Overview
The AD7845JP-REEL, produced by Analog Devices Inc., is a groundbreaking 12-bit multiplying Digital-to-Analog Converter (DAC) that integrates an on-chip amplifier. This device is the industry’s first to offer 4-quadrant multiplying capability, making it highly versatile for various applications. Fabricated using the LC2MOS process, it combines precision linear components and digital circuitry on a single chip, enhancing performance and reducing component count. The AD7845 is available in several space-saving packages, including 24-lead 0.3" DIP, 28-terminal LCC and PLCC, and 24-terminal SOIC, making it ideal for applications where space is limited.
Key Specifications
| Parameter | Value | Units | Test Conditions/Comments |
|---|---|---|---|
| Resolution | 12 | Bits | 1 LSB = VREF / 2^12 = 2.4 mV |
| Relative Accuracy | ±1 LSB (J Version), ±1/2 LSB (K Version) | - | TMIN to TMAX unless otherwise noted |
| Output Voltage Range | ±10 V | V | Into a 2 kΩ load |
| Settling Time | < 5 µs | µs | To 0.01% FSR (1/2 LSB) |
| Input Offset Voltage | Low due to laser trimming at wafer level | - | - |
| Amplifier Slew Rate | Typically 11 V/µs | V/µs | - |
| Digital Inputs Compatibility | TTL, HCMOS, and +5 V CMOS | - | - |
| Operating Temperature Range | 0°C to +70°C | °C | - |
Key Features
- 12-Bit CMOS MDAC with Output Amplifier: Provides high resolution and precision.
- 4-Quadrant Multiplication: Enables full 4-quadrant multiplying capability.
- Guaranteed Monotonic: Ensures monotonic behavior over the entire temperature range.
- Space-Saving Packages: Available in 24-lead 0.3" DIP, 28-terminal LCC and PLCC, and 24-terminal SOIC packages.
- On-Chip Application Resistors: Allows for gain ranging and other applications.
- Low Power LC2MOS Process: Combines precision linear components and digital circuitry on a single chip.
Applications
- Automatic Test Equipment: Used for precise signal generation.
- Digital Attenuators: Provides accurate attenuation control.
- Programmable Power Supplies: Enables precise voltage control.
- Programmable Gain Amplifiers: Offers adjustable gain settings.
- Digital-to-4–20 mA Converters: Converts digital signals to current outputs.
Q & A
- What is the resolution of the AD7845JP-REEL?
The AD7845JP-REEL has a 12-bit resolution, which translates to 4096 possible output levels.
- What is the output voltage range of the AD7845JP-REEL?
The output voltage range is ±10 V into a 2 kΩ load.
- How does the AD7845JP-REEL achieve 4-quadrant multiplication?
The device uses a segmented scheme where the 2 MSBs of the 12-bit data word are decoded to drive switches, and the remaining 10 bits drive switches in a standard R-2R ladder configuration.
- What is the settling time of the AD7845JP-REEL?
The settling time is less than 5 µs to 0.01% FSR (1/2 LSB).
- Is the AD7845JP-REEL compatible with microprocessors?
Yes, all digital inputs are TTL, HCMOS, and +5 V CMOS compatible, facilitating easy microprocessor interfacing.
- What are the typical applications of the AD7845JP-REEL?
Typical applications include automatic test equipment, digital attenuators, programmable power supplies, programmable gain amplifiers, and digital-to-4–20 mA converters.
- What is the operating temperature range of the AD7845JP-REEL?
The operating temperature range is 0°C to +70°C.
- How is the output amplifier compensated in the AD7845JP-REEL?
The output amplifier is internally compensated, and its input offset voltage is low due to laser trimming at wafer level.
- What is the slew rate of the amplifier in the AD7845JP-REEL?
The amplifier slew rate is typically 11 V/µs.
- What packages are available for the AD7845JP-REEL?
The device is available in 24-lead 0.3" DIP, 28-terminal LCC and PLCC, and 24-terminal SOIC packages.
