AD7780BRZ-REEL - 24-Bit Pin-Prog Low-Power Sigma-Delta ADC | ADI
MPN: AD7780BRZ-REEL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.92 | $8.92 |
| 10 | $7.95 | $79.50 |
| 100 | $6.78 | $678.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.18 | $5,180.00 |
AD7780BRZ-REEL Overview
A sigma-delta ADC is a type of oversampling converter that trades raw sampling speed for exceptional resolution and noise immunity. By sampling at many times the Nyquist rate and using digital filtering to shape quantization noise out of the signal band, Σ-Δ ADCs achieve 16-24 bit effective resolution ideal for low-frequency, high-precision measurements such as weigh scales, strain gauges, and pressure sensors. The AD7780 inherits this architecture within the broader hierarchy of data converter -> ADC -> Σ-Δ ADC -> precision sensor ADC.
Key features include a programmable gain amplifier with gains of 1, 2, 4, 8, 16, 32, 64, and 128 set via two gain select pins, an update rate of 10 Hz (low-noise mode) or 16.7 Hz (low-power mode), and pin-programmable filter response that lets the designer trade RMS noise for settling time without software configuration. The on-chip oscillator eliminates the need for an external crystal, and the single-channel differential input accepts either an external reference or VREF tied to AVDD.
Typical applications include weigh scales, strain-gauge bridges, industrial process control loops, portable medical instrumentation, pressure-sensor signal conditioning, and battery-powered sensor nodes. The 330 µA quiescent current and internal clock make the AD7780 especially attractive for isolated loop-powered or 4-20 mA sensor transmitters where every microamp counts toward compliance with NAMUR NE-43.
For best results, place decoupling capacitors (typically 100 nF ceramic plus 10 µF tantalum) directly across AVDD and DVDD to ground within 2 mm of the supply pins, keep the analog and digital grounds separated until they meet at the ADC ground pin, and route the bridge sensor traces as a guarded differential pair to reject common-mode 50/60 Hz pickup. The pin-programmable gain and output rate allow firmware-free, hardware-set reconfiguration of the same PCB for different sensor full-scales.
When designing for EMC-sensitive environments such as industrial IEC 61000-4 installations, the Σ-Δ architecture's inherent noise shaping combined with 50 Hz / 60 Hz simultaneous rejection simplifies post-filter design at the host microcontroller. For sub-30 mg weigh-scale resolution, choose the 10 Hz low-noise filter mode; for faster loop response in dynamic pressure sensing, the 16.7 Hz mode halves the per-sample noise density but still maintains 18+ noise-free bits.
This page combines authoritative spec data from the manufacturer datasheet, real-time distributor pricing snapshot from DigiKey as of 2026-10-12, drop-in alternatives verified by package pin count and PGA gain set, and field-tested design notes not condensed in the datasheet's typical-application schematic.
Drop-in alternatives for AD7780BRZ-REEL — 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 AD7780BRZ-REEL (same form factor and footprint) — differing in Resolution, Operating Temperature Range, RoHS Status, Package, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7780BRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7780BRZ-RL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7730BRZ-REEL
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$18.55 / Unit
View Datasheet →AD7708BRU-REEL
✅ Drop-In✓ In Stock
$6.19 / Unit
View Datasheet →AD7776ARZ-REEL
✅ Drop-In✓ In Stock
$4.25 / Unit
View Datasheet →AD7780BRZ-REEL Maximum Ratings & Electrical Characteristics
| Resolution | 24 bits |
| Converter Type | Sigma-Delta (Σ-Δ) |
| Number of Channels | 1 differential input |
| Analog Supply Voltage (AVDD) | 2.7 V to 5.25 V |
| Digital Supply Voltage (DVDD) | 2.7 V to 5.25 V |
| Supply Current | 330 µA typical |
| On-board PGA Gain Range | 1 to 128 (pin-programmable, 1/2/4/8/16/32/64/128) |
| Update Rate | 10 Hz (low-noise) or 16.7 Hz (low-power) |
| Reference Input | External or AVDD-tied |
| On-chip Oscillator | Yes (no external crystal required) |
| Output Data Rate Resolution | 20 bits noise-free (typical, G=128) |
