My Inquiry
My Account
Analog Devices Inc. AD7794CRUZ
- Part No.:
- AD7794CRUZ
- Manufacturer:
- Analog Devices Inc.
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 24-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
AD7794CRUZ.pdf
- Description:
- IC ADC 24BIT SIGMA-DELTA 24TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:412
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AD7794CRUZ from Analog Devices is a 24-bit, low-noise, low-power Σ-Δ analog-to-digital converter with integrated instrumentation amplifier, on-chip band gap reference (4 ppm/°C drift), six differential inputs, and programmable excitation current sources. It delivers 23 effective bits at 4.17 Hz, 40 nV RMS noise, and operates from 2.7 V to 5.25 V - optimized for high-precision industrial sensor signal conditioning in weigh scales and pressure transducers.
For engineers reviewing the AD7794CRUZ datasheet, AD7794CRUZ pinout, AD7794CRUZ application, or AD7794CRUZ equivalent, key selection considerations include its guaranteed 24-bit no-missing-codes performance at ≤242 Hz update rate, simultaneous 50/60 Hz rejection, internal clock oscillator, and C-grade temperature range (–40°C to +125°C) for harsh-environment deployment.
Technical Context
The AD7794CRUZ implements a chopper-stabilized Σ-Δ modulator with digital filtering supporting output rates from 4.17 Hz to 470 Hz. Its on-chip instrumentation amplifier provides programmable gain (1–128) and supports buffered/unbuffered input modes with defined common-mode voltage constraints (e.g., GND + 300 mV to AVDD − 1.1 V for gain ≥4).
It integrates dual programmable current sources (10/210/1000 μA, ±5% initial tolerance), a bias voltage generator (AVDD/2), reference detect circuitry, and a low-side power switch (RON ≤9 Ω at 3 V) for bridge sensor power gating - all controlled via a 3-wire SPI-compatible serial interface with Schmitt-triggered SCLK.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 24-bit no-missing-codes (≤242 Hz, chop enabled); enables 1 ppm-level measurement fidelity in strain gage or RTD systems. |
| RMS Noise | 40 nV @ 4.17 Hz - allows sub-μV signal resolution without external amplification in precision weigh scale front ends. |
| Supply Current | 400 μA typical (internal reference, gain ≥4) - supports battery-powered portable instrumentation with >1-year runtime on coin cell. |
| Reference Drift | 4 ppm/°C typical (band gap) - eliminates need for external ovenized reference in industrial process controllers operating across –40°C to +125°C. |
| Update Rate | 4.17 Hz to 470 Hz programmable - permits trade-off between noise floor (low rate) and response time (high rate) in closed-loop control feedback paths. |
| Common-Mode Rejection | 100 dB min @ DC (B-grade), 97 dB min @ DC (C-grade) - rejects ground loop interference in 4–20 mA transmitter analog input stages. |
| INL Error | ±15 ppm of FSR - ensures linearity compliance for 6½-digit DVM and calibration-grade measurement equipment. |
Pinout & Package
AD7794CRUZ is housed in a 24-lead TSSOP (RU-24) package with exposed pad for thermal enhancement. Pin 4 is NC; pins 5/6 (AIN6(+)/P1 and AIN6(−)/P2) support dual-role analog input or general-purpose digital I/O; pins 15/16 (AIN5(+)/IOUT2 and AIN5(−)/IOUT1) serve as configurable excitation current outputs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SCLK (1) | Serial clock input | Schmitt-triggered for noise immunity; enables opto-isolated interface in high-noise industrial PLCs. |
| CS (3) | Chip select | Active-low frame sync; supports daisy-chain or multi-drop SPI bus with shared SCLK/DIN/DOUT lines. |
| AIN1(+) to AIN3(−) (7–12) | Differential analog inputs | Three dedicated 6-input channel pairs; support direct connection of Wheatstone bridges without external op amps. |
| REFIN1(±) (13–14) | Primary reference input | Accepts 0.1 V to AVDD differential reference; enables ratiometric measurements using same supply as sensor excitation. |
| PSW (19) | Low-side power switch | Drives bridge sensors; reduces system power by >99% between conversions in battery-operated gas analyzers. |
| DOUT/RDY (23) | Data output / ready indicator | Open-drain RDY asserts when conversion completes; simplifies timing in microcontroller-based data loggers. |
Key Features
| Feature | Design Value |
|---|---|
