Datasheet AD8021 (Analog Devices)

Low Noise, High Speed Amplifier for 16-Bit Systems AD8021 FEATURES CONNECTION DIAGRAM Low noise LOGIC AD8021 2.1 nV/√Hz input voltage noise 1 8 REFERENCE DISABLE 2.1 pA/√Hz input current noise –IN 2 7 +VS Custom compensation +IN 3 6 VOUT Constant bandwidth from G = −1 to G = −10 –VS 4 5 CCOMP High speed
01888-001
200 MHz (G = −1)
Figure 1. SOIC-8 (R-8) and MSOP-8 (RM-8)
190 MHz (G = −10) Low power 34 mW or 6.7 mA typical for 5 V supply
The AD8021 allows the user to choose the gain bandwidth
Output disable feature, 1.3 mA
product that best suits the application. With a single capacitor,
Low distortion
the user can compensate the AD8021 for the desired gain with
−93 dBc second harmonic, fC = 1 MHz
little trade-off in bandwidth. The AD8021 is a well-behaved
−108 dBc third harmonic, fC = 1 MHz
amplifier that settles to 0.01% in 23 ns for a 1 V step. It has a fast
DC precision
overload recovery of 50 ns.
1 mV maximum input offset voltage 0.5 μV/°C input offset voltage drift
The AD8021 is stable over temperature with low input offset
Wide supply range, 5 V to 24 V
voltage drift and input bias current drift, 0.5 μV/°C and 10 nA/°C,
Low price
respectively. The AD8021 is also capable of driving a 75 Ω line
Small packaging
with ±3 V video signals.
Available in SOIC-8 and MSOP-8
The AD8021 is both technically superior and priced considerably less than comparable amps drawing much higher quiescent
APPLICATIONS
current. The AD8021 is a high speed, general-purpose amplifier,
ADC preamps and drivers
ideal for a wide variety of gain configurations and can be used
Instrumentation preamps
throughout a signal processing chain and in control loops. The
Active filters
AD8021 is available in both standard 8-lead SOIC and MSOP
Portable instrumentation
packages in the industrial temperature range of −40°C to +85°C.
Line receivers Precision instruments Ultrasound signal processing 24 V High gain circuits OUT = 50mV p-p 21 G = –10, R 18 F = 1k
Ω
, RG = 100
Ω
, GENERAL DESCRIPTION RIN = 100
Ω
, CC = 0pF 15
The AD8021 is an exceptionally high performance, high speed
G = –5, R 12 F = 1k
Ω
, RG = 200
Ω
, R
voltage feedback amplifier that can be used in 16-bit resolution
IN = 66.5
Ω
, CC = 1.5pF 9
systems. It is designed to have both low voltage and low current
6
noise (2.1 nV/√Hz typical and 2.1 pA/√Hz typical) while operating
G = –2, RF = 499
Ω
, RG = 249
Ω
,
at the lowest quiescent supply current (7 mA @ ±5 V) among
3 RIN = 63.4
Ω
, CC = 4pF CLOSED-LOOP GAIN (dB)
today’s high speed, low noise op amps. The AD8021 operates
0 G = –1, R
over a wide range of supply voltages from ±2.25 V to ±12 V, as
F = 499
Ω
, RG = 499
Ω
, –3 RIN = 56.2
Ω
, CC = 7pF
well as from single 5 V supplies, making it ideal for high speed,
–6
01888-002 low power instruments. An output disable pin allows further
0.1M 1M 10M 100M 1G FREQUENCY (Hz)
reduction of the quiescent supply current to 1.3 mA. Figure 2. Small Signal Frequency Response
Rev. F 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. 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. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION CONNECTION DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS MAXIMUM POWER DISSIPATION ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TEST CIRCUITS APPLICATIONS USING THE DISABLE FEATURE THEORY OF OPERATION PCB LAYOUT CONSIDERATIONS DRIVING 16-BIT ADCs DIFFERENTIAL DRIVER USING THE AD8021 IN ACTIVE FILTERS DRIVING CAPACITIVE LOADS OUTLINE DIMENSIONS ORDERING GUIDE