AD7730BRUZ - 24-Bit Sigma-Delta Bridge Transducer ADC | Analog Devices
MPN: AD7730BRUZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $19.66 | $19.66 |
| 10 | $17.69 | $176.90 |
| 100 | $15.73 | $1,573.00 |
| 500 | $14.25 | $7,125.00 |
| 1,000 | $13.1 | $13,100.00 |
AD7730BRUZ Overview
An analog front end (AFE) is the signal-conditioning stage that sits between a sensor and a digital processor. In bridge-sensor applications the AFE must amplify microvolt-level signals, reject 50 Hz/60 Hz line noise, and present a clean digital word to the MCU or DSP. The AD7730 combines a precision programmable-gain instrumentation front end, a 24-bit sigma-delta modulator, and a digital low-pass filter on a single die, eliminating the external IA and ADC pair that older weigh-scale designs required. Architecturally it belongs to the wider ADC family -> sigma-delta ADC -> 24-bit ADC -> precision data acquisition IC -> signal chain.
Key features include 5 nV/C offset drift, 2 ppm/C gain drift, greater than 150 dB line-frequency rejection, and four unipolar input ranges (0 to +/-10 mV, +20 mV, +40 mV, +80 mV) plus four bipolar ranges (+/-10 mV, +/-20 mV, +/-40 mV, +/-80 mV). Two buffered differential inputs and a differential reference input allow direct connection to a four-wire bridge. On-chip self-calibration and system-calibration routines remove offset and gain error after PCB assembly.
Typical applications include electronic weigh scales, load-cell transmitters, pressure transducers, and industrial process-control front ends. The TSSOP-24 footprint also makes it a fit for medical infusion pumps and force-measurement instrumentation where board area is constrained and a true 24-bit noise-free conversion is required.
When designing with the AD7730BRUZ, separate the analog AVDD and digital DVDD supplies and decouple each pin with 100 nF ceramic plus a 10 uF bulk capacitor. Use a low-noise reference such as the ADR03 / ADR420 and keep the bridge excitation current return path close to the analog ground plane.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for AD7730BRUZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD7730BRUZ (same form factor and footprint) — differing in Package, Resolution, Number of Channels, Operating Temperature, Supply Voltage.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7730BRUZ-REEL7
✅ Drop-In✓ In Stock
$17.4 / Unit
View Datasheet →AD7730LBRUZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7730BRUZ Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices |
| Part Number | AD7730BRUZ |
| Function | 24-bit sigma-delta analog front end for bridge transducers |
| Resolution | 24-bit (up to 230,000 counts peak-to-peak) |
| Number of Channels | 1 differential (2 buffered inputs) |
| Supply Voltage | +4.75 V to +5.25 V (single +5 V) |
| Typical Power Dissipation | 125 mW |
| Analog Input Ranges (Unipolar) | 0 to +10 mV, 0 to +20 mV, 0 to +40 mV, 0 to +80 mV |
| Analog Input Ranges (Bipolar) | +/-10 mV, +/-20 mV, +/-40 mV, +/-80 mV |
| Offset Drift | 5 nV/C (max) |
| Gain Drift | 2 ppm/C (max) |
| Line-Frequency Rejection | >150 dB |
| Reference Input | Differential |
| Digital Interface | Serial, compatible with microcontrollers and DSPs (3-wire mode) |
| Calibration | On-chip self-calibration and system calibration |
| Package | 24-lead TSSOP (RU-24) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| AEC-Q100 | Not qualified (industrial grade only) |
AD7730BRUZ Pin Configuration
| Pin 1 | SCLK — Serial clock input |
| Pin 2 | DOUT — Serial data output |
| Pin 3 | DIN — Serial data input |
| Pin 4 | CS — Chip select, active low |
| Pin 5 | RESET — Reset input, active low |
| Pin 6 | MODE — Mode select for filter/notch |
