Overview
The AD7705BN, manufactured by Analog Devices Inc., is a 16-bit, 2-channel analog-to-digital converter (ADC) designed for low-frequency measurement applications. This device is part of the AD7705/AD7706 family and is known for its high accuracy and low power consumption. The AD7705BN operates from a single supply voltage of 2.7 V to 3.3 V or 4.75 V to 5.25 V, making it versatile for various system designs. It features a programmable gain front end and a sigma-delta (Σ-Δ) conversion technique, ensuring high precision and reliability in converting low-level input signals from transducers into digital output.
Key Specifications
| Parameter | Description |
|---|---|
| Number of Bits | 16 |
| Number of Channels | 2 (fully differential) |
| Sampling Rate | 500 samples per second (sps) |
| Input Type | Differential |
| Data Interface | SPI, DSP |
| Architecture | Sigma-Delta (Σ-Δ) |
| Reference Type | External |
| Voltage - Supply, 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 |
| Package | 16-lead PDIP, 16-lead SOIC, 16-lead TSSOP |
| Operating Temperature | −40°C to +85°C |
Key Features
- Programmable Gain Front End: Gains from 1 to 128, allowing for a wide range of input signal levels.
- Sigma-Delta Conversion: Ensures up to 16 bits of no missing codes performance and low rms noise (<600 nV).
- High Accuracy: ±0.003% nonlinearity and excellent static performance specifications.
- Low Power Consumption: Maximum power dissipation of 1 mW at 3 V and standby current of 8 μA.
- Flexible Input Ranges: Supports unipolar and bipolar input signal ranges, e.g., 0 mV to 20 mV, 0 V to 2.5 V, and ±20 mV through ±2.5 V.
- On-Chip Calibration: Removes zero-scale and full-scale errors, eliminating endpoint errors and temperature drift effects.
- 3-Wire Serial Interface: Compatible with SPI, QSPI, MICROWIRE, and DSP, reducing the number of interconnect lines and opto-couplers in isolated systems.
Applications
- Low Frequency Measurement: Ideal for applications requiring precise measurement of low-frequency signals, such as those from transducers.
- Microcontroller and DSP Systems: Suitable for integration with microcontrollers or DSP processors due to its 3-wire serial interface.
- Industrial Automation: Used in various industrial automation applications where high accuracy and reliability are crucial.
- Medical Devices: Applicable in medical devices that require precise analog-to-digital conversion.
- Test and Measurement Equipment: Employed in test and measurement equipment for its high precision and low noise characteristics.
Q & A
- What is the resolution of the AD7705BN ADC?
The AD7705BN has a resolution of 16 bits.
- How many analog input channels does the AD7705BN have?
The AD7705BN features two fully differential analog input channels.
- What are the supported supply voltage ranges for the AD7705BN?
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 dissipation of the AD7705BN at 3 V supply?
The maximum power dissipation is 1 mW at 3 V supply.
- What type of conversion technique does the AD7705BN use?
The AD7705BN employs a sigma-delta (Σ-Δ) conversion technique.
- What is the accuracy of the AD7705BN?
The device has an accuracy of ±0.003% nonlinearity.
- What are the package options available for the AD7705BN?
The device is available in 16-lead PDIP, 16-lead SOIC, and 16-lead TSSOP packages.
- What is the operating temperature range of the AD7705BN?
The operating temperature range is −40°C to +85°C.
- Does the AD7705BN support on-chip calibration?
Yes, the device features on-chip calibration to remove zero-scale and full-scale errors.
- What type of serial interface does the AD7705BN use?
The device uses a 3-wire serial interface compatible with SPI, QSPI, MICROWIRE, and DSP.
