ADA4937-1_07 Datasheet, PDF (1/28 Pages) Analog Devices – Ultralow Distortion, Differential ADC Driver

FEATURES
Extremely low harmonic distortion
−112 dBc HD2 @ 10 MHz
−79 dBc HD2 @ 70 MHz
−70 dBc HD2 @ 100 MHz
−102 dBc HD3 @ 10 MHz
−91 dBc HD3 @ 70 MHz
−84 dBc HD3 @ 100 MHz
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%
0.1 dB gain flatness to 200 MHz
Fast overdrive recovery of 1 ns
1 mV typical offset voltage
Externally adjustable gain
Differential-to-differential or single-ended-to-differential
operation
Adjustable output common-mode voltage
Single-supply operation: 3.3 V to 5 V
Pb-free, 3 mm × 3 mm 16-lead LFCSP
APPLICATIONS
ADC drivers
Single-ended-to-differential converters
IF and baseband gain blocks
Differential buffers
Line drivers
GENERAL DESCRIPTION
The ADA4937-1 is a low noise, ultralow distortion, high speed
differential amplifier. It is 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 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.
With the ADA4937-1, differential gain configurations are easily
realized with a simple external feedback network of four
resistors determining the closed-loop gain of the amplifier.
Ultralow Distortion,
Differential ADC Driver
ADA4937-1
FUNCTIONAL BLOCK DIAGRAM
–FB 1
+IN 2
–IN 3
+FB 4
ADA4937-1
12 PD
11 –OUT
10 +OUT
9 V_OCM
Figure 1.
–55
–60
–65
–70
–75
–80
–85
–90
–95
–100
–105
–110
–115
1
HD2, V_S = 5.0V
HD3, V_S = 5.0V
HD2, V_S = 3.3V
HD3, V_S = 3.3V
10
100
FREQUENCY (MHz)
Figure 2. Harmonic Distortion vs. Frequency
The ADA4937-1 is fabricated using Analog Devices, Inc.
proprietary silicon-germanium (SiGe), complementary bipolar
process, enabling it 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 make it
well suited for a wide variety of data acquisition and signal
processing applications.
The ADA4937-1 is available in a Pb-free, 3 mm × 3 mm 16-lead
LFCSP. The pinout has been optimized to facilitate PCB layout
and minimize distortion. The part is specified to operate over
the −40°C to +105°C temperature range for 3.3 V supplies and
the −40°C to +85°C temperature range for 5 V supplies.
Rev. 0
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