Overview
The AD7730BRZ, produced by Analog Devices Inc., is a comprehensive analog front end designed specifically for weigh-scale and pressure measurement applications. This device accepts low-level signals directly from a transducer and outputs a serial digital word. It features a proprietary programmable gain front end based around an analog modulator, which processes the input signal. The modulator output is further processed by a low-pass programmable digital filter, allowing adjustments in filter cutoff, output rate, and settling time. The AD7730BRZ operates from a single +5V supply and is compatible with microcontrollers and digital signal processors through its serial interface, which can be configured for three-wire operation.
Key Specifications
| Parameter | Value | Conditions/Comments |
|---|---|---|
| Resolution | 24 bits | |
| Input Ranges | 0 to ±10 mV, ±20 mV, ±40 mV, ±80 mV (bipolar); 0 to +10 mV, +20 mV, +40 mV, +80 mV (unipolar) | |
| Peak-to-Peak Resolution | 1 in 230,000 counts | |
| Offset Drift | 5 nV/°C | |
| Gain Drift | 2 ppm/°C | |
| Line Frequency Rejection | < 150 dB | |
| Supply Voltage | 2.7 V to 5.25 V | |
| Operating Temperature Range | -40°C to +85°C | |
| Package Style | 24-lead SOIC (Wide) | |
| Sampling Rate | Up to 1.2 kSPS | |
| Interface | Serial, SPI | Three-wire operation |
Key Features
- Two buffered differential programmable gain analog inputs and a differential reference input.
- On-chip 6-bit DAC for offset/TARE removal.
- Programmable digital filter allowing adjustment of filter cutoff, output rate, and settling time.
- FASTStep™ mode for fast step response.
- AC or DC excitation with clock signals for synchronizing AC excitation of the bridge.
- Self-calibration and system calibration options.
- Single supply operation with reference voltages of 1V to 5V.
- Compatibility with microcontrollers and digital signal processors through a serial interface.
Applications
The AD7730BRZ is widely used in various applications, including:
- Weigh scales: Ideal for converting low-level signals from load cells into digital data.
- Pressure measurement: Suitable for pressure transducers, providing accurate and stable readings.
Q & A
- What is the primary function of the AD7730BRZ?
The AD7730BRZ is a complete analog front end designed for converting low-level signals from transducers into serial digital words, primarily used in weigh-scale and pressure measurement applications.
- What is the resolution of the AD7730BRZ?
The AD7730BRZ has a 24-bit resolution, achieving a peak-to-peak resolution of 1 in 230,000 counts.
- What are the input ranges supported by the AD7730BRZ?
The device supports both unipolar and bipolar input ranges: 0 to ±10 mV, ±20 mV, ±40 mV, and ±80 mV.
- What is the offset drift and gain drift of the AD7730BRZ?
The offset drift is less than 5 nV/°C, and the gain drift is less than 2 ppm/°C).
- What types of excitation does the AD7730BRZ support?
The device supports both AC and DC excitation with clock signals for synchronizing AC excitation of the bridge).
- What is the operating temperature range of the AD7730BRZ?
The operating temperature range is -40°C to +85°C).
- What is the package style of the AD7730BRZ?
The AD7730BRZ is available in a 24-lead SOIC (Wide) package).
- What is the sampling rate of the AD7730BRZ?
The sampling rate can be up to 1.2 kSPS).
- Is the AD7730BRZ compatible with microcontrollers and digital signal processors?
Yes, the device is compatible with microcontrollers and digital signal processors through its serial interface, which can be configured for three-wire operation).
- What calibration options are available on the AD7730BRZ?
The device features self-calibration and system calibration options).
