Low Power, 3.6 MHz, Low Noise, Rail-to-
Rail Output, Operational Amplifiers
ADA4691-2/ADA4691-4/ADA4692-2/ADA4692-4
Rev. D
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 ©2009–2010 Analog Devices, Inc. All rights reserved.
FEATURES
Low power: 180 μA typical
Very low input bias currents: 0.5 pA typical
Low noise: 16 nV/√Hz typical
3.6 MHz bandwidth
Offset voltage: 500 μV typical
Low offset voltage drift: 4 μV/°C maximum
Low distortion: 0.003% THD + N
2.7 V to 5 V single supply or ±1.35 V to ±2.5 V dual supply
Available in very small 2 mm × 2 mm LFCSP packages
APPLICATIONS
Photodiode amplifiers
Sensor amplifiers
Portable medical and instrumentation
Portable audio: MP3s, PDAs, and smartphones
Communications
Low-side current sense
ADC drivers
Active filters
Sample-and-hold
GENERAL DESCRIPTION
The ADA4691-2/ADA4692-2 are dual and the ADA4691-4/
ADA4692-4 are the quad rail-to-rail output, single-supply
amplifiers featuring low power, wide bandwidth, and low noise.
The ADA4691-2 has two independent shutdown pins, allowing
further reduction in supply current. The ADA4691-4 is a quad
with dual shutdown pins each controlling a pair of amplifiers
and is available in the 16-lead LFCSP. The ADA4692-4 is a quad
version without shutdown.
These amplifiers are ideal for a wide variety of applications.
Audio, filters, photodiode amplifiers, and charge amplifiers, all
benefit from this combination of performance and features.
Additional applications for these amplifiers include portable
consumer audio players with low noise and low distortion that
provide high gain and slew rate response over the audio band at
low power. Industrial applications with high impedance sensors,
such as pyroelectric and IR sensors, benefit from the high
impedance and low 0.5 pA input bias, low offset drift, and
enough bandwidth and response for low gain applications.
The ADA4691/ADA4692 family is fully specified over the extended
industrial temperature range (−40°C to +125°C). e ADA4691-2
is available in a 10-lead LFCSP and a 9-ball WLCSP. The ADA4692-2
is available in an 8-lead SOIC and 8-lead LFCSP. The ADA4691-4 is
available in a 16-lead LFCSP. The ADA4692-4 is available in a 14-lead
TSSOP. For pin configurations, see the Pin Configurations section.
1
0.1
0.01
0.00110 100 1k 10k 20k
THD + N (%)
FREQUENCY ( Hz)
ADA4692-2
V
SY
= ±2.5V
A
V
= –1
T
A
= 25°C
07950-142
R
L
= 600Ω
R
L
= 2kΩ
Figure 1. THD + Noise vs. Frequency
80
–90
–100
–110
–120
–130
–140
100 1k 10k 100k
CHANNEL SEPARAT ION ( dB)
FREQUENCY (Hz)
07950-141
ADA4692-2
V
SY
= ±2.5V
V
IN
= 2. 8V p - p
A
V
= +1
T
A
= 25°C
Figure 2. Channel Separation vs. Frequency
Table 1.
Micropower Low Power Low Power with Shutdown Standard Op Amp With Shutdown High Bandwidth
Single AD8613 AD8591 AD8691
Dual AD8617 ADA4692-2 ADA4691-2 AD8592 AD8692
Quad AD8619 ADA4692-4 ADA4691-4 AD8594 AD8694