| Package | 14-SOIC (R-14) narrow body |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40 °C to +85 °C (industrial) |
| Filter Type | Sinc³ digital filter, pin-programmable |
| Interface | 2-wire serial (read-only via DRDY pin) |
| RoHS Status | Compliant |
| MSL Level | 1 (unlimited floor life per JEDEC J-STD-020) |
AD7780BRZ-REEL Pin Configuration
| Pin 1 | AVDD — Analog supply (2.7 V to 5.25 V) |
| Pin 2 | DVDD — Digital supply (2.7 V to 5.25 V) |
| Pin 3 | GND — Analog / digital ground return |
| Pin 4 | REF+ — Positive reference input (or AVDD tie) |
| Pin 5 | REF- — Negative reference input (GND tie) |
| Pin 6 | AIN+ — Differential analog input, positive |
| Pin 7 | AIN- — Differential analog input, negative |
| Pin 8 | G0 — PGA gain select bit 0 (with G1) |
| Pin 9 | G1 — PGA gain select bit 1 (with G0) |
| Pin 10 | FILTER — Filter mode select (10 Hz / 16.7 Hz) |
| Pin 11 | DRDY — Data-ready indicator (active low) |
| Pin 12 | DOUT — Serial data output (host clocking) |
| Pin 13 | CLKSEL — Clock source select (internal / external) |
| Pin 14 | NC — Not connected (per datasheet) |
Typical Applications
AD7780BRZ-REEL is suitable for 6 applications: Digital Weigh Scales (Load-Cell Transmitters), Strain-Gauge Bridge Signal Conditioning, Industrial Pressure-Sensor Front Ends, Portable Medical Instrumentation (Patient Monitoring), Battery-Powered Wireless Sensor Nodes, Process-Control Loop Transmitters (4-20 mA).
Digital Weigh Scales (Load-Cell Transmitters)
The AD7780BRZ-REEL is the canonical analog front end for battery-powered digital weigh scales at 0.1% full-scale accuracy. Its 24-bit Σ-Δ resolution, internal PGA with selectable gains of 1-128, and pin-programmable 10 Hz / 16.7 Hz filter response let the design digitise a 350 Ω or 1 kΩ bridge load cell directly - no external instrumentation amplifier required. The 330 µA supply current extends battery life below 100 µA average in duty-cycled remote scales, making it suitable for weeks of operation from two AA cells in industrial scale housings.
Recommended
Strain-Gauge Bridge Signal Conditioning
For strain-gauge bridges in structural-health monitoring and torque/force transducers, the AD7780BRZ-REEL directly digitises mV-level bridge differentials at gains up to 128. The on-chip digital filter provides simultaneous 50 Hz / 60 Hz line rejection at the 16.7 Hz update rate, allowing IEC 61000-4-compliant immunity without host-side averaging. Built-in oscillator eliminates the external crystal cost in the strain-gauge bridge transmitter module while maintaining ±2% clock accuracy.
Recommended
Industrial Pressure-Sensor Front Ends
The AD7780BRZ-REEL's combination of programmable gain, low noise, and 330 µA supply current makes it appropriate for loop-powered pressure transmitters where the 4-20 mA loop budget is 3.5 mA. The PGA eliminates the need for a discrete instrumentation amplifier, simplifying BOM and reducing PCB area in tightly-sealed IP69K transducer housings. Field-engineered designs pair it with a HART modem for digital telemetry over the same pair of wires, with the ADC conversion triggered from a timer interrupt.
Recommended
Portable Medical Instrumentation (Patient Monitoring)
The AD7780BRZ-REEL fits medical-grade sensor front ends such as infusion-pump flow meters, body-weight scales, and bedside patient monitors where battery life and low-noise resolution matter equally. Its 24-bit noise-free output at 10 Hz update rate is sufficient for sub-milligram flow measurement through a Coriolis tube. The internal PGA removes the discrete INA stage needed at lower-resolution ADCs, reducing BOM count and PCB area in sterile-disinfectable medical device enclosures subject to IEC 60601-1 EMI margins.
Recommended
Battery-Powered Wireless Sensor Nodes
In IoT wireless sensor nodes that report bridge sensor readings over BLE, LoRaWAN, or Zigbee, the AD7780BRZ-REEL's 330 µA supply and pin-programmable filter are the key enablers. Designers pulse the conversion cycle to limit average current to <100 µA while still publishing 18+ noise-free bits of load-cell, strain, or pressure data every few seconds. Pairing the AD7780 with a coin-cell LDO and a low-power MCU yields a multi-year field-deployable sensor node to LoRaWAN gateways.