| Simultaneous 50 Hz/60 Hz rejection | 80 dB min rejection at both frequencies with single configuration (FS[3:0] = 1010), eliminating need for external notch filters in AC mains–coupled environments. |
| Programmable excitation currents | 10/210/1000 μA outputs with ±0.5% matching between IOUT1/IOUT2 - enables precise 2-/3-/4-wire RTD biasing without external DACs. |
| Burnout current sources | Internal 1 μA burnout currents on all analog inputs - provides open-circuit fault detection in smart transmitter diagnostics. |
| On-chip bias voltage generator | AVDD/2 output with fast start-up (ms/nF) - sets common-mode level for differential sensors, reducing PCB area vs. discrete resistor dividers. |
| Independent interface supply | DVDD pin accepts 2.7 V–5.25 V separate from AVDD - allows logic-level translation between 1.8 V MCU and 5 V analog domain without level shifters. |
Applications
| Temperature Measurement | Pressure Measurement |
|---|---|
Use Scenario: High-accuracy RTD or thermocouple readout in HVAC control panels with ambient temperature ranging from –40°C to +125°C. IC Role / Device Role / Timing Role: ADC front end with integrated PGA, reference, and excitation current sources - digitizes microvolt-level thermocouple EMF or ohmic RTD changes. Use Value: Eliminates external reference and current source ICs; 23 effective bits resolve <0.01°C increments in Class A Pt100 systems. |
Use Scenario: Industrial pressure transmitter with piezoresistive bridge sensor requiring ratiometric measurement and 4–20 mA loop power budgeting. IC Role / Device Role / Timing Role: Signal conditioner with low-side PSW and programmable gain - powers bridge only during conversion to minimize self-heating error. Use Value: 40 nV RMS noise at 4.17 Hz enables <0.05% FS repeatability; internal 4 ppm/°C reference avoids drift-induced zero-shift over temperature. |
| Weigh Scales | Strain Gage Transducers |
Use Scenario: Legal-for-trade platform scale with 10,000-count resolution and EMI immunity in factory-floor environments. IC Role / Device Role / Timing Role: Primary ADC with simultaneous 50/60 Hz rejection and burnout current diagnostics - interfaces directly to load cell full-bridge output. Use Value: 65 dB normal-mode rejection at 50 Hz suppresses lighting ballast interference; no-missing-codes guarantee ensures metrology compliance. |
Use Scenario: Structural health monitoring node measuring microstrain in civil infrastructure using bonded foil gages. IC Role / Device Role / Timing Role: Low-power Σ-Δ converter with 1 μA power-down mode - enables solar/battery operation with multi-year duty cycling. Use Value: 400 μA active current and 1 μA shutdown allow >5-year battery life in wireless sensor nodes sampling at 10 Hz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-precision sigma-delta ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7173-8BRUZ | 32-bit resolution, 250 kSPS max, external reference required, no on-chip PGA or excitation sources | Targeted at high-speed DAQ systems; lacks integrated sensor excitation and bias generation | Select when higher throughput (>1 kSPS) and external precision reference already exist; not drop-in for bridge/RTD front ends. |
| ADS124S08IPWR | 24-bit, 4-kSPS max, integrated PGA (1–128), two matched 10/200/1000 μA current sources, but no internal reference | Optimized for low-cost sensor nodes; requires external 2.5 V reference and has lower CMRR (95 dB typ) | Prefer for cost-sensitive designs where external reference is acceptable and 125°C operation is not required. |
Compared with AD7794CRUZ, AD7173-8BRUZ offers higher speed but demands external signal conditioning and reference, while ADS124S08IPWR reduces BOM count versus discrete solutions yet lacks the guaranteed C-grade temperature performance and internal 4 ppm/°C reference critical for uncooled industrial deployments.
Availability
AD7794CRUZ is available at Aetrix Electronics and suitable for weigh scales, pressure transmitters, and industrial process controllers requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for AD7794CRUZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design centers worldwide.
The AD7794 forms part of Analog Devices' precision Σ-Δ ADC product line, engineered specifically for high-resolution, low-power sensor signal acquisition in industrial, instrumentation, and medical measurement systems.
FAQ
What is the maximum operating temperature specification for AD7794CRUZ?
