Part A
AD7730BRZ
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 1585 PCS
- Package
- SOIC-24
- Series
- 데이터 수집 - 아날로그 프런트엔드(AFE)
Replacement verdict
Compatible functional replacement candidate
The AD7731BR-REEL is a functional replacement candidate for the AD7730BRZ, sharing the same 24-bit sigma-delta architecture, SPI-compatible serial interface, and 24-lead SOIC footprint, but it is not a drop-in replacement. The AD7731 offers a faster maximum output rate and lower noise, while the AD7730 provides a dedicated weigh-scale front end with AC excitation and higher gain settings. Designers must validate gain range, output data rate, and excitation requirements against the target application before substituting.
Resolution and Architecture
Validation required
Output Data Rate
Validation required
Package and Pinout
Validation required
Analog Front-End Features
Validation required
Parts at a glance
Part B
AD7731BR-REEL
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 6695 PCS
- Package
- SOIC-24
- Series
- 데이터 수집 - 아날로그 변환기(ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7730BRZ | AD7731BR-REEL | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit sigma-delta ADCs, so resolution alone does not differentiate them for substitutability. |
| Number of input channels | 2 differential | 3 differential / 5 pseudo-differential | Channel count determines how many signal sources can be connected; the AD7731 offers more inputs, affecting system architecture. |
| Maximum output data rate | 1.2 kSPS | 6.4 kSPS | Higher output data rate enables faster sampling and wider signal bandwidth, which is critical for dynamic measurements. |
| Interface type | Serial (SPI-compatible, 3-wire) | Serial (SPI-compatible, 3-wire) | Both use a similar serial interface, so microcontroller/FPGA connectivity is largely interchangeable. |
| Supply voltage (analog) | 5 V | 5 V | Matching analog supply simplifies power-rail design and ensures comparable input range behavior. |
| Package | 24-lead SOIC (wide body) | 24-lead SOIC (wide body) | Identical package footprint allows drop-in PCB replacement without layout changes. |
| On-chip PGA | Yes (gain 1 to 128) | Yes (gain 1 to 128) | An integrated PGA allows direct connection of low-level sensors without external amplification, preserving signal integrity. |
| Operating temperature range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both suit the same industrial environments. |
| Special feature | Optimized for weigh-scale/bridge sensors with AC excitation | General-purpose low-noise ADC with fast settling | The AD7730 includes bridge/load-cell-specific features (AC excitation), while the AD7731 targets general low-noise signal acquisition, affecting application fit. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7730BRZ | AD7731BR-REEL |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | - | 6.4k |
| Number of Inputs | - | 3, 5 |
| Input Type | - | Differential |
| Data Interface | - | SPI, DSP |
| Configuration | - | MUX-PGA-ADC |
| Number of A/D Converters | - | 1 |
| Architecture | - | Sigma-Delta |
| Reference Type | - | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | 5V |
| Features | - | PGA |
| Operating Temperature | - | -40°C ~ 85°C |
| Number of Channels | 1 | - |
| Power (Watts) | 125 mW | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the key architectural differences between the AD7730BRZ and AD7731BR-REEL?
The AD7730BRZ is a 24-bit sigma-delta load cell ADC with two differential input channels and on-chip programmable gain amplifiers (PGA) supporting gains from 1 to 128, designed primarily for weigh-scale and pressure-sensor applications. The AD7731BR-REEL is a 24-bit sigma-delta ADC with three differential input channels and a PGA supporting gains from 1 to 128, offering higher channel count and faster output rates up to 800 Hz. Both are manufactured by Analog Devices in a 24-lead SOIC package, but the AD7731 provides three input channels versus two on the AD7730.
Are the AD7730BRZ and AD7731BR-REEL pin-compatible?
No. Although both devices are housed in a 24-lead SOIC (RW-24) package, their pin functions differ. The AD7730BRZ includes dedicated load-cell-specific features such as AC excitation and a burnout current source on specific pins, while the AD7731BR-REEL assigns pins to a third differential input channel and different digital control signals. A direct drop-in replacement is not possible without PCB redesign and firmware changes.
What are the maximum output data rates for each device?
The AD7730BRZ supports programmable output update rates up to 200 Hz in its standard configuration, with selectable filter options for weigh-scale applications. The AD7731BR-REEL supports output data rates up to 800 Hz, making it better suited for higher-speed multi-channel signal acquisition. Designers should confirm the exact rate against the Analog Devices datasheet for the specific filter and gain settings used.
How do the input channel configurations compare?
The AD7730BRZ provides two differential analog input channels, optimized for bridge transducer and load-cell applications. The AD7731BR-REEL provides three differential analog input channels, allowing more sensor inputs per device. This difference affects system channel density and the number of ADCs required in a multi-sensor design.
Do both parts support the same supply voltage and interface?
Both devices operate from a single 5 V analog supply (AVDD) with a separate digital supply (DVDD) of 3 V to 5 V, and both provide a serial SPI-compatible interface for communication with a host microcontroller. However, register maps and control-word formats differ between the two devices, so firmware written for one cannot be reused unchanged on the other.
Which device is more appropriate for weigh-scale applications?
The AD7730BRZ is specifically designed for weigh-scale and load-cell applications, featuring AC excitation to reduce thermal EMF effects, a burnout current source for sensor fault detection, and a programmable filter optimized for low-noise bridge measurements. The AD7731BR-REEL is a more general-purpose multi-channel ADC and lacks the load-cell-specific AC excitation feature, so the AD7730BRZ is generally preferred for precision weighing designs.
What package and temperature grade do these devices share?
Both the AD7730BRZ and AD7731BR-REEL are offered in a 24-lead SOIC package and are specified for the industrial temperature range of −40°C to +85°C. The "BRZ" and "BR" suffixes indicate the industrial-grade SOIC package option from Analog Devices; designers should verify the exact ordering code and reel packaging against the manufacturer's ordering guide.