Overview
The AD7874AR, produced by Analog Devices Inc., is a four-channel simultaneous sampling, 12-bit data acquisition system. This component is designed to preserve the relative phase information of the input channels, making it ideal for applications where such precision is crucial. The AD7874AR includes a high-speed 12-bit ADC, on-chip reference, on-chip clock, and four track/hold amplifiers. Each input channel has its own track/hold amplifier, allowing simultaneous sampling and maintaining the phase relationship between the channels. This feature is particularly beneficial in applications such as phased-array sonar and AC motor controllers.
Key Specifications
| Parameter | Value | Units | Test Conditions/Comments |
|---|---|---|---|
| Resolution | 12-bit | - | - |
| Number of Channels | 4 | - | - |
| Conversion Time per Channel | 8 µs | - | fCLK = 2.5 MHz external |
| Sample Rate for All Four Channels | 29 kHz | - | - |
| Input Range | ±10 V | - | - |
| Supply Voltage | ±5 V | - | - |
| Aperture Delay | Small and well matched across channels | - | < 4 ns |
| Package Types | 28-pin PDIP, 28-terminal LCCC, 28-pin SOIC | - | - |
Key Features
- Simultaneous sampling of four input channels, each with its own track/hold amplifier.
- Fast 12-bit ADC with 8 µs conversion time per channel.
- On-chip reference and on-chip clock.
- Tight aperture delay matching to preserve relative phase information.
- High-speed digital interface compatible with modern 16-bit microprocessors and digital signal processors.
- Input bandwidth of the track/hold amplifier greater than the Nyquist rate of the ADC.
- Small signal 3 dB cutoff frequency typically at 500 kHz.
Applications
- Phased-array sonar systems where relative phase information is critical.
- AC motor controllers requiring precise phase alignment.
- Adaptive filters and digital signal processing applications.
Q & A
- What is the resolution of the AD7874AR?
The AD7874AR has a 12-bit resolution.
- How many input channels does the AD7874AR support?
The AD7874AR supports four input channels.
- What is the conversion time per channel for the AD7874AR?
The conversion time per channel is 8 µs.
- What is the sample rate for all four channels of the AD7874AR?
The sample rate for all four channels is 29 kHz.
- What is the input voltage range of the AD7874AR?
The input voltage range is ±10 V.
- What are the supply voltage requirements for the AD7874AR?
The supply voltage requirements are ±5 V.
- What types of packages are available for the AD7874AR?
The AD7874AR is available in 28-pin PDIP, 28-terminal LCCC, and 28-pin SOIC packages.
- Why is the aperture delay matching important in the AD7874AR?
The aperture delay matching is crucial for preserving the relative phase information between different input channels and for allowing multiple AD7874s to sample more than four channels simultaneously.
- What is the significance of the on-chip reference and on-chip clock in the AD7874AR?
The on-chip reference and on-chip clock ensure stability and accuracy in the conversion process, allowing multiple AD7874s to be driven from the same reference source.
- In which applications is the AD7874AR particularly useful?
The AD7874AR is particularly useful in phased-array sonar systems, AC motor controllers, adaptive filters, and digital signal processing applications.
