Overview
The AD7878AQ, produced by Analog Devices Inc., is a high-performance, 12-bit analog-to-digital converter (ADC) designed with a versatile digital signal processing (DSP) interface. This component integrates a complete A/D function, including an on-chip track/hold circuit, an on-chip reference, and a 12-bit successive approximation register (SAR) ADC. The AD7878AQ features an 8-word first-in, first-out (FIFO) memory and associated control logic, which significantly reduces software overhead in DSP applications. Fabricated using Linear Compatible CMOS (LC2MOS) technology, this ADC combines precision bipolar circuits with low-power CMOS logic, making it suitable for a wide range of high-speed applications.
Key Specifications
| Parameter | Value | Units | Comments |
|---|---|---|---|
| Number of Bits | 12 | ||
| Sampling Rate | 100 kHz | ||
| Number of Inputs | 1 | Single-ended input | |
| Data Interface | DSP | Compatible with DSP processors and 16-bit microprocessors | |
| Configuration | S/H-ADC | Sample and Hold ADC | |
| Reference Type | Internal | ||
| Voltage - Supply, Analog | ±5 V | ||
| Voltage - Supply, Digital | 5 V | ||
| Operating Temperature | –25°C to +85°C | For AD7878AQ version | |
| Package / Case | 28-CDIP (0.600", 15.24mm) | ||
| Signal-to-Noise Ratio (SNR) | 70 dB min | At 25°C, VIN = 10 kHz sine wave, fSAMPLE = 100 kHz | |
| Data Access Time | 41 ns max | ||
| Power Consumption | 60 mW typ |
Key Features
- Complete A/D Function with DSP Interface: Includes on-chip track/hold, on-chip reference, and 12-bit A/D converter.
- 8-Word FIFO Memory: Reduces software overhead by allowing up to eight samples to be digitized before microprocessor intervention.
- Fast Microprocessor Interface: Data access time of 41 ns, compatible with modern 16-bit microprocessors and DSP processors.
- Dynamic Specifications: Fully specified and tested for ac parameters such as signal-to-noise ratio, harmonic distortion, and intermodulation distortion.
- Low Power Consumption: Typical power consumption of 60 mW.
- Versatile Packaging: Available in 28-pin plastic and hermetic dual-in-line package (DIP), leadless ceramic chip carrier (LCCC), or plastic leaded chip carrier (PLCC).
Applications
- Digital Signal Processing: Suitable for various DSP applications due to its fast data access time and compatibility with DSP processors.
- Speech Recognition and Synthesis: Ideal for speech processing applications requiring high-speed and accurate analog-to-digital conversion.
- Spectrum Analysis: Used in spectrum analysis applications where dynamic parameters such as SNR and harmonic distortion are critical.
- High Speed Modems: Applicable in high-speed modem designs requiring fast and accurate data conversion.
- DSP Servo Control: Suitable for servo control systems that require precise and fast analog-to-digital conversion.
Q & A
- What is the resolution of the AD7878AQ ADC?
The AD7878AQ has a resolution of 12 bits. - What is the sampling rate of the AD7878AQ?
The sampling rate of the AD7878AQ is up to 100 kHz. - What type of input does the AD7878AQ support?
The AD7878AQ supports single-ended analog inputs. - What is the data interface type of the AD7878AQ?
The AD7878AQ features a DSP-compatible data interface. - What is the operating temperature range for the AD7878AQ?
The operating temperature range for the AD7878AQ is –25°C to +85°C. - What is the typical power consumption of the AD7878AQ?
The typical power consumption of the AD7878AQ is 60 mW. - What is the signal-to-noise ratio (SNR) of the AD7878AQ?
The SNR of the AD7878AQ is 70 dB min at 25°C with a 10 kHz sine wave input and a sampling frequency of 100 kHz. - What is the data access time of the AD7878AQ?
The data access time of the AD7878AQ is 41 ns max. - What are the packaging options for the AD7878AQ?
The AD7878AQ is available in 28-pin plastic and hermetic dual-in-line package (DIP), leadless ceramic chip carrier (LCCC), or plastic leaded chip carrier (PLCC). - What are some typical applications of the AD7878AQ?
The AD7878AQ is typically used in digital signal processing, speech recognition and synthesis, spectrum analysis, high-speed modems, and DSP servo control applications.
