (gain = 128), and operates across −40°C to +125°C in a 32-lead LFCSP package.

For engineers reviewing the AD7124-4BCPZ datasheet, AD7124-4BCPZ pinout, AD7124-4BCPZ application, or AD7124-4BCPZ equivalent, key selection criteria include simultaneous 50/60 Hz rejection at 25 SPS, per-channel configuration support, internal 10 ppm/°C reference drift, rail-to-rail analog input capability for gains > 1, and integrated diagnostics enabling SIL-certifiable system design.

Technical Context

The AD7124-4BCPZ implements a multi-stage sigma-delta modulator with programmable sinc4/sinc3/fast-settling/post filters, enabling configurable trade-offs between noise, settling time, and 50/60 Hz rejection. Its on-chip PGA (gain 1–128) and matched excitation current sources (0.1–1000 µA) allow direct interface to RTDs, thermocouples, and bridge sensors without external signal conditioning.

Diagnostics include CRC-protected register access, reference detect, power supply monitoring (ALDO/DLDO), AIN over/undervoltage detection, burnout current control, and temperature sensor readback-all coordinated via an automatic channel sequencer supporting up to 16 channels (analog + diagnostic). The device uses either internal 614.4 kHz oscillator or external clock, with SPI/QSPI/MICROWIRE-compatible 3-/4-wire serial interface and Schmitt-triggered SCLK.

Key Specifications

Pinout & Package

AD7124-4BCPZ is housed in a 32-lead, 5 mm × 5 mm × 0.75 mm LFCSP package with exposed thermal pad. Pin functions are validated per Analog Devices AD7124-4 Rev. E datasheet (pages 15–17).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision sigma-delta ADC applications.

Compared with AD7124-8BCPZ, the AD7124-4BCPZ saves board space and BOM cost in 4-channel systems; compared with LTC2499CGN#PBF, it reduces design complexity and improves system-level accuracy by integrating PGA, reference, excitation, and diagnostics-making it optimal for certified industrial transmitters.

Availability

AD7124-4BCPZ is available at Aetrix Electronics and suitable for industrial process control, smart transmitter development, and high-reliability temperature/pressure measurement requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7124-4BCPZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7124 family was designed specifically for high-precision, low-power sensor measurement in harsh industrial environments-integrating signal conditioning, conversion, diagnostics, and power management into a single IC to simplify certified system design.

FAQ

What is the maximum output data rate of the AD7124-4BCPZ in full power mode?

The AD7124-4BCPZ supports a maximum output data rate of 19,200 SPS in full power mode. This rate is achievable with sinc3 or sinc4 filters and enables high-speed applications such as vibration monitoring or fast-loop control. At this rate, RMS noise increases to 23 nV rms (gain = 128), and current consumption rises to 930 µA typical. Filter selection and ODR must be configured via the ADC_CONTROL and FILTER registers.

Does the AD7124-4BCPZ include an internal voltage reference, and what is its accuracy?

Yes, the AD7124-4BCPZ integrates a precision band gap reference with 2.5 V nominal output, ±0.2% initial accuracy at 25°C, and maximum drift of 10 ppm/°C over −40°C to +125°C (LFCSP package). It supplies 70 µA and features 85 dB PSR. The reference can be used internally or buffered for external circuits. External references (0.5–AVDD V) are also supported with buffered/unbuffered options.

How many analog input channels does the AD7124-4BCPZ support, and how are they configured?

The AD7124-4BCPZ supports up to four fully differential analog inputs (AIN0–AIN3) or seven pseudo-differential inputs using shared AINx pins. Configuration is done per channel via eight independent setup registers, each defining gain (1–128), filter type, output data rate, buffering, and reference source. The automatic channel sequencer manages conversions across enabled channels-including diagnostics-without host intervention.

What diagnostic functions are built into the AD7124-4BCPZ, and how do they support functional safety?

The AD7124-4BCPZ includes CRC-protected register access, reference detect, power supply monitors (ALDO/DLDO), AIN over/undervoltage detection, burnout current control, and memory checksums. These features collectively enable >90% safe failure fraction (SFF) per IEC 61508. Diagnostics run autonomously or on-demand, reducing software validation burden and eliminating need for external watchdogs or reference buffers in SIL2-capable designs.

What package type and thermal characteristics apply to the AD7124-4BCPZ?

The AD7124-4BCPZ is supplied in a 32-lead LFCSP package (5 mm × 5 mm × 0.75 mm) with exposed thermal pad. Its thermal resistance θ_JA is 36°C/W (JEDEC standard board), and θ_JC is 5.5°C/W. The package supports −40°C to +125°C operation and is RoHS-compliant. Pin compatibility with AD7124-4 variants is maintained within the same package family, but AD7124-4BCPZ is not pin-compatible with the TSSOP version.