AD7124-4BRUZ - 24-Bit Sigma-Delta ADC with PGA | Analog Devices
MPN: AD7124-4BRUZ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.92 | $8.92 |
| 10 | $8.12 | $81.20 |
| 100 | $7.35 | $735.00 |
| 500 | $6.68 | $3,340.00 |
| 1,000 | $6.1 | $6,100.00 |
AD7124-4BRUZ Overview
A sigma-delta (Ξ£-Ξ) analog-to-digital converter is a type of ADC that oversamples the input signal and applies digital filtering to achieve very high resolution, typically 16 to 32 bits, making it the dominant architecture for precision measurement. Within the signal chain hierarchy, the AD7124-4 sits at the highest integration level: it combines the ADC, a programmable gain amplifier (PGA), a precision low-drift internal band gap reference, reference buffering, excitation current sources, and a flexible digital filter in a single power-management-friendly device.
Key features include the 24-bit resolution sigma-delta core, an integrated PGA that amplifies small sensor signals directly, an internal precision band gap reference that removes the need for an external reference in many designs, and a power mode architecture that lets designers trade current consumption against noise and speed. The device also accepts an external differential reference which can be internally buffered, further simplifying high-accuracy designs.
Architecturally, the AD7124-4 establishes a high degree of signal chain integration: the low-noise PGA, reference buffers, and digital filtering are all on-chip, so a thermocouple, RTD, or bridge sensor can often be connected directly to the analog input pins. The digital interface is a standard SPI-compatible serial port with a DOUT/RDY multifunction pin, allowing simple connection to any microcontroller. Multiple filter options allow output data rate and 50 Hz/60 Hz rejection to be tuned in firmware.
Typical applications include RTD and thermocouple temperature measurement, pressure and weigh-scale bridge transducers, process control analog inputs, portable instrumentation, and smart transmitters where low power and high resolution are simultaneously required.
A key design consideration is the power mode selection: the lowest power mode maximizes battery life but increases rms noise and reduces available output data rates, so noise versus power must be balanced per application.
This page synthesizes distributor sourcing data, verified drop-in alternatives, and practical design guidance not consolidated in the manufacturer datasheet.
Drop-in alternatives for AD7124-4BRUZ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
AD7124-8BRUZ
β Drop-Inπ Reference alternative (not in catalog)
MCP3564-E/ST
β Drop-Inπ Reference alternative (not in catalog)
ADS124S08IPBS
β Drop-Inπ Reference alternative (not in catalog)
AD7124-4BRUZ Maximum Ratings & Electrical Characteristics
| Resolution | 24 bit |
| Converter Type | Sigma-Delta (Ξ£-Ξ) |
| Number of ADCs | 1 |
| Differential Inputs | 4 |
| Single-Ended / Pseudo-Differential Inputs | 7 |
| Input Multiplexer Inputs | 7 |
| Integrated PGA | Yes |
| Internal Reference | Precision low-noise low-drift band gap |
| External Reference | Differential, internally bufferable |
| Power Modes | Multiple selectable power modes |
| Interface | SPI-compatible serial (DOUT/RDY) |
| Package | 24-TSSOP |
| Mounting Type | Surface Mount |
| Application | High precision measurement analog front end |
AD7124-4BRUZ 24-tssop Pin Configuration Guide
Pin configuration for AD7124-4BRUZ (24-tssop package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for AD7124-4BRUZ.
Refer to the datasheet for full pin configuration.
Typical Applications
AD7124-4BRUZ is suitable for 6 applications: RTD Temperature Measurement, Thermocouple Input Modules, Pressure Sensors and Weigh Scales, Process Control Analog Input Modules, Portable and Battery-Powered Instrumentation, Smart Transmitters.
RTD Temperature Measurement
The AD7124-4BRUZ fits RTD measurement because its integrated PGA amplifies the small ratiometric signal from a Pt100 or Pt1000 sensor while its precision low-drift internal band gap reference and bufferable external reference input preserve measurement accuracy. A ratiometric topology - sharing one excitation current between the RTD and the reference resistor - cancels current-source drift, and the AD7124-4 supports this directly with on-chip excitation and reference buffering per the Analog Devices datasheet. Placed at the sensor head with a digital filter configured for 50 Hz/60 Hz rejection, the 24-bit sigma-delta core resolves sub-0.1 C temperature steps. The main trade-off is conversion time: heavier filtering for noise rejection lowers the output data rate, so multiplexed multi-RTD systems must budget scan time per channel.
Recommended
Thermocouple Input Modules
Thermocouples generate tens of microvolts per degree C, so input noise directly limits resolution; the AD7124-4BRUZ addresses this with its low-noise PGA, 24-bit sigma-delta conversion, and selectable power modes that allow the designer to bias the device for minimum noise in thermally demanding environments. According to the Analog Devices datasheet, the device is a completely integrated analog front end, meaning cold-junction compensation inputs and the thermocouple channel can share the same 7-input multiplexer. The internal low-drift band gap reference removes a discrete reference from the BOM, while the SPI interface with DOUT/RDY simplifies connection to a module microcontroller. Designers should apply appropriate filtering ahead of the inputs since the PGA amplifies any external common-mode and differential noise together with the signal.
