Overview
The AD7711AQ, produced by Analog Devices Inc., is a comprehensive analog front end designed for low-frequency measurement applications. This device is capable of accepting low-level signals directly from transducers and outputting a serial digital word. It utilizes a sigma-delta conversion technique to achieve up to 24 bits of no missing codes performance, ensuring high accuracy and reliability. The AD7711AQ features a programmable gain front end, on-chip digital filter, and two current sources for RTD excitation in 3-wire and 4-wire configurations. It is ideal for use in smart, microcontroller-based systems due to its software-configurable gain settings, signal polarity, input channel selection, and RTD current control via a bidirectional serial port.
Key Specifications
| Parameter | Value |
|---|---|
| Number of Bits | 24 |
| Sampling Rate | 19.5 ksps |
| Input Channels | 2 (1 differential, 1 single-ended) |
| Supply Voltage | 4.75 V to 5.25 V |
| Operating Temperature | -40°C to +85°C (AD7711AQ) |
| Package Type | 24-lead CerDIP (Narrow 0.3 Inch) |
| Power Consumption | 25 mW typical, 7 mW in power-down mode |
| Interface | SPI, Serial |
| Polarity | Bipolar, Unipolar |
Key Features
- Programmable gain front end to accept input signals directly from RTD transducers, reducing the need for additional signal conditioning.
- No missing codes ensure true 23-bit dynamic range with excellent ±0.0015% accuracy and on-chip self-calibration to eliminate temperature drift effects.
- On-chip digital filter with programmable filter cutoff and settling time via the on-chip control register.
- Two current sources for RTD excitation in 3-wire and 4-wire configurations.
- Software-configurable gain settings, signal polarity, input channel selection, and RTD current control using a bidirectional serial port.
- Self-measurement calibration, system calibration, and background calibration options, with the ability to read and write on-chip calibration registers.
- Low power consumption (25 mW typical) with a software-programmable power-down mode reducing standby power to 7 mW typical.
Applications
- RTD transducers and temperature measurement systems.
- Process control and smart transmitters.
- Portable industrial instruments.
- Microcontroller or DSP processor-based systems.
Q & A
- What is the resolution of the AD7711AQ?
The AD7711AQ has a resolution of up to 24 bits with no missing codes performance.
- What is the sampling rate of the AD7711AQ?
The sampling rate of the AD7711AQ is 19.5 ksps.
- What types of input channels does the AD7711AQ have?
The AD7711AQ features one differential analog input and one single-ended analog input, along with a differential reference input.
- What is the operating temperature range of the AD7711AQ?
The operating temperature range of the AD7711AQ is -40°C to +85°C.
- How is the power consumption of the AD7711AQ?
The AD7711AQ consumes 25 mW typical power and can be reduced to 7 mW in power-down mode.
- What interface does the AD7711AQ use?
The AD7711AQ uses an SPI, serial interface.
- Can the AD7711AQ be used in single-supply or dual-supply configurations?
Yes, the AD7711AQ can be operated from a single supply or a dual supply, allowing it to convert signals down to -VREF on its inputs.
- What calibration options are available on the AD7711AQ?
The AD7711AQ offers self-measurement calibration, system calibration, and background calibration options, and allows reading and writing of on-chip calibration registers.
- What types of RTD configurations does the AD7711AQ support?
The AD7711AQ supports 3-wire and 4-wire RTD configurations with on-chip current sources for excitation.
- What is the package type of the AD7711AQ?
The AD7711AQ is available in a 24-lead CerDIP (Narrow 0.3 Inch) package.
