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 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 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

mA741 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/ms, 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 conditions.

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 25mV

• 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