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
µA741 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/µs, 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 25µV
• 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
2
3
4
8
7
6
5
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 8-Pin 8-Pin
Small Outline Plastic Dip CERDIP
Package (SOIC) Package 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))
e
EPAD
TM
®
N
A
B
L
E
D
E
PRECISION LOW POWER CMOS OPERATIONAL AMPLIFIER
ALD1722/ALD1722G
A
DVANCED
L
INEAR
D
EVICES,
I
NC.
