Overview
The AD7890BR-10REEL, produced by Analog Devices Inc., is an 8-channel, 12-bit serial data acquisition system. This integrated circuit is fabricated using Analog Devices' Linear Compatible CMOS (LC2MOS) process, combining precision bipolar and CMOS technologies. The AD7890 features a high-speed 12-bit analog-to-digital converter (ADC), an input multiplexer, an on-chip track/hold amplifier, and a 2.5 V reference. It operates from a single 5 V supply and supports various analog input ranges, including ±10 V for the AD7890-10 version. The device is designed for low-power operation and includes a power-down mode for reduced power consumption.
Key Specifications
| Parameter | Value | Unit | Comments |
|---|---|---|---|
| Conversion Time | 5.9 | μs | fCLK IN = 2.5 MHz, MUX OUT connected to SHA IN |
| Track/Hold Acquisition Time | 2 | μs | Maximum |
| Analog Input Range | ±10 V | For AD7890-10 version | |
| Reference Voltage | 2.5 | V | Nominal |
| Reference Voltage Error @ 25°C | ±10 | mV | Maximum |
| Input Impedance | 1.6 kΩ | Minimum | |
| Input Capacitance | 10 pF | Maximum | |
| Logic Input High Voltage | 2.4 V | Minimum, VDD = 5 V ± 5% | |
| Logic Input Low Voltage | 0.8 V | Maximum, VDD = 5 V ± 5% | |
| Supply Voltage | 5 V | Nominal ± 5% | |
| Normal Mode Power Dissipation | 50 mW | Maximum, typically 30 mW | |
| Standby Mode Power Dissipation @ 25°C | 75 μW | Typical |
Key Features
- Fast 12-bit ADC with a conversion time of 5.9 μs
- Eight single-ended analog input channels
- Selection of input ranges: ±10 V, 0 V to 4.096 V, and 0 V to 2.5 V
- On-chip track/hold amplifier and 2.5 V reference
- High-speed, flexible, serial interface
- Single supply, low-power operation (50 mW maximum)
- Power-down mode (75 μW typical)
- Independently accessible multiplexer for inserting antialiasing filters or signal conditioning
- Adjustable multiplexer settling time using an external capacitor
- On-chip control register for channel selection, conversion start, and power-down via the serial port
Applications
The AD7890BR-10REEL is suitable for various applications requiring high-precision data acquisition, such as:
- Industrial automation and control systems
- Medical devices and diagnostic equipment
- Aerospace and defense systems
- Automotive systems and sensors
- Test and measurement instruments
Q & A
- What is the conversion time of the AD7890 ADC?
The conversion time of the AD7890 ADC is 5.9 μs.
- How many analog input channels does the AD7890 have?
The AD7890 has eight single-ended analog input channels.
- What are the available input ranges for the AD7890?
The available input ranges are ±10 V, 0 V to 4.096 V, and 0 V to 2.5 V.
- Does the AD7890 support power-down mode?
Yes, the AD7890 supports a power-down mode with a typical power dissipation of 75 μW at 25°C.
- What is the supply voltage for the AD7890?
The supply voltage for the AD7890 is 5 V nominal ± 5%.
- Can the multiplexer be accessed independently?
Yes, the multiplexer on the AD7890 is independently accessible, allowing for the insertion of antialiasing filters or signal conditioning.
- How does the AD7890 interface with other devices?
The AD7890 interfaces via a high-speed, flexible, serial interface that is compatible with serial ports on microcontrollers and digital signal processors.
- What is the typical power dissipation in normal mode?
The typical power dissipation in normal mode is 30 mW, with a maximum of 50 mW.
- Is the AD7890 suitable for high-precision applications?
Yes, the AD7890 is specified for both dc accuracy and dynamic performance parameters, making it suitable for high-precision applications.
- What types of packages are available for the AD7890?
The AD7890 is available in various packages, including PDIP, SOIC (wide), and CerDIP.
