AD7730BNZ

The AD7730BNZ is a CMOS, 24-bit Sigma-Delta (Σ-Δ) bridge sensor analog-to-digital converter (ADC) designed for load cell applications. It directly accepts low-level signals from a transducer and outputs a serial digital word. The input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by a low-pass programmable digital filter, allowing adjustment of filter cutoff, output rate, and settling time.

Key features of the AD7730BNZ include:

• Dual Buffered Differential Programmable Gain Analog Inputs: The device features two buffered differential programmable gain analog inputs as well as a differential reference input.
• Wide Input Range: It accepts four unipolar analog input ranges (0 mV to ±10 mV, +20 mV, +40 mV, and +80 mV) and four bipolar ranges (±10 mV, ±20 mV, ±40 mV, and ±80 mV).
• High Resolution: The peak-to-peak resolution achievable directly from the part is 1 in 230,000 counts.
• On-Chip DAC: An on-chip 6-bit DAC allows the removal of tare voltages.
• Clock Signals for Bridge Excitation: Clock signals for synchronizing AC excitation of the bridge are also provided.
• Serial Interface: The serial interface on the part can be configured for three-wire operation and is compatible with microcontrollers and digital signal processors.
• Self-Calibration and System Calibration Options: The AD7730BNZ contains self-calibration and system calibration options, featuring an offset drift of less than 5 nV/°C and a gain drift of less than 2 ppm/°C.
• Package Options: The device is available in a 24-pin plastic DIP, a 24-lead SOIC, and a 24-lead TSSOP package.

Additionally, the AD7730BNZ operates from a single +5 V supply (with a minimum supply voltage of 2.7 V and a maximum of 5.25 V) and has a power consumption of 125 mW. It has a sampling rate of 1.2 kSPS (kilo samples per second) and an input impedance of 9 GΩ. The device operates over a temperature range of -40 °C to +85 °C and is RoHS compliant.

In summary, the AD7730BNZ is a versatile and high-performance ADC designed for load cell and other bridge sensor applications. Its high resolution, programmable gain, and low-pass digital filter make it suitable for precision measurement and data processing tasks.