Ultralow Distortion
Differential ADC Driver
ADA4937-1/ADA4937-2
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
ADA4937-1
Extremely low harmonic distortion (HD)
−112 dBc HD2 at 10 MHz
−84 dBc HD2 at 70 MHz
−77 dBc HD2 at 100 MHz
−102 dBc HD3 at 10 MHz
−91 dBc HD3 at 70 MHz
−84 dBc HD3 at 100 MHz
–FB
+IN
1
2
3
4
12
PD
11 –OUT
10
9
–IN
+OUT
+FB
V
OCM
Low input voltage noise: 2.2 nV/√Hz
High speed
−3 dB bandwidth of 1.9 GHz, G = 1
Slew rate: 6000 V/μs, 25% to 75%
Fast overdrive recovery of 1 ns
0.5 mV typical offset voltage
Externally adjustable gain
Figure 1. ADA4937-1
ADA4937-2
Differential-to-differential or single-ended-to-differential
operation
Adjustable output common-mode voltage
Single-supply operation: 3.3 V to 5 V
1
2
3
4
5
6
18
17
16
15
14
–IN1
+OUT1
+FB1
V
OCM1
–V
–V
+V
S1
S2
S2
+V
S1
–FB2
+IN2
PD2
APPLICATIONS
13 –OUT2
ADC drivers
Single-ended-to-differential converters
IF and baseband gain blocks
Differential buffers
Figure 2. ADA4937-2
–55
–60
Line drivers
HD2, V = 5.0V
S
HD3, V = 5.0V
S
GENERAL DESCRIPTION
HD2, V = 3.3V
S
–65
HD3, V = 3.3V
S
The ADA4937-1/ADA4937-2 are low noise, ultralow distortion,
high speed differential amplifiers. They are an ideal choice for
driving high performance ADCs with resolutions up to 16 bits
from dc to 100 MHz. The adjustable level of the output common
mode allows the ADA4937-1/ADA4937-2 to match the input
of the ADC. The internal common-mode feedback loop also
provides exceptional output balance as well as suppression of
even-order harmonic distortion products.
–70
–75
–80
–85
–90
–95
–100
–105
–110
–115
With the ADA4937-1/ADA4937-2, differential gain configurations
are easily realized with a simple external feedback network of
four resistors that determine the closed-loop gain of the amplifier.
1
10
FREQUENCY (MHz)
100
Figure 3. Harmonic Distortion vs. Frequency
The ADA4937-1/ADA4937-2 are fabricated using Analog Devices,
Inc., proprietary silicon-germanium (SiGe), complementary
bipolar process, enabling them to achieve very low levels of
distortion with an input voltage noise of only 2.2 nV/√Hz.
The low dc offset and excellent dynamic performance of the
ADA4937-1/ADA4937-2 make them well-suited for a wide
variety of data acquisition and signal processing applications.
The ADA4937-1/ADA4937-2 are available in a Pb-free, 3 mm ×
3 mm, 16-lead LFCSP (ADA4937-1, single) or a Pb-free, 4 mm ×
4 mm, 24-lead LFCSP (ADA4937-2, dual). The pinout has been
optimized to facilitate PCB layout and minimize distortion.
The ADA4937-1/ADA4937-2 are specified to operate over the
automotive (−40°C to +105°C) temperature range and between
3.3 V and 5 V supplies.
Rev. F
Document Feedback
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2007–2016 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com