Overview
The AD8138AR, produced by Analog Devices Inc., is a low distortion differential ADC driver that significantly advances differential signal processing beyond traditional op amps. It can be used as either a single-ended-to-differential amplifier or a differential-to-differential amplifier. The AD8138AR is manufactured on the proprietary ADI XFCB bipolar process, making it easy to use and highly effective in simplifying differential signal amplification and driving.
This component is particularly useful for preserving low frequency and DC information when driving high-performance ADCs, eliminating the need for a transformer. It features high bandwidth, low harmonic distortion, and adjustable common-mode level, making it ideal for various signal processing and data acquisition applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Bandwidth | 320 | MHz |
| Supply Voltage | ±5 V | V |
| Operating Temperature | -40°C to +85°C | °C |
| Package Type | 8-SOIC, 8-MSOP | |
| Input Impedance | High | |
| Output Impedance | Low | |
| Harmonic Distortion | Lowest available in a differential amplifier |
Key Features
- High bandwidth of 320 MHz
- Low harmonic distortion, suppressing even order harmonics
- Internal feedback feature for balanced output gain and phase matching
- Adjustable common-mode level via the VOCM pin
- Fast overload recovery to preserve sampling accuracy
- Easy to use, similar to an op amp, but with enhanced differential signal processing capabilities
- No need for a transformer when driving high-performance ADCs
Applications
- Data acquisition systems
- Communication systems, particularly for driving 10-bit to 16-bit converters at high frequencies
- IF and baseband signal chains due to its high bandwidth and IP3
- Defense and aerospace applications (AD8138-EP model)
Q & A
- What is the primary function of the AD8138AR?
The AD8138AR is a differential ADC driver that can be used as a single-ended-to-differential amplifier or a differential-to-differential amplifier.
- What is the bandwidth of the AD8138AR?
The bandwidth of the AD8138AR is 320 MHz.
- What are the typical supply voltages for the AD8138AR?
The AD8138AR typically operates from ±5 V supply voltages.
- What are the available package types for the AD8138AR?
The AD8138AR is available in 8-SOIC and 8-MSOP packages.
- How does the AD8138AR handle harmonic distortion?
The AD8138AR features an internal feedback circuit that suppresses even order harmonics, resulting in the lowest harmonic distortion available in a differential amplifier.
- Can the AD8138AR be used for level-shifting?
Yes, the AD8138AR can perform DC coupling and level-shifting of bipolar signals without inverting the input signal.
- What are some common applications of the AD8138AR?
The AD8138AR is commonly used in data acquisition systems, communication systems, IF and baseband signal chains, and defense and aerospace applications.
- How does the AD8138AR improve ADC performance?
The AD8138AR helps balance the input to differential ADCs, maximizing the performance of the ADC by preserving low frequency and DC information.
- What is the operating temperature range of the AD8138AR?
The operating temperature range of the AD8138AR is -40°C to +85°C.
- Does the AD8138AR require a transformer to drive ADCs?
No, the AD8138AR eliminates the need for a transformer when driving high-performance ADCs.
