Overview
The AD7845JP, produced by Analog Devices Inc., is a groundbreaking 12-bit multiplying Digital-to-Analog Converter (DAC) that integrates an on-chip output amplifier. This device is the industry’s first to offer full 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 AD7845JP is designed for simplicity in microprocessor interfacing, with standard CS and WR signals controlling the latches, and all digital inputs being TTL and 5 V CMOS compatible.
Key Specifications
| Parameter | Value | 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) | 0°C to +70°C |
| Temperature Range | 0°C to +70°C | |
| Package | 28-terminal LCC and PLCC, 24-terminal SOIC | |
| Output Amplifier | Internally compensated, ±10 V into a 2 kΩ load | Settles to 0.01% FSR (1/2 LSB) in less than 5 µs |
| Input Offset Voltage | Low due to laser trimming at wafer level | |
| Slew Rate | Typically 11 V/µs | |
| Supply Voltage | VDD = +15 V ± 5%, VSS = –15 V ± 5% |
Key Features
- 12-Bit CMOS MDAC with Output Amplifier: Provides high resolution and precision voltage output.
- 4-Quadrant Multiplication: Full multiplying capability, allowing for both positive and negative voltage outputs.
- Guaranteed Monotonic: Ensures that the output voltage increases monotonically with the digital input code over the entire temperature range.
- Space-Saving Packages: Available in skinny 24-lead DIP, 28-terminal LCC and PLCC, and 24-terminal SOIC packages.
- Application Resistors On Chip: Three matched application resistors for gain ranging, voltage offsetting, etc.
- Low Power LC2MOS: Efficient power consumption using the LC2MOS process.
Applications
- Automatic Test Equipment: Ideal for precision measurement and control in test equipment.
- Digital Attenuators: Used in signal processing and communication systems for precise attenuation control.
- Programmable Power Supplies: Enables precise voltage control in power supply applications.
- Programmable Gain Amplifiers: Suitable for applications requiring adjustable gain settings.
- Digital-to-4–20 mA Converters: Used in industrial control systems for converting digital signals to analog current outputs.
Q & A
- What is the resolution of the AD7845JP?
The AD7845JP has a resolution of 12 bits, which means it can produce 4096 different output voltage levels.
- What is the temperature range for the AD7845JP?
The AD7845JP operates over a temperature range of 0°C to +70°C.
- What types of packages are available for the AD7845JP?
The AD7845JP is available in 28-terminal LCC and PLCC, and 24-terminal SOIC packages.
- How does the output amplifier of the AD7845JP perform?
The output amplifier can supply ±10 V into a 2 kΩ load, is internally compensated, and settles to 0.01% FSR (1/2 LSB) in less than 5 µs.
- What is the slew rate of the AD7845JP's output amplifier?
The slew rate of the output amplifier is typically 11 V/µs.
- How do the application resistors on the AD7845JP function?
The three matched application resistors on the AD7845JP provide facilities for gain ranging, voltage offsetting, etc..
- Is the AD7845JP compatible with microprocessors?
Yes, the AD7845JP is designed for simple microprocessor interfacing with standard CS and WR signals controlling the latches.
- What are some common applications of the AD7845JP?
The AD7845JP is used in automatic test equipment, digital attenuators, programmable power supplies, programmable gain amplifiers, and digital-to-4–20 mA converters.
- How does the LC2MOS process benefit the AD7845JP?
The LC2MOS process allows for the integration of precision linear components and digital circuitry on the same chip, enhancing performance and reducing power consumption.
- What is the input offset voltage characteristic of the AD7845JP's amplifier?
The input offset voltage of the amplifier is low due to laser trimming at the wafer level.