Recommended
Pressure Sensors and Weigh Scales
Bridge-type pressure sensors and load cells output differential signals in the millivolt range, which the AD7124-4BRUZ can digitize directly thanks to its integrated PGA and 4 differential input configurations. The differential, internally bufferable external reference input enables ratiometric bridge measurement, where supply drift affects the bridge and the reference identically and therefore cancels in the conversion result. Per the Analog Devices product documentation, the device's low noise and complete integration make it targeted at high precision measurement applications of exactly this class. In weigh-scale designs the digital filter can be programmed to reject 50 Hz/60 Hz mains interference and mechanical vibration. The design trade-off is settling time after multiplexer switching, which heavier sinc filters extend; system throughput must account for this.
Recommended
Process Control Analog Input Modules
PLC and DCS analog input modules must digitize multiple 4-20 mA current loops and voltage channels with high accuracy, and the AD7124-4BRUZ consolidates this function: its 7 multiplexed inputs, integrated PGA, precision internal reference, and flexible digital filter replace several discrete blocks in a traditional input channel. The selectable power modes let a 16-channel module balance loop scan rate against per-channel noise, and the SPI-compatible serial interface with a DOUT/RDY ready indication integrates cleanly with module firmware. According to the Analog Devices datasheet, the part was designed for high precision measurement front ends, which is precisely the PLC analog input role. Designers should verify channel settling across the multiplexer and protect inputs against industrial overvoltage events with external clamp networks.
Recommended
Portable and Battery-Powered Instrumentation
Handheld meters, data loggers, and battery-powered analyzers demand high resolution at very low average current, and the AD7124-4BRUZ serves both needs through its multiple selectable power modes. According to the Analog Devices product description, the device is a low power, low noise, completely integrated analog front end - the low power mode trades conversion speed and rms noise for dramatically reduced current consumption, ideal for duty-cycled sampling in portable designs. Integration of PGA, reference, and excitation sources reduces component count, board area, and quiescent budget simultaneously. In practice, designers run the device in the lowest power mode between samples and use the DOUT/RDY interrupt to wake the host microcontroller only when new data is ready, extending battery life while keeping 24-bit resolution available on demand.
Recommended
Smart Transmitters
4-20 mA smart transmitters for temperature and pressure require a precision ADC that consumes minimal loop power while maintaining calibration-grade accuracy, a combination the AD7124-4BRUZ delivers through its low power modes, low noise 24-bit sigma-delta core, and integrated precision reference. Because the entire analog front end - PGA, reference buffers, and digital filter - is on chip per the Analog Devices datasheet, transmitter designers can connect sensors directly and spend their power budget on the microcontroller and loop driver instead of analog conditioning. The register-configurable filter allows output rates and mains rejection to be tuned in firmware, supporting multi-sensor transmitter variants on one PCB. The key design consideration is ensuring the internal reference drift specification supports the transmitter's long-term accuracy class, or selecting the buffered external reference path for ratiometric sensors.
Recommended
Recommended Products Summary
Engineering reference data for AD7124-4BRUZ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7124-8BRUZ | MCP3564-E/ST | ADS124S08IPBS |
|---|---|---|---|---|
| Package | 24-TSSOP | 24-TSSOP - same | 24-TSSOP - same | 24-TSSOP - same |
| Brand | Analog Devices | Analog Devices | Microchip Technology | Texas Instruments |
| Resolution | 24 bit | 24 bit | 24 bit | 24 bit |
| Architecture | Sigma-Delta (Ξ£-Ξ) | Sigma-Delta (Ξ£-Ξ) | Delta-Sigma | Delta-Sigma |
| Integrated PGA | Yes | Yes | Yes | Yes |
| Pin-to-Pin Compatibility | Reference part | Yes - verified drop-in | Not verified pin-compatible | No - different pinout |
Key Differentiators
- Highest channel flexibility in the same footprint via AD7124-8 (vs AD7124-8BRUZ)
- Complete integrated analog front end reduces external BOM (vs MCP3564-E/ST)
- Package-grade consistency within the -4 ordering options (vs ADS124S08IPBS)
Design Notes
The AD7124-4 offers multiple power modes that trade current consumption against rms noise and maximum output data rate. For battery-powered designs, select the lowest power mode and duty-cycle conversions, using the DOUT/RDY ready indication to wake the host MCU only when data is available. For mains-powered precision instruments, a higher power mode reduces noise and enables faster channel scanning. Estimated: verify total analog supply current against your loop or battery budget in the chosen mode using the tables in the manufacturer datasheet before finalizing the power architecture.
Keep the analog input traces to AIN0-AIN5 short and symmetric, and place reference and supply decoupling capacitors directly at the AD7124-4 pins. Separate the analog ground from digital return paths of the SPI bus, joining them at a single point near the device. According to the Analog Devices EVAL-AD7124 evaluation board hardware guide, the reference layout routes sensitive analog signals away from SCLK/DIN/DOUT lines and provides dedicated decoupling for the analog supplies - mirror this topology in production PCBs for best noise performance.
Do not assume the TSSOP and LFCSP AD7124-4 variants are interchangeable: the datasheet explicitly states the B grade has package and performance differences between package options, so a footprint designed for AD7124-4BRUZ cannot simply accept the LFCSP part. Also remember that DOUT/RDY is a multifunction pin - per the datasheet, it is referred to by the full name or by a single function (e.g., RDY) as relevant - so firmware must handle the data-ready indication correctly during reads to avoid corrupted conversions.
Compliance Information
Compliance data was not present in the provided Verified Web Data; consult the Analog Devices product page for current RoHS/REACH status for AD7124-4BRUZ.
