Overview
The AD7821BQ is a high-speed, 8-bit, microprocessor-compatible analog-to-digital converter (ADC) produced by Analog Devices Inc. It is designed to offer improved performance over its predecessor, the AD7820, with a faster conversion time and higher signal bandwidth. The AD7821BQ features a built-in track-and-hold function, allowing it to digitize full-scale signals up to 100 kHz. It operates on either bipolar or unipolar input signals and is fabricated using Analog Devices’ Linear Compatible CMOS (LC2MOS) process, combining precision bipolar circuits with low power CMOS logic.
Key Specifications
| Parameter | Value |
|---|---|
| Resolution | 8 bits |
| Conversion Time | 660 ns (WR-RD mode), 700 ns (RD mode) |
| Signal Bandwidth | 100 kHz |
| Input Signal Type | Bipolar or Unipolar |
| Supply Voltage | ±5 V or single +5 V |
| Operating Temperature Range | –40°C to +85°C (AD7821BQ) |
| Power Dissipation | 50 mW |
| Package Type | 20-lead CDIP |
Key Features
- Fast conversion time using half-flash conversion technique
- Built-in track-and-hold function capable of digitizing signals up to 100 kHz
- Standard microprocessor control signals (CS, RD, WR, RDY, INT)
- Latched, three-state data outputs for high-speed data buses
- Overflow output (OFL) for cascading devices to achieve higher resolution
- Low power dissipation of 50 mW
- LC2MOS fabrication process combining precision bipolar circuits with low power CMOS logic
Applications
The AD7821BQ is suitable for a variety of high-speed data acquisition applications, including:
- High-speed data logging systems
- Medical imaging and diagnostic equipment
- Aerospace and defense systems requiring high-speed ADCs
- Industrial control and automation systems
- Test and measurement instruments
Q & A
- What is the resolution of the AD7821BQ ADC?
The AD7821BQ has an 8-bit resolution. - What is the conversion time of the AD7821BQ?
The conversion time is 660 ns in the WR-RD mode and 700 ns in the RD mode. - What is the maximum signal bandwidth the AD7821BQ can handle?
The AD7821BQ can handle signals up to 100 kHz. - Can the AD7821BQ operate with bipolar input signals?
Yes, the AD7821BQ can operate with both bipolar and unipolar input signals. - What is the operating temperature range for the AD7821BQ?
The operating temperature range for the AD7821BQ is –40°C to +85°C. - How much power does the AD7821BQ dissipate?
The AD7821BQ dissipates 50 mW of power. - What type of package does the AD7821BQ come in?
The AD7821BQ comes in a 20-lead CDIP package. - Does the AD7821BQ have a built-in track-and-hold function?
Yes, the AD7821BQ has a built-in track-and-hold function. - Can the AD7821BQ be cascaded to achieve higher resolution?
Yes, the AD7821BQ has an overflow output (OFL) for cascading devices to achieve higher resolution. - What fabrication process is used for the AD7821BQ?
The AD7821BQ is fabricated using Analog Devices’ Linear Compatible CMOS (LC2MOS) process.
