GENERAL DESCRIPTION
The ALD1721/ALD1721G is a monolithic CMOS micropower high slew
rate 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
minimum 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 translates into a significant distortion or "interface noise equivalent"
term.
The ALD1721/ALD1721G is designed to set a new standard in low input
signal power requirements. The typical input loading at its input is 0.05 mV
offset voltage and 0.01 pA input bias current at 25C, resulting in 0.0005
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 ALD1721/
ALD1721G is ideally suited. It is readily suited for +5V single supply (or
±1V to ±5V) systems, with low operating power dissipation, a traditional
strength of CMOS technology. It is offered with industry standard pin
configuration of mA741 and ICL7611 types.
The ALD1721/ALD1721G 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. In addition, the device can
accommodate mixed applications where digital and analog circuits may
operate off the same power supply or battery. Finally, the output stage
can typically drive up to 50pF capacitive and 10KW resistive loads.
These features make the ALD1721/ALD1721G a versatile, micropower
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 conditions.

FEATURES & BENEFITS
• Lead Free - RoHS compatible
• Robust high-temperature operation
• Guaranteed extremely low input signal
power of 1.5 fW
• Input offset voltage of 0.05 mV typical
(0.15 mV max.)
• Low input bias currents of 0.01pA typical
(10pA max.)
• Rail to rail input and output voltage ranges
• All parameters specified for +5V single
supply or ±2.5V dual supplies
• Unity gain stable, no compensation needed
• High voltage gain -- typically 100V/mV @
±2.5V(100dB)
• Drive as low as 10KW load
• Output short circuit protected
• Unity gain bandwidth of 0.7MHz
• Slew rate of 0.7V/ms
• Micro power dissipation
• Suitable for rugged, temperature-extreme
environments

APPLICATIONS
• Voltage amplifier
• Voltage follower/buffer
• Charge integrator
• Photodiode amplifier
• Data acquisition systems
• High performance portable instruments
• Signal conditioning circuits
• Sensor and transducer amplifiers
• Low leakage amplifiers
• Active filters
• Sample/Hold amplifier
• Picoammeter
• Current to voltage converter