Rev 2.1 2011 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286
www.aldinc.com
GENERAL DESCRIPTION
The ALD1722/ALD1722G is a monolithic precision low power CMOS
operational amplifier intended for a broad range of precision applications
requiring exremely low input signal power. Input signal power is the product
of input offset voltage and input bias current, which represents the mini-
mum required power draw from the signal source in order to drive the input
of the operational amplifier. Input signal power is also a figure of merit in
source loading and its associated error, and is a measure of the basic signal
resolution possible through the operational amplifier for a given signal
source. For certain types of signal sources, signal loading directly trans-
lates into a significant distortion or "interface noise equivalent " term.
The ALD1722/ALD1722G is designed to set a new standard in low input
signal power requirements. The typical input loading at its input is 0.03 mV
offset voltage and 0.01 pA input bias current at 25C, resulting in 0.0003 fW
input signal power draw. This input characteristic virtually eliminates any
loading effects on most types of signal sources, offering unparalled
accuracy and signal integrity and fidelity. Obviously, for capacitive and high
sensitivity, high impedance signal sources, the ALD1722/ALD1722G is
ideally suited. It is readily suited for +5V single supply (or
±2V to ±5V)
systems, with low operating power dissipation, a traditional strength of
CMOS technology. It is offered with industry standard pin configuration of
A741 and ICL7611 types.
The ALD1722/ALD1722G can operate with rail to rail large signal input and
output voltages with relatively high slew rate. The input voltage can be
equal to or exceed the positive and negative supply voltages while the
output voltage can swing close to these supply voltage rails. This feature
significantly reduces the supply overhead voltage required to operate the
operational amplifier and allows numerous analog serial stages to operate
in a low power supply environment. circuits may operate off the same power
supply or battery. This device also features rail-to-rail input and output
voltage ranges, tolerance to over-voltage input spikes of 300mV beyond
supply rails, high open loop voltage gain, useful bandwidth of 1.5 MHz, slew
rate of 2.1 V/
s, and low supply current of 0.8mA. Finally, the output stage
can typically drive up to 400pF capacitive loads in the unity gain mode and
up to 4000 pF capacitive load at a gain of 5.
These features make the ALD1722/ALD1722G a versatile, high precision
operational amplifier that is user friendly and easy to use with virtually no
source loading and zero input-loading induced source errors. Additionally,
robust design and rigorous screening make this device especially suitable
for operation in temperature-extreme environments and rugged condi-
tions.
FEATURES & BENEFITS
Lead Free - RoHS compatible
Robust high-temperature operation
Industry standard pinout
Rail-to-rail input/output
Exremely low input signal power
Input bias current of 0.01pA and
input offset voltage of 25
V
No external components
No internal chopper clocking noise
No chopper dynamic power dissipation
Simple and cost effective
Small package size
Drive up to 4000pF load capacitance
Low power
Suitable for rugged, temperature-extreme
environments
APPLICATIONS
Precision cable driver
Sensor interface circuits
Unity gain buffer amplifier
Precision analog cable driver
Transducer biasing circuits
Capacitive and charge integration circuits
Biochemical probe interface
Signal conditioning
Portable instruments
High source impedance electrode
amplifiers
Precision Sample and Hold amplifiers
Precision current to voltage converter
Error correction circuits
Sensor compensation circuits
Precision gain amplifiers
System output level shifter
PIN CONFIGURATION
* N/C pins are internally connected. Do not connect externally.
1
2
3
4
8
7
6
5
TOP VIEW
N/C
-IN
+IN
N/C
OUT
N/C
V-
V+
TOP VIEW
SAL, PAL, DA PACKAGES
Operating Temperature Range
0
°C to +70°C0°C to +70°C
-55
°C to +125°C
8-Pin
Small Outline
Plastic Dip
CERDIP
Package (SOIC)
Package
ALD1722SAL
ALD1722PAL
ALD1722DA
ALD1722GSAL
ALD1722GPAL
ALD1722GDA
* Contact factory for leaded (non-RoHS) or high temperature versions.
ORDERING INFORMATION (“L” suffix denotes lead-free (RoHS))
eEPAD
TM
N
A
B
L
E
D
E
PRECISION LOW POWER CMOS OPERATIONAL AMPLIFIER
ALD1722/ALD1722G
ADVANCED
LINEAR
DEVICES, INC.