| Pin 7 | A0 — Register address select |
| Pin 8 | STANDBY — Standby input, active high |
| Pin 9 | SYNC/~RDY — Synchronization / ready output |
| Pin 10 | DGND — Digital ground |
| Pin 11 | DVDD — Digital +5 V supply |
| Pin 12 | AVDD — Analog +5 V supply |
| Pin 13 | REF IN+ — Differential reference input positive |
| Pin 14 | REF IN- — Differential reference input negative |
| Pin 15 | AGND — Analog ground |
| Pin 16 | AIN1+ — Analog input 1 positive |
| Pin 17 | AIN1- — Analog input 1 negative |
| Pin 18 | AIN2+ — Analog input 2 positive |
| Pin 19 | AIN2- — Analog input 2 negative |
| Pin 20 | ACAL — Calibration capacitor |
| Pin 21 | ACAP — Analog filter capacitor |
| Pin 22 | ACOM — Analog common |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
Typical Applications
AD7730BRUZ is suitable for 6 applications: Electronic Weigh Scale / Load Cell, Pressure Transmitter / Process Control, Force Measurement and Load Monitoring, Medical Infusion Pump / Dosing System, Industrial Process Control Analog Input Module, Battery-Powered Weigh Indicator.
Electronic Weigh Scale / Load Cell
The AD7730BRUZ is the canonical bridge-AFE for single-channel bench and floor scales. Its 5 nV/C offset drift and 2 ppm/C gain drift hold calibration over the -40 C to +85 C industrial range, while >150 dB line-frequency rejection removes 50 Hz/60 Hz mains pickup. Placed between a 350 ohm 2 mV/V load cell and a microcontroller, with the bridge excitation shared with the reference input, it produces a noise-free 16-bit reading at the 10 mV range and is calibrated on power-up by the on-chip self-calibration routine. Compared with discrete INA + 24-bit ADC solutions, the integrated AFE drops 4-6 components and the calibration routine eliminates the manual trimpot.
Recommended
Pressure Transmitter / Process Control
Industrial pressure transmitters using strain-gauge or piezoresistive bridges benefit from the AD7730BRUZ's bipolar +/-10 mV to +/-80 mV input ranges and differential reference input. The bipolar ranges accommodate ratiometric measurements where the bridge output swings around the excitation voltage. Power dissipation of 125 mW is acceptable inside a loop-powered 4-20 mA transmitter head with proper thermal layout. The on-chip system-calibration routine lets the host MCU run a one-touch field calibration against a dead-weight tester, while 2 ppm/C gain drift keeps the 0.1 percent FS accuracy budget intact across process temperature swings.
Recommended
Force Measurement and Load Monitoring
Force plates, force-test rigs, and machine-tool load-monitoring systems need sub-microvolt resolution at low update rates, which is exactly the AD7730BRUZ's niche. The TSSOP-24 footprint drops onto the same PCB as a strain-gauge instrumentation amp frontend, eliminating a separate IA stage. Combined with chop mode and the digital filter's deep first notch, the part provides >20 bits of effective resolution in a 50 Hz or 60 Hz environment. Engineers should reserve 10 mm of board edge around the bridge traces and route the analog AVDD separately from the digital DVDD to preserve 5 nV/C offset drift.
Recommended
Medical Infusion Pump / Dosing System
Medical infusion pumps measure small differential pressures across a disposable flow element, and the AD7730BRUZ's 24-bit resolution with low input ranges is well matched to single-channel pressure sensing. The on-chip calibration supports periodic in-situ re-zeroing during the pump's self-test cycle, and the -40 C to +85 C industrial range covers the thermal envelope of an infusion-pump enclosure. Note that the AD7730BRUZ is NOT AEC-Q100 qualified and is not aimed at life-support devices, so it suits the dosing subsystem rather than the patient-isolation barrier.
