GENERAL DESCRIPTION

The ALD1722E is a monolithic rail-to-rail precision CMOS operational amplifier with integrated user programmable EPAD (Electrically Programmable Analog Device) based offset voltage adjustment. The ALD1722E is a direct replacement of the ALD1712 operational amplifier, with the added feature of user-programmable offset voltage trimming resulting in significantly enhanced total system performance and user flexibility. EPAD technology is an exclusive ALD design which has been refined for analog applications where precision voltage trimming is necessary to achieve a desired performance. It utilizes CMOS FETs as in-circuit elements for trimming of offset voltage bias characteristics with the aid of a personal computer under software control. Once programmed, the set parameters are stored indefinitely within the device even after power down. EPAD offers the circuit designer a convenient and cost-effective trimming solution for achieving the very highest amplifier/system performance.

The ALD1722E operational amplifier features rail-to-rail input and output voltage ranges, tolerance to over-voltage input spikes of 300mV beyond supply rails, high capacitive loading up to 4000pF, extremely low input currents of 0.01pA typical, high open loop voltage gain, useful bandwidth of 1.5MHz, slew rate of 2.1V/µs, and low supply current of 0.8mA.

KEY FEATURES

• EPAD (Electrically Programmable Analog Device)

• User programmable VOS trimmer

• Computer-assisted trimming

• Rail-to-rail input/output

• Compatible with standard EPAD Programmer

• High precision through in-system circuit precision trimming

• Reduces or eliminates VOS, PSRR, CMRR and TCVOS errors

• System level “calibration” capability

• Application Specific Programming mode

• In-System Programming mode

• Electrically programