Overview
The AD8138ARM, produced by Analog Devices Inc., is a low distortion differential ADC driver that significantly enhances differential signal processing compared to traditional op amps. It can function as either a single-ended-to-differential amplifier or a differential-to-differential amplifier. Manufactured using ADI's proprietary XFCB bipolar process, the AD8138ARM offers a -3 dB bandwidth of 320 MHz and delivers differential signals with minimal harmonic distortion. This component simplifies differential signal amplification and driving, making it as easy to use as an op amp while providing balanced output gain and phase matching through its unique internal feedback feature.
Key Specifications
| Parameter | Value |
|---|---|
| Bandwidth (-3 dB) | 320 MHz |
| Harmonic Distortion | Lowest available in a differential amplifier |
| Supply Voltage | ±5 V |
| Package Type | 8-TSSOP, 8-MSOP (0.118", 3.00mm Width) |
| Mounting Type | Surface Mount |
| Common-Mode Feedback | Adjustable via VOCM pin |
| Gain Setting | External resistors for differential feedback |
Key Features
- Unique internal feedback feature for balanced output gain and phase matching, suppressing even order harmonics.
- Eliminates the need for a transformer when driving high-performance ADCs, preserving low frequency and DC information.
- Adjustable common-mode level via the VOCM pin, allowing for easy level-shifting of input signals for single supply ADCs.
- Fast overload recovery to preserve sampling accuracy.
- High bandwidth and IP3, making it suitable for use as a gain block in IF and baseband signal chains.
Applications
- Data acquisition systems: The AD8138ARM is well-suited for a wide variety of signal processing and data acquisition applications due to its high performance and low distortion.
- Communication systems: Ideal for driving state-of-the-art 10-bit to 16-bit converters at high frequencies.
- IF and baseband signal chains: Its high bandwidth and IP3 make it appropriate for use as a gain block in these applications.
Q & A
- What is the primary function of the AD8138ARM?
The AD8138ARM is a low distortion differential ADC driver that can function as either a single-ended-to-differential amplifier or a differential-to-differential amplifier.
- What is the bandwidth of the AD8138ARM?
The AD8138ARM has a -3 dB bandwidth of 320 MHz.
- How does the AD8138ARM handle common-mode feedback?
The AD8138ARM has an adjustable common-mode feedback via the VOCM pin, allowing for easy level-shifting of input signals.
- What type of packages is the AD8138ARM available in?
The AD8138ARM is available in 8-TSSOP and 8-MSOP packages.
- What is the typical supply voltage for the AD8138ARM?
The AD8138ARM typically operates from ±5 V supplies.
- How does the AD8138ARM improve ADC performance?
The AD8138ARM helps balance the input to differential ADCs, maximizing the performance of the ADC by providing a highly balanced differential output.
- What are some common applications of the AD8138ARM?
The AD8138ARM is used in data acquisition systems, communication systems, and as a gain block in IF and baseband signal chains.
- How does the AD8138ARM handle harmonic distortion?
The AD8138ARM has a unique internal feedback feature that suppresses even order harmonics, providing the lowest harmonic distortion available in a differential amplifier.
- Does the AD8138ARM require a transformer for ADC driving?
No, the AD8138ARM eliminates the need for a transformer when driving high-performance ADCs.
- What is the significance of the VOCM pin in the AD8138ARM?
The VOCM pin allows for the adjustment of the common-mode level of the differential output, enabling easy level-shifting of input signals for single supply ADCs.
