Overview
The AD8138ARZ, produced by Analog Devices Inc., is a low distortion differential ADC driver that significantly advances differential signal processing beyond traditional op amps. Manufactured on the proprietary ADI XFCB bipolar process, this component is designed to simplify differential signal amplification and driving. It can be used as a single-ended-to-differential amplifier or as a differential-to-differential amplifier, making it as easy to use as a standard op amp. The AD8138ARZ features a −3 dB bandwidth of 320 MHz and delivers a differential signal with the lowest harmonic distortion available in a differential amplifier, making it ideal for high-performance applications.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| −3 dB Bandwidth | VOUT = 0.5 V p-p, CF = 0 pF | 280 | 310 | MHz | |
| Large Signal Bandwidth | VOUT = 2 V p-p, CF = 0 pF | 265 | MHz | ||
| Input Resistance (Differential) | 6 MΩ | ||||
| Input Resistance (Common Mode) | 3 MΩ | ||||
| Input Capacitance | 1 pF | ||||
| Common-Mode Rejection Ratio (CMRR) | ΔVOUT, dm/ΔVIN, cm; ΔVIN, cm = ±1 V | -70 dB | -69 dB | ||
| Output Voltage Swing (Single-Ended) | 7.75 V p-p | ||||
| Operating Temperature Range | -55°C | +105°C |
Key Features
- Low harmonic distortion, making it ideal for driving high-performance ADCs.
- Unique internal feedback feature for balanced output gain and phase matching, suppressing even order harmonics.
- High bandwidth of 320 MHz and high IP3, suitable for IF and baseband signal chains.
- Adjustable common-mode level of the differential output via the VOCM pin, facilitating level-shifting for single-supply ADCs.
- Fast overload recovery to preserve sampling accuracy.
- Available in SOIC and MSOP packages, operating over −40°C to +85°C temperatures, with the AD8138-EP version extending the range to −55°C to +105°C.
Applications
- Differential signal amplification and driving in communication systems.
- Driving state-of-the-art 10-bit to 16-bit ADCs at high frequencies.
- Gain block in IF and baseband signal chains.
- Signal processing and data acquisition applications.
- Defense and aerospace applications with the AD8138-EP version.
Q & A
- What is the primary function of the AD8138ARZ?
The AD8138ARZ is a low distortion differential ADC driver that can be used as a single-ended-to-differential amplifier or as a differential-to-differential amplifier.
- What is the bandwidth of the AD8138ARZ?
The AD8138ARZ has a −3 dB bandwidth of 320 MHz.
- How does the AD8138ARZ handle harmonic distortion?
The AD8138ARZ features a unique internal feedback circuit that suppresses even order harmonics and minimizes gain error associated with external gain setting resistors.
- What is the operating temperature range of the AD8138ARZ?
The standard AD8138ARZ operates over −40°C to +85°C, while the AD8138-EP version extends this range to −55°C to +105°C.
- How does the AD8138ARZ facilitate level-shifting for ADCs?
The AD8138ARZ allows adjustable common-mode level of the differential output via the VOCM pin, making it easy to level-shift input signals for driving single-supply ADCs.
- What are some common applications of the AD8138ARZ?
Common applications include differential signal amplification in communication systems, driving high-performance ADCs, and use as a gain block in IF and baseband signal chains.
- What packages is the AD8138ARZ available in?
The AD8138ARZ is available in both SOIC and MSOP packages.
- How does the AD8138ARZ improve the performance of ADCs?
The differential output of the AD8138ARZ helps balance the input to differential ADCs, maximizing the performance of the ADC.
- What is the significance of the VOCM pin in the AD8138ARZ?
The VOCM pin allows for the adjustment of the common-mode level of the differential output, facilitating level-shifting for single-supply ADCs.
- How does the AD8138ARZ handle overload recovery?
The AD8138ARZ features fast overload recovery to preserve sampling accuracy.
