Part A
AD7739BRUZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1798 PCS
- Package
- TSSOP-24
- Series
- Data Acquisition - Analog to Digital Converters (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
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.