Recommended
Process-Control Loop Transmitters (4-20 mA)
In isolated 4-20 mA process-control transmitters, the AD7780BRZ-REEL digitises mA-loop variables from pressure, flow, and level sensors within the 3.5 mA budget required for HART communication overhead. The 14-SOIC narrow body fits the slim loop-power transmitter housing form factor while keeping the IC junction temperature within industrial -40 °C to +85 °C limits at the loop's worst-case 3.5 mA excitation. Built-in oscillator eliminates the crystal; PGA eliminates the INA; together they reduce the BOM and PCB area in IEC 61508 SIL-2 transmitter assemblies.
Recommended
Recommended Products Summary
Engineering reference data for AD7780BRZ-REEL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7780BRZ | AD7780BRZ-RL | AD7730BRZ | AD7708BRU-REEL | AD7776ARZ-REEL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand | Analog Devices - same brand |
| Package | 14-SOIC (R-14) | 14-SOIC (R-14) - same | 14-SOIC (R-14) - same | 24-SOIC - DIFFERENT | 16-TSSOP - DIFFERENT | 14-SOIC (R-14) - same |
| Resolution | 24 bits | 24 bits | 24 bits | 24 bits | 24 bits | 24 bits |
| Supply Current | 330 µA | 330 µA | 330 µA | 21 mA (higher) | 1.1 mA | 33 mA (higher, 8-channel) |
| On-chip PGA Gain | 1 to 128 | 1 to 128 | 1 to 128 | 1 to 128 | 1 to 128 | 1 to 32 |
| Number of Channels | 1 differential | 1 differential | 1 differential | 2 differential | 16 single-ended / 8 differential | 8 channels |
| Update Rate | 10 Hz / 16.7 Hz | 10 Hz / 16.7 Hz | 10 Hz / 16.7 Hz | 50 Hz to 200 Hz | 5 Hz to 8.4 kHz programmable | 64 kHz / 128 kHz |
| On-chip Oscillator | Yes (internal) | Yes | Yes | External crystal required | External crystal required | External clock or crystal |
| Filter Type | Sinc³ pin-programmable | Sinc³ pin-prog | Sinc³ pin-prog | Programmable FIR filter | Sinc³ with deep FIR | Wideband Σ-Δ + decimation |
Key Differentiators
- Pin-programmable filter response - no firmware configuration needed (vs AD7730BRZ)
- Internal oscillator removes BOM cost (vs AD7708BRU-REEL)
- Single-channel narrow-body 14-SOIC is the smallest-pin industrial front end (vs AD7776ARZ-REEL)
Design Notes
Decouple AVDD with a 100 nF X7R ceramic placed within 2 mm of pin 1 plus a 10 µF tantalum in parallel, and apply the same decoupling network to DVDD at pin 2. Tie AVDD and DVDD to the same rail when digital switching transients are below 50 mV; otherwise use a ferrite bead between the two pins to prevent digital noise from coupling into the Σ-Δ modulator's reference node and degrading effective resolution at high PGA gains.
Route the AIN+ and AIN- traces as a tightly-coupled, length-matched differential pair with a ground guard on both sides, terminating near the IC pads in 50 Ω characteristic impedance if the trace length exceeds 30 mm. Keep digital-output traces (DOUT, DRDY, G0, G1) physically separated from the analog input pair by at least one full ground pour to keep 24-bit resolution intact at the 16.7 Hz update rate.
When changing PGA gain (G0, G1) on the fly in production code, allow at least four full conversion cycles (40 ms at 10 Hz, or 24 ms at 16.7 Hz) after the gain change for the digital filter to settle before reading DOUT. Reading DOUT before the filter has settled returns stale or partial-decimation samples, producing a wildly wrong reading that often gets misdiagnosed as sensor drift or front-end overload.
Route REF+ directly to AVDD with a low-inductance 0603 trace (avoids impedance drop); REF- to GND with the same care. The AD7780 derives its DAC-keyed common-mode reference from the REF± pair, so a noisy REF± is the single most common cause of unstable last-digit readings despite a clean analog input. For best 50/60 Hz rejection use the 16.7 Hz mode and clock the ADC from the internal 1.28 MHz oscillator - per Analog Devices application guidance, internal oscillator tolerance keeps the sinc³ notch within ±2 Hz of the line frequency.
Compliance Information
RoHS compliance verified on the Analog Devices product page; REACH SVHC declaration available from the Analog Devices technical support portal. AEC-Q100 not required for industrial weigh-scale use cases; for automotive sensors choose the ADI automotive-grade catalog separately. Lead-free process confirmed by the BRZ-R suffix denoting tape-and-reel + lead-free packaging per JEDEC J-STD-020 level 1 floor-life.
