Overview
The AD7781BRUZ, produced by Analog Devices Inc., is a 20-bit, pin-programmable, ultralow power sigma-delta analog-to-digital converter (ADC). This device is particularly suited for low-frequency measurement applications, such as bridge sensor systems, due to its low power consumption and high precision. The AD7781 operates with a power supply ranging from 2.7 V to 5.25 V and is available in a narrow body, 14-lead SOIC package and a 16-lead TSSOP package.
Key Specifications
| Parameter | Value |
|---|---|
| Resolution | 20 bits |
| Power Consumption | 330 μA |
| Power Supply | 2.7 V to 5.25 V |
| Input Range | ±5 V or ±39 mV (with PGA gain of 1 or 128) |
| Output Data Rate | 10 Hz or 16.7 Hz |
| Settling Time | 120 ms (at 16.7 Hz), 300 ms (at 10 Hz) |
| Filter Response | Superior dynamic performance at 16.7 Hz, better than -45 dB stop-band attenuation at 10 Hz |
| Package | 14-lead SOIC, 16-lead TSSOP |
| RMS Noise | 44 nV (at 10 Hz with gain of 128) |
Key Features
- Low power consumption: 330 μA, with a power-down mode to extend battery life.
- Pin-programmable features for ease of use.
- On-chip PGA with gain of 1 or 128.
- Simultaneous 50 Hz/60 Hz rejection at both output data rates.
- On-board clock, eliminating the need for an external clock.
- Low noise instrumentation amplifier and analog modulator.
- Dedicated pins for controlling all features.
- Eight status bits appended to the 20-bit conversion for data validity confirmation.
Applications
The AD7781 is designed for low-frequency measurement applications, particularly in bridge sensor systems such as load cells, pressure sensors, and strain gauges. Its low power consumption and high precision make it suitable for portable or battery-operated products. Additionally, the device's ability to reject low-frequency mechanical vibrations and simultaneous 50 Hz/60 Hz rejection makes it ideal for applications requiring high accuracy and noise rejection.
Q & A
- What is the resolution of the AD7781? The AD7781 has a resolution of 20 bits.
- What is the power consumption of the AD7781? The AD7781 consumes 330 μA.
- What are the available output data rates for the AD7781? The output data rates are 10 Hz and 16.7 Hz.
- What is the gain range of the on-chip PGA? The on-chip PGA has a gain of 1 or 128.
- What are the package options for the AD7781? The AD7781 is available in 14-lead SOIC and 16-lead TSSOP packages.
- Does the AD7781 have simultaneous 50 Hz/60 Hz rejection? Yes, the AD7781 provides simultaneous 50 Hz/60 Hz rejection at both output data rates.
- What is the settling time at the 10 Hz update rate? The settling time is 300 ms at the 10 Hz update rate.
- What is the RMS noise at the 10 Hz update rate with a gain of 128? The RMS noise is 44 nV at the 10 Hz update rate with a gain of 128.
- Does the AD7781 require an external clock? No, the AD7781 has an on-board clock, eliminating the need for an external clock.
- What type of filter response does the AD7781 offer? The AD7781 offers superior dynamic performance at the 16.7 Hz update rate and better than -45 dB stop-band attenuation at the 10 Hz update rate.
