Part A
AD7739BRUZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1798 PCS
- Package
- TSSOP-24
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Not a drop-in replacement
The AD7739BRUZ and AD7730BRU are both high-resolution sigma-delta load-cell ADCs from Analog Devices, but they differ in resolution, output data rate, interface timing, and package footprint. The AD7739BRUZ offers 24-bit resolution with faster throughput, while the AD7730BRU provides 16-bit to 24-bit selectable resolution with a different digital interface and TSSOP-24 package. Because these differences affect system accuracy, timing, and board layout, the AD7739BRUZ is not a direct drop-in replacement for the AD7730BRU and requires design validation before substitution.
Different resolution
Different output data rate
Different digital interface
Different package footprint
Parts at a glance
Part B
AD7730BRU
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 2068 PCS
- Package
- TSSOP-24
- Series
- Acquisition de données - Analog Front End (AFE)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7739BRUZ | AD7730BRU | 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 | 8 (differential) | 2 (differential) | Channel count determines how many sensors or signals can be multiplexed into a single device; the AD7739 supports far more inputs. |
| Maximum sample rate | 15.1 kSPS | 1.2 kSPS | Higher throughput enables faster data acquisition and wider signal bandwidth; the AD7739 is significantly faster. |
| Interface type | SPI / QSPI / MICROWIRE / DSP-compatible serial | SPI-compatible serial | Interface compatibility affects whether the part can drop into an existing digital bus without firmware or hardware changes. |
| Analog supply voltage | 5 V | 5 V | Matching analog supply rails simplifies power design and ensures comparable input range behavior. |
| Digital supply voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Flexible digital supply allows direct interfacing to both 3 V and 5 V logic; identical here. |
| Package | 24-lead TSSOP | 24-lead TSSOP | Same package footprint allows potential board-level interchangeability without layout changes. |
| Operating temperature range | -40 °C to +105 °C | -40 °C to +85 °C | Wider temperature range in the AD7739 suits harsher industrial environments. |
| Integrated PGA / gain stages | Yes (programmable gain) | Yes (programmable gain) | On-chip programmable gain allows direct connection of low-level sensors without external amplification. |
| Typical application focus | Multichannel industrial measurement / process control | Weigh scales / bridge transducer applications | Different intended applications mean the parts are not drop-in substitutes despite shared core ADC architecture. |
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 | AD7739BRUZ | AD7730BRU |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 24 | 24 |
| Number of Channels | - | 1 |
| Power (Watts) | - | 125 mW |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 2.7V ~ 5.25V |
| Mounting Type | - | Surface Mount |
| Sampling Rate(Per Second) | 15.1k | - |
| Number of Inputs | 4, 8 | - |
| Input Type | Differential, Single Ended | - |
| Data Interface | SPI, DSP | - |
| Configuration | MUX-ADC | - |
| Number of A/D Converters | 1 | - |
| Architecture | Sigma-Delta | - |
| Reference Type | External | - |
| Features | True Bipolar | - |
| Operating Temperature | -40°C ~ 105°C | - |
Frequently asked questions
What are the primary functional differences between the AD7739BRUZ and the AD7730BRU?
The AD7739BRUZ is a 24-bit, 8-channel, low-voltage, low-power sigma-delta ADC designed for high-resolution multiplexed signal acquisition, while the AD7730BRU is a 24-bit sigma-delta ADC optimized specifically for weigh-scale and pressure-sensor applications, featuring internal PGA, AC excitation, and a 2-channel differential input structure. The AD7739 offers more input channels and a different digital interface, whereas the AD7730 integrates dedicated bridge-excitation and burnout-detection functions for load-cell systems.
Are the AD7739BRUZ and AD7730BRU pin-compatible?
No. Both devices are supplied in a 24-lead TSSOP (RU suffix), but their pin functions and internal signal routing differ. The AD7739BRUZ provides eight single-ended or four differential input channels with a different digital I/O arrangement, while the AD7730BRU provides two differential analog inputs plus dedicated AC excitation and reference pins. A direct drop-in replacement is not supported without PCB and firmware redesign.
Do both parts support the same supply voltage range?
The AD7739BRUZ operates from a single 3.0 V to 5.25 V analog supply (AVDD) and a 2.7 V to 5.25 V digital supply (DVDD), supporting low-voltage system designs. The AD7730BRU operates from a 5 V analog supply and a separate 2.7 V to 5.25 V digital supply. Designs migrating between the two must verify that the analog supply rail meets the respective device requirements.
Which device is better suited for multi-channel data acquisition systems?
The AD7739BRUZ is better suited for multi-channel data acquisition because it provides eight single-ended or four fully differential input channels with an on-chip multiplexer, allowing multiple sensors to be scanned by a single converter. The AD7730BRU is limited to two differential input channels and is intended for single-bridge or dual-bridge weigh-scale configurations rather than general-purpose multiplexed acquisition.
Does the AD7730BRU include features not present in the AD7739BRUZ for weigh-scale applications?
Yes. The AD7730BRU integrates a programmable gain amplifier, AC excitation outputs for ratiometric bridge measurement, and burnout current sources for sensor fault detection, which are specifically tailored to load-cell and strain-gauge systems. The AD7739BRUZ does not include dedicated AC bridge-excitation circuitry, so weigh-scale designs requiring those functions should use the AD7730BRU.
What are the resolution and output data rate characteristics of each device?
Both devices are 24-bit sigma-delta ADCs. The AD7739BRUZ provides programmable output update rates suitable for multiplexed low-frequency signal acquisition, while the AD7730BRU offers selectable output update rates optimized for weigh-scale filtering, including rejection of 50 Hz and 60 Hz line frequencies. Exact noise-free resolution depends on gain, filter setting, and output rate, and should be taken from the respective manufacturer datasheets.
Can the AD7739BRUZ directly replace the AD7730BRU in an existing weigh-scale design?
No. Although both are 24-bit sigma-delta converters in 24-lead TSSOP packages, the AD7739BRUZ lacks the AD7730BRU's integrated AC excitation outputs, burnout detection, and weigh-scale-specific digital filter configuration. Replacing the AD7730BRU with the AD7739BRUZ would require external bridge-excitation circuitry, revised firmware for register mapping and filter settings, and revalidation of the analog front end.
What digital interface does each device provide?
Both devices provide a serial interface for connection to a microcontroller or DSP. The AD7739BRUZ uses a SPI-compatible serial interface with separate data-ready and control signals supporting multiplexed channel reads. The AD7730BRU also provides a serial interface but includes dedicated registers and modes for weigh-scale calibration, AC excitation control, and burnout current control. Firmware developed for one device is not directly portable to the other without register-level modification.