AD8138AARZ-RL

Overview

The AD8138AARZ-RL is a low distortion differential ADC driver manufactured by Analog Devices Inc. It features a -3 dB bandwidth of 320 MHz at G = +1 and a slew rate of 1150 V/µs. The device settles to 0.01% in 16 ns with an overdrive recovery time of 4 ns. Input voltage noise is 5 nV/√Hz, and typical offset voltage is 1 mV. It operates on a wide supply range from +3 V to ±5 V with low power consumption of 90 mW at 5 V. The component is housed in an 8-Lead SOIC package.

Feature Summary

• Provides easy single-ended-to-differential conversion with adjustable output common-mode voltage via the VOCM pin.
• Features unique internal feedback for balanced output gain and phase matching, suppressing even-order harmonics.
• Delivers low harmonic distortion suitable for driving high-performance analog-to-digital converters.
• Supports externally adjustable gain and fast overload recovery to preserve sampling accuracy.

Applications

• ADC drivers
• Single-ended-to-differential converters
• IF and baseband gain blocks
• Differential buffers
• Line drivers

Procurement Notes

Verify the specific suffix 'AARZ-RL' against the manufacturer's official ordering guide to confirm package type (MSOP vs SOIC) and reel specifications. Ensure compatibility with the required operating temperature range of -40°C to +85°C. Cross-reference the datasheet revision history for any parameter updates that may affect design integration.

Selection Notes

Select this component when low harmonic distortion and high bandwidth are critical for signal integrity in data acquisition systems. The internal common-mode feedback simplifies layout by eliminating the need for matched external resistors for balance. Consider the 90 mW power dissipation for thermal management in compact designs.

Part Context

The AD8138 series represents a significant advancement over traditional op amps for differential signal processing. Manufactured on Analog Devices' proprietary XFCB bipolar process, it offers superior performance compared to discrete solutions or older integrated drivers. It eliminates the need for transformers in high-performance ADC applications, preserving low-frequency and DC information.

Replacement Considerations

Public confirmed substitute part numbers: AD8138ARZ, AD8138AARMZ.

FAQ

How does the AD8138 handle output common-mode voltage?

The output common-mode voltage is adjustable by applying a voltage to the VOCM pin. The internal common-mode feedback forces the output common-mode level to match the VOCM input voltage without affecting the differential output voltage.

What is the impact of external resistor mismatches on gain error?

The AD8138's internal feedback circuit minimizes gain errors associated with mismatches in external gain-setting resistors, ensuring balanced output gain and phase matching.