Part A
AD7730BRUZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7421 PCS
- Package
- TSSOP-24
- Series
- Data Acquisition - Analog Front End (AFE)
Replacement verdict
Compatible functional replacement candidate
The AD7731BRU is a functional replacement candidate for the AD7730BRUZ in many precision weigh-scale and low-frequency measurement designs, since both are pin-compatible 24-pin TSSOP sigma-delta ADCs with comparable resolution and supply requirements. However, the AD7730BRUZ integrates a dedicated bridge-excitation and AC-excitation feature set for load-cell applications, whereas the AD7731BRU is a general-purpose signal-conditioning ADC. Designers should validate the loss of bridge-specific excitation and the differences in output data rate and interface timing before substituting in bridge-sensor circuits.
Package Type
Validation required
Resolution
Validation required
Bridge Excitation Feature
Not compatible
Output Data Rate
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7730BRUZ | AD7731BRU | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit sigma-delta ADCs, so resolution alone does not distinguish them for substitutability. |
| Number of input channels | 2 differential | 3 differential | Channel count affects how many sensors or signal paths can be connected without external multiplexing. |
| Interface type | Serial (SPI-compatible) | Serial (SPI-compatible) | Both use a similar serial interface, easing firmware reuse when swapping parts. |
| Package / mounting | 24-TSSOP | 24-TSSOP | Identical package and footprint allow drop-in board replacement without layout changes. |
| Supply voltage (analog) | 5 V | 5 V | Matching analog supply requirements means the same power rail can be reused. |
| Input type / signal conditioning | Bridge/load-cell optimized with on-chip PGA | General-purpose with on-chip PGA | The AD7730 is tailored for weigh-scale bridge sensors, while the AD7731 is more general-purpose, affecting application fit. |
| Output data rate (max) | Up to 1.2 kSPS (programmable) | Up to 6.4 kSPS (programmable) | Higher output rate on the AD7731 supports faster sampling, which may matter for dynamic measurements. |
| On-chip features | Bridge excitation, burnout detection, AC excitation | PGA, calibration, burnout detection | Feature differences determine whether external circuitry is needed for a given sensor type. |
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 | AD7730BRUZ | AD7731BRU |
|---|---|---|
| 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 differences between the AD7730BRUZ and the AD7731BRU?
The AD7730BRUZ is a 24-bit sigma-delta load-cell ADC with on-chip PGA and AC excitation, while the AD7731BRU is a 24-bit sigma-delta ADC with a programmable gain front end but without the dedicated bridge/load-cell AC excitation circuitry. Both are supplied in 24-lead TSSOP packages, but they differ in their input signal conditioning and target applications.
Are the AD7730BRUZ and AD7731BRU pin-compatible?
Both devices are offered in a 24-lead TSSOP (RU) package, but pin functions are not identical. The AD7730BRUZ includes dedicated AC excitation and bridge-related pins, so a direct drop-in replacement should not be assumed. Pin assignments must be verified against the respective manufacturer datasheets before substitution.
What is the resolution and architecture of these two ADCs?
Both the AD7730BRUZ and AD7731BRU are 24-bit sigma-delta (ΔΣ) analog-to-digital converters. The AD7730BRUZ is optimized for weigh-scale and load-cell applications, while the AD7731BRU is a general-purpose high-resolution sigma-delta ADC with programmable gain.
Do both parts include a programmable gain amplifier (PGA)?
Yes. Both the AD7730BRUZ and AD7731BRU integrate a programmable gain front end, allowing direct connection of low-level sensor signals. The gain settings and input ranges should be confirmed from the respective datasheets for the specific design.
Which part is better suited for weigh-scale or load-cell designs?
The AD7730BRUZ is specifically designed for weigh-scale and load-cell applications, featuring AC excitation and bridge-related signal conditioning. The AD7731BRU is a general-purpose high-resolution ADC and lacks the dedicated load-cell excitation circuitry, so the AD7730BRUZ is the more application-specific choice for bridge sensor designs.
What package do the AD7730BRUZ and AD7731BRU use?
Both devices are available in a 24-lead TSSOP package, indicated by the "RU" suffix in their part numbers. PCB land patterns and thermal considerations should be verified against the manufacturer datasheets.
Can the AD7731BRU be used as a substitute for the AD7730BRUZ?
Substitution is not straightforward. Because the AD7730BRUZ includes dedicated AC excitation and bridge signal-conditioning features that the AD7731BRU does not, a replacement requires validating input configuration, excitation requirements, and pin functions against both datasheets before use in a target design.