Low Noise, Rail-to-Rail,
Differential ADC Driver
AD8139
FEATURES
Fully differential
Low noise
2.25 nV/√Hz
2.1 pA/√Hz
Low harmonic distortion
98 dBc SFDR @ 1 MHz
85 dBc SFDR @ 5 MHz
72 dBc SFDR @ 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 @ 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
APPLICATIONS
ADC drivers to 18 bits
Single-ended-to-differential converters
Differential filters
Level shifters
Differential PCB drivers
Differential cable drivers
FUNCTIONAL BLOCK DIAGRAMS
–IN
1
V
OCM 2
V+
3
+OUT
4
AD8139
8
7
6
5
+IN
NC
V–
04679-001
–OUT
NC = NO CONNECT
Figure 1. 8-Lead SOIC
AD8139
TOP VIEW
(Not to Scale)
–IN 1
V
OCM
2
V+ 3
+OUT 4
NC = NO CONNECT
8 +IN
7 NC
6 V–
5 –OUT
04679-102
Figure 2. 8-Lead LFCSP
GENERAL DESCRIPTION
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
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 Analog Devices, Inc.
proprietary, 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.
100
INPUT VOLTAGE NOISE (nV/ Hz)
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
10M
100M
1G
Figure 3. Input Voltage Noise vs. Frequency
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2007 Analog Devices, Inc. All rights reserved.
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