Overview
The AD7730BR-REEL, produced by Analog Devices Inc., is a comprehensive analog front end (AFE) designed specifically for weigh-scale and pressure measurement applications. This device is capable of accepting low-level signals directly from transducers and converting them into a serial digital output. It features a proprietary programmable gain front end based on an analog modulator, which is followed by a low-pass programmable digital filter. This configuration allows for the adjustment of filter cutoff, output rate, and settling time. The AD7730 operates from a single +5 V supply and supports various analog input ranges, both unipolar and bipolar, making it versatile for different measurement scenarios.
Key Specifications
| Parameter | Value | Conditions/Comments |
|---|---|---|
| Number of Bits | 24 | |
| Number of Channels | 2 | |
| Input Type | Differential, Single-Ended | |
| Operating Temperature Range | -40°C to 85°C | |
| Sample Rate (max) | 1.2 kSPS | |
| Power (typ) | 125 mW | |
| Voltage - Supply, Analog | +5 V | |
| Voltage - Supply, Digital | 2.7 V ~ 5.25 V | |
| Package | 24-Lead SOIC (Wide) or 24-Lead TSSOP | |
| Data Output Interface | Serial SPI | |
| Device Architecture | Sigma-Delta |
Key Features
- Programmable gain front end with two buffered differential analog inputs and a differential reference input.
- On-chip 6-bit DAC for offset/TARE removal.
- FASTStep™ mode for AC or DC excitation.
- Self-calibration and system calibration options.
- Low offset drift of less than 5 nV/°C and gain drift of less than 2 ppm/°C.
- Serial interface compatible with microcontrollers and digital signal processors, configurable for three-wire operation.
- Low-pass programmable digital filter for adjusting filter cutoff, output rate, and settling time.
Applications
- Weigh scales: The AD7730 is optimized for load cell applications, providing high accuracy and stability.
- Pressure measurement: Suitable for various pressure transducer applications due to its high precision and low noise characteristics.
- Bridge transducer applications: The device supports bridge transducers, making it ideal for applications requiring precise measurement of small signal changes.
Q & A
- What is the primary function of the AD7730?
The AD7730 is a complete analog front end designed for weigh-scale and pressure measurement applications, converting low-level signals from transducers into a serial digital output.
- What types of input signals does the AD7730 support?
The AD7730 supports both differential and single-ended input signals, with various unipolar and bipolar analog input ranges.
- What is the resolution of the AD7730?
The AD7730 achieves a peak-to-peak resolution of 1 in 230,000 counts.
- What is the operating temperature range of the AD7730?
The operating temperature range of the AD7730 is -40°C to 85°C.
- What is the power consumption of the AD7730?
The typical power consumption of the AD7730 is 125 mW.
- What types of packages are available for the AD7730?
The AD7730 is available in 24-lead PDIP, 24-lead SOIC (Wide), and 24-lead TSSOP packages.
- Does the AD7730 support self-calibration?
Yes, the AD7730 includes self-calibration and system calibration options.
- What is the significance of the FASTStep™ mode in the AD7730?
The FASTStep™ mode allows for AC or DC excitation, enhancing the device's flexibility in different measurement scenarios).
- How does the AD7730's serial interface work?
The serial interface of the AD7730 can be configured for three-wire operation and is compatible with microcontrollers and digital signal processors).
- What is the purpose of the on-chip 6-bit DAC in the AD7730?
The on-chip 6-bit DAC is used for the removal of TARE voltages).
