Overview
The AD7705BR, produced by Analog Devices Inc., is a 16-bit, low-power, Sigma-Delta Analog-to-Digital Converter (ADC) designed for low-frequency measurement applications. This device is part of the AD7705/AD7706 family, which offers a complete analog front end for direct connection to transducers, providing all necessary signal conditioning and conversion. The AD7705BR features two fully differential analog input channels, making it ideal for use in smart, microcontroller, or DSP-based systems. It operates from a single supply voltage of 2.7 V to 3.3 V or 4.75 V to 5.25 V and consumes a maximum of 1 mW of power at 3 V, making it suitable for battery-powered or loop-powered applications.
Key Specifications
| Parameter | Value |
|---|---|
| Number of Bits | 16 |
| Number of Input Channels | 2 (fully differential) |
| Input Type | Differential |
| Supply Voltage (Analog/Digital) | 2.7 V to 3.3 V, 4.75 V to 5.25 V |
| Power Dissipation | 1 mW maximum @ 3 V |
| Standby Current | 8 μA maximum |
| Operating Temperature | -40°C to +85°C |
| Package Type | 16-lead SOIC, 16-lead TSSOP, 16-lead PDIP |
| Sampling Rate | Up to 500 samples per second |
| Data Interface | SPI, DSP, QSPI, MICROWIRE |
| Reference Type | External |
Key Features
- Programmable Gain Amplifier (PGA) with gain settings from 1 to 128, allowing for both low-level and high-level analog inputs without external signal conditioning hardware.
- On-chip digital filter with programmable notch frequency, enabling adjustment of the filter cutoff and output update rate.
- Self-calibration and system calibration options to eliminate gain and offset errors.
- Low power consumption (1 mW max @ 3 V) and low standby current (8 μA max), suitable for battery-powered or loop-powered applications.
- CMOS construction ensuring very low power dissipation.
- Differential reference inputs for maximum flexibility in ratiometric applications.
- 3-wire serial interface compatible with SPI, DSP, QSPI, and MICROWIRE.
Applications
The AD7705BR is ideal for use in various applications, including:
- Smart, microcontroller, or DSP-based systems requiring low-frequency measurement capabilities.
- Transducer interfaces where direct connection and signal conditioning are necessary.
- Low-power, battery-powered, or loop-powered systems due to its low power consumption.
- Ratiometric applications where differential reference inputs are beneficial.
Q & A
- What is the resolution of the AD7705BR ADC?
The AD7705BR has a resolution of 16 bits with no missing codes.
- How many input channels does the AD7705BR have?
The AD7705BR features two fully differential analog input channels.
- What is the operating voltage range of the AD7705BR?
The device operates from a single supply voltage of 2.7 V to 3.3 V or 4.75 V to 5.25 V.
- What is the maximum power consumption of the AD7705BR?
The maximum power consumption is 1 mW at 3 V.
- What types of interfaces does the AD7705BR support?
The device supports SPI, DSP, QSPI, and MICROWIRE interfaces.
- Does the AD7705BR have built-in calibration options?
Yes, it has self-calibration and system calibration options to eliminate gain and offset errors.
- What is the operating temperature range of the AD7705BR?
The operating temperature range is -40°C to +85°C.
- What package types are available for the AD7705BR?
The device is available in 16-lead SOIC, 16-lead TSSOP, and 16-lead PDIP packages.
- What is the sampling rate of the AD7705BR?
The sampling rate can be up to 500 samples per second.
- Is the AD7705BR suitable for low-power applications?
Yes, it is suitable due to its low power consumption and low standby current.
