Features and Benefits
- Up to 23 effective bits
- RMS noise: 40 nV @ 4.17 Hz, 85 nV @ 16.7 Hz
- Current: 400 μA typical
- Power-down: 1 μA maximum
- Low noise, programmable gain, instrumentation amp
- Band gap reference with 4 ppm/°C drift typical
- Update rate: 4.17 Hz to 470 Hz
- Six differential analog inputs
- Internal clock oscillator
- Simultaneous 50 Hz/60 Hz rejection
- Reference detect
- Programmable current sources
The AD7794/AD7795 are low power, low noise, complete analog front ends for high precision measurement applications. They contain a low noise, 24-/16-bit Σ-Δ ADC with six differential inputs. The on-chip low noise instrumentation amplifier means that signals of small amplitude can be interfaced directly to the ADC.
Each device contains a precision, low noise, low drift internal band gap reference, and can also accept up to two external differential references. Other on-chip features include programmable excitation current sources, burnout currents, and a bias voltage generator that is used to set the common-mode voltage of a channel to AVDD/2. The low-side power switch can be used to power down bridge sensors between conversions, minimizing the system’s power consumption. The AD7794/AD7795 can operate with either an internal clock or an external clock. The output data rate from each part can vary from 4.17 Hz to 470 Hz.
Both parts operate with a power supply from 2.7 V to 5.25 V. The B-grade parts (AD7794 and AD7795) are specified for a temperature range of −40°C to +105°C while the C-grade part (AD7794) is specified for a temperature range of −40°C to +125°C. They consume a current of 400 μA typical and are housed in a 24-lead TSSOP.
- Temperature measurement
- Pressure measurement
- Weigh scales
- Strain gage transducers
- Gas analysis
Markets and Technologies
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
The EVAL-AD7794EBZ is a fully featured evaluation Board for the AD7794. The evaluation board can be connected to a PC via a standard USB interface. Software is provided enabling the user to perform detailed analysis of the ADC's performance.
Please note: This Evaluation software does not run on Windows 8 or Windows 10 (USB driver is non-compliant with OS >Windows 7).
Application Notes (13)
Tools & Simulations
An interactive illustration showing the behavior of an idealized sigma-delta A/D converter.
AD7794 Companion Parts
Recommended Digital Isolators
- For cost sensitive designs: ADUM7440, ADUM7441, ADUM7442.
- For digital isolators with integrated isolated power: ADUM5401, ADUM5402, ADUM5403.
- For isolated USB designs in healthcare and industrial control: ADUM4160.
- For process control applications: ADUM1400, ADUM1200.
Recommended High Accuracy, Precision References - 2.5V
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.