Overview
The AD7878JN, manufactured by Analog Devices Inc., is a complete 12-bit analog-to-digital converter (ADC) designed for high-speed applications. This device features a versatile digital signal processing (DSP) interface, including an 8-word first-in, first-out (FIFO) memory and associated control logic. The AD7878JN is fabricated using Linear Compatible CMOS (LC2MOS) technology, which combines precision bipolar circuits with low-power CMOS logic. This ADC is fully specified for dynamic parameters such as signal-to-noise ratio, harmonic distortion, and intermodulation distortion, making it suitable for various high-performance applications.
Key Specifications
| Parameter | Value | Units | Comments |
|---|---|---|---|
| Number of Bits | 12 | - | - |
| Conversion Time | 7.125 µs | µs | For an 8 MHz input clock |
| Sample Rate | 100 kHz | kHz | - |
| Analog Input Voltage Range | ±3 V | V | Bipolar range |
| Signal-to-Noise Ratio (SNR) | 70 dB min | dB | At 25°C, VIN = 10 kHz sine wave, fSAMPLE = 100 kHz |
| Data Access Time | 41 ns | ns | Fast microprocessor interface |
| Operating Temperature Range | 0°C to +70°C | °C | Commercial temperature grade |
| Supply Voltage | +5 V ± 5% | V | - |
| Package Type | 28-pin DIP | - | Through-hole, plastic/epoxy body material |
Key Features
- Complete A/D Function with DSP Interface: The AD7878JN includes an on-chip track/hold, on-chip reference, and a 12-bit A/D converter, along with an 8-word FIFO to reduce software overhead in DSP applications.
- Dynamic Specifications: Fully specified and tested for AC parameters such as signal-to-noise ratio, harmonic distortion, and intermodulation distortion.
- Fast Microprocessor Interface: Data access time of 41 ns, making it compatible with modern 16-bit microprocessors and DSP processors.
- 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: Ideal for high-speed DSP applications due to its fast data access time and compatibility with DSP processors.
- Speech Recognition and Synthesis: Suitable for speech processing applications requiring high accuracy and speed.
- Spectrum Analysis: Used in spectrum analysis due to its dynamic specifications and high signal-to-noise ratio.
- High-Speed Modems: Applicable in high-speed modem designs requiring fast and accurate analog-to-digital conversion.
- DSP Servo Control: Used in servo control systems that require precise and rapid analog-to-digital conversion.
Q & A
- What is the resolution of the AD7878JN ADC?
The AD7878JN is a 12-bit analog-to-digital converter.
- What is the maximum sample rate of the AD7878JN?
The maximum sample rate of the AD7878JN is 100 kHz.
- What is the analog input voltage range of the AD7878JN?
The analog input voltage range is ±3 V.
- What is the signal-to-noise ratio (SNR) of the AD7878JN?
The SNR is 70 dB minimum at 25°C with a 10 kHz sine wave input and a sample rate of 100 kHz.
- What is the data access time of the AD7878JN?
The data access time is 41 ns.
- What are the operating temperature ranges for the AD7878JN?
The operating temperature range is 0°C to +70°C.
- What type of packaging is available for the AD7878JN?
The AD7878JN is available in 28-pin DIP, LCCC, and PLCC packages.
- What is the typical power consumption of the AD7878JN?
The typical power consumption is 60 mW.
- What are some common applications of the AD7878JN?
Common applications include digital signal processing, speech recognition and synthesis, spectrum analysis, high-speed modems, and DSP servo control.
- Does the AD7878JN have a built-in FIFO memory?
Yes, the AD7878JN includes an 8-word FIFO memory to reduce software overhead in DSP applications.
