Low Noise, Rail-to-Rail, Differential ADC Driver

The AD8139 is an ultralow noise, high performance differential amplifier with rail-to-rail output. With its low noise, high SFDR, and wide bandwidth, it is an ideal choice for driving analog-to-digital converters (ADCs) with resolutions to 18 bits. The AD8139 is easy to apply, and its internal common-mode feedback architecture allows its output common-mode voltage to be controlled by the voltage applied to one pin. The internal feedback loop also provides outstanding output balance as well as suppression of even-order harmonic distortion products. Fully differential and single-ended-to-differential gain configurations are easily realized by the AD8139. Simple external feedback networks consisting of four resistors determine the closed-loop gain of the amplifier.

The AD8139 is manufactured on the proprietary Analog Devices, Inc., second-generation XFCB process, enabling it to achieve low levels of distortion with input voltage noise of only 2.25 nV/√Hz.

The AD8139 is available in an 8-lead SOIC package with an exposed paddle (EP) on the underside of its body and a 3 mm × 3 mm LFCSP. It is rated to operate over the temperature range of −40°C to +125°C.

Applications

* ADC drivers to 18 bits

* Single-ended-to-differential converters

* Differential filters

* Level shifters

* Differential PCB drivers

* Differential cable drivers

* Fully differential

* Low noise

* 2.25 nV/√Hz

* 2.1 pA/√Hz

* Low harmonic distortion

* 98 dBc SFDR at 1 MHz

* 85 dBc SFDR at 5 MHz

* 72 dBc SFDR at 20 MHz

* High speed

* 410 MHz, 3 dB BW (G = 1)

* 800 V/µs slew rate

* 45 ns settling time to 0.01%

* 69 dB output balance at 1 MHz

* 80 dB dc CMRR

* Low offset: ±0.5 mV maximum

* Low input offset current: 0.5 µA maximum

* Differential input and output

* Differential-to-differential or single-ended-to-differential operation

* Rail-to-rail output

* Adjustable output common-mode voltage

* Wide supply voltage range: 5 V to 12 V

* Available in a small SOIC package and an 8-lead LFCSP