Overview
The AD7794BRUZ is a high-precision, low-power, 24-bit Sigma-Delta Analog-to-Digital Converter (ADC) manufactured by Analog Devices Inc. This component is designed for high-precision measurement applications and features a low noise, complete analog front end. It includes a low noise instrumentation amplifier, allowing signals of small amplitude to be directly interfaced to the ADC. The device is housed in a 24-lead Thin Shrink Small Outline Package (TSSOP) and operates within a temperature range of -40°C to +105°C for B-grade parts and up to +125°C for C-grade parts.
Key Specifications
| Parameter | Value | Unit | Comments |
|---|---|---|---|
| Number of Bits | 24 | ||
| Sampling Rate | 4.17 Hz to 470 Hz | Hz | |
| Polarity | Bipolar | ||
| Interface | SPI, QSPI, MICROWIRE, DSP compatible | 3-wire serial interface | |
| Number of A/D Converters | 1 | ||
| Min Supply Voltage | 2.7 V | V | |
| Max Supply Voltage | 5.25 V | V | |
| Temperature Range | -40°C to +105°C (B-grade), -40°C to +125°C (C-grade) | °C | |
| Package | 24-TSSOP (0.173", 4.40mm Width) | ||
| Current Consumption | 400 μA typical | μA | |
| Integral Nonlinearity | ±15 ppm of FSR max | ppm | |
| Offset Error | ±1 μV typ | μV | |
| Gain Drift vs. Temperature | ±1 ppm/°C typ (gain = 1 to 16), ±3 ppm/°C typ (gain = 32 to 128) | ppm/°C |
Key Features
- Low noise, 24-bit Sigma-Delta ADC with six differential inputs
- On-chip low noise instrumentation amplifier for direct interfacing of small amplitude signals
- Precision, low noise, low drift internal band gap reference with 4 ppm/°C drift typical
- Accepts up to two external differential references
- Programmable excitation current sources, burnout currents, and bias voltage generator
- Low-side power switch to power down bridge sensors between conversions, minimizing power consumption
- Operates with either an internal or external clock
- Simultaneous 50 Hz/60 Hz rejection and reference detect
- Independent interface power supply
- RMS noise: 40 nV at 4.17 Hz, 85 nV at 16.7 Hz
Applications
- Temperature measurement
- Pressure measurement
- Weigh scales
- Strain gage transducers
- Gas analysis
- Industrial process control
- Instrumentation
- Blood analysis
- Smart transmitters
- Liquid/gas chromatography
- 6-digit DVM (Digital Voltmeter)
Q & A
- What is the AD7794BRUZ?
The AD7794BRUZ is a 24-bit Sigma-Delta Analog-to-Digital Converter (ADC) designed for high-precision measurement applications.
- What is the temperature range of the AD7794BRUZ?
The temperature range for B-grade parts is -40°C to +105°C, and for C-grade parts, it is -40°C to +125°C.
- What is the power supply range for the AD7794BRUZ?
The power supply range is from 2.7 V to 5.25 V.
- What types of interfaces does the AD7794BRUZ support?
The AD7794BRUZ supports SPI, QSPI, MICROWIRE, and DSP compatible 3-wire serial interfaces.
- What are the key features of the on-chip instrumentation amplifier?
The on-chip instrumentation amplifier is low noise, allowing direct interfacing of small amplitude signals to the ADC.
- Can the AD7794BRUZ operate with external references?
Yes, it can accept up to two external differential references.
- What is the typical current consumption of the AD7794BRUZ?
The typical current consumption is 400 μA.
- What are some of the applications of the AD7794BRUZ?
Applications include temperature measurement, pressure measurement, weigh scales, strain gage transducers, and more.
- Does the AD7794BRUZ have built-in power management features?
Yes, it includes a low-side power switch to power down bridge sensors between conversions, minimizing power consumption.
- How does the AD7794BRUZ handle noise and interference?
The device features simultaneous 50 Hz/60 Hz rejection and a low noise design to minimize interference.