The AD7794CRUZ is rated for operation from –40°C to +125°C (C grade), making it suitable for under-hood automotive sensors, downhole oilfield tools, and industrial control cabinets without forced cooling. This exceeds the –40°C to +105°C range of the B-grade AD7794BRUZ, and is confirmed in the Rev. D datasheet Absolute Maximum Ratings table.
Does AD7794CRUZ require an external crystal or oscillator?
No, AD7794CRUZ includes an internal 64 kHz clock oscillator and can operate autonomously without external timing components. An external 64 kHz (or 128 kHz with divide-by-2) clock may be used for synchronization across multiple ADCs, but is optional - confirmed in the General Description and Timing Characteristics sections of the datasheet.
Can AD7794CRUZ drive a 4-wire RTD directly?
Yes, AD7794CRUZ supports 4-wire RTD measurement using its dual programmable excitation current sources (IOUT1/IOUT2) on pins 15/16 and internal Kelvin sensing via AIN1–AIN3 differential inputs. The ±0.5% current matching and low drift (200 ppm/°C) ensure accurate resistance calculation without external current DACs - detailed in the Excitation Current Sources specification table.
What is the purpose of the PSW pin on AD7794CRUZ?
The PSW (pin 19) is a low-side power switch with RON ≤9 Ω at 3 V, designed to gate power to bridge sensors (e.g., load cells, pressure bridges) between conversions. This minimizes self-heating and system power consumption - especially valuable in battery-powered AD7794CRUZ implementations like portable gas analyzers or field instruments.
How many differential input channels does AD7794CRUZ support?
AD7794CRUZ supports six fully differential analog input channels (AIN1 through AIN6), each with independent programmable gain and buffer configuration. These are implemented as three dedicated differential pairs (AIN1±, AIN2±, AIN3±) plus AIN4±, AIN5±, and AIN6± - explicitly shown in the Functional Block Diagram and Pin Configuration diagram of the AD7794/AD7795 Rev. D datasheet.
AD7794CRUZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 24-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Number of Bits:
- 24
- Sampling Rate (Per Second):
- 470
- Number of Inputs:
- 6
- Input Type:
- Differential
- Data Interface:
- SPI, DSP
- Configuration:
- MUX-ADC
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- 1
- Architecture:
- Sigma-Delta
- Reference Type:
- External, Internal
- Voltage - Supply, Analog:
- 2.7V ~ 5.25V
- Voltage - Supply, Digital:
- 2.7V ~ 5.25V
- Features:
- PGA, Temperature Sensor
- Operating Temperature:
- -40°C ~ 125°C
- Supplier Device Package:
- 24-TSSOP
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
AD7794CRUZ FAQ
1.How can I place an order for AD7794CRUZ through Aetrix?
Please submit a Request for Quotation (RFQ) for AD7794CRUZ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AD7794CRUZ reliable?
The price and inventory of AD7794CRUZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD7794CRUZ is usually 5 days.
3.What payment methods are accepted for AD7794CRUZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD7794CRUZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD7794CRUZ?
AD7794CRUZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD7794CRUZ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AD7794CRUZ?
For technical support, including AD7794CRUZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD7794CRUZ requirements.
6.How does Aetrix verify that AD7794CRUZ is sourced from the original manufacturer or authorized distributors?
All AD7794CRUZ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AD7794CRUZ meets industry standards.
7.What is the process for return or replacement of AD7794CRUZ?
All AD7794CRUZ units undergo pre-shipment inspection (PSI). If there is an issue with AD7794CRUZ, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AD7794CRUZ part is unused and in its original packaging.
Return procedure for AD7794CRUZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AD7794CRUZ Tags
-
ADC081C021CIMKX/NOPB
Texas Instruments
-
MCP3021A5T-E/OT
Microchip Technology
-
TLA2024IRUGR
Texas Instruments
-
MCP3221A5T-E/OT
Microchip Technology
-
MCP3221A5T-I/OT
Microchip Technology
-
MCP3221A4T-E/OT
Microchip Technology
-
MCP3221A6T-E/OT
Microchip Technology
-
MCP3221A0T-E/OT
Microchip Technology
-
MCP3221A1T-E/OT
Microchip Technology
-
ADC121S021CIMFX/NOPB
Texas Instruments
-
MCP3001-I/MS
Microchip Technology
-
MCP3001-I/SN
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