Recommended
Industrial Process Control Analog Input Module
Process-control analog input modules that interface to load cells, weight feeders, and tank-weighing systems use the AD7730BRUZ as a single-channel 24-bit front end. Its serial interface is directly compatible with industrial microcontrollers and DSPs, and the TSSOP-24 footprint fits a standard 4 mm x 4 mm analog-frontend island. Differential reference input rejects ground-loop noise common in plant environments, and the on-chip digital filter's programmable first-notch frequency lets the same module serve 50 Hz and 60 Hz regions without firmware changes.
Recommended
Battery-Powered Weigh Indicator
Portable battery-powered weigh indicators for parcel scales, fishing scales, and handheld force gauges use the AD7730LBRUZ (the lower-power sibling of the AD7730BRUZ) at the heart of the analog section. The standard AD7730BRUZ with 125 mW dissipation is used where line power is available, while the AD7730L variant enables multi-month battery life. The same TSSOP-24 footprint and pinout let designers drop either die on the same PCB and select the variant at procurement, preserving one design across two power budgets.
Recommended
Recommended Products Summary
Engineering reference data for AD7730BRUZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7730BRUZ-REEL7 | AD7730LBRUZ |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Package | TSSOP-24 | TSSOP-24 | TSSOP-24 |
| Resolution | 24-bit, 230k counts p-p | 24-bit, 230k counts p-p | 24-bit, lower throughput |
| Input Ranges | +/-10 to +/-80 mV, 0 to +80 mV | +/-10 to +/-80 mV, 0 to +80 mV | +/-10 to +/-80 mV, 0 to +80 mV |
| Offset Drift | 5 nV/C | 5 nV/C | 5 nV/C |
| Gain Drift | 2 ppm/C | 2 ppm/C | 2 ppm/C |
| Line Rejection | >150 dB | >150 dB | >150 dB |
| Supply Voltage | +4.75 V to +5.25 V | +4.75 V to +5.25 V | +4.75 V to +5.25 V |
| Power Dissipation | 125 mW | 125 mW | Lower (AD7730L variant) |
Key Differentiators
- Only TSSOP-24 member of AD7730 family with full +125 mW throughput grade (vs AD7730LBRUZ)
- Industrial -40 C to +85 C specification (vs AD7730CBRUZ)
- Same-brand pin-compatible lower-power alternative exists in same package (vs AD7730LBRUZ)
Design Notes
Decouple AVDD and DVDD separately. Each analog pin gets a 100 nF ceramic capacitor placed within 5 mm of the pin plus a shared 10 uF bulk capacitor. Use a low-noise LDO such as the ADP150 to derive AVDD from a clean +5 V rail, and isolate the digital DVDD with a ferrite bead to keep digital switching noise out of the analog modulator.
Route the differential bridge traces (AIN1+, AIN1-, AIN2+, AIN2-, REF IN+, REF IN-) as a tightly coupled pair with 0.15 mm spacing and a continuous ground plane underneath. Guard the bridge traces with grounded copper on both sides of the differential pair, and avoid running digital traces (SCLK, DOUT, DIN) parallel to the analog traces to preserve the 5 nV/C offset drift budget.
Do not bypass the on-chip calibration routine. Run self-calibration at power-up and after every gain change, and run system-calibration once with the bridge installed to remove the system's zero-weight offset. Connecting ACAL and ACAP with the wrong capacitor value (datasheet recommends 0.1 uF) will cause the calibration to fail and the part will appear stuck at full-scale output.
Keep the bridge excitation current return path close to the analog ground plane. Use a Kelvin connection to the load cell so the voltage-sensing taps do not carry the bridge excitation current, which would otherwise introduce 2-5 ppm/C gain drift beyond the part's own 2 ppm/C specification.
Compliance Information
Per Analog Devices product page, AD7730BRUZ is RoHS compliant and lead-free. Not AEC-Q100 qualified; choose AEC-Q100 parts for automotive. Halogen-free status not stated on the verified product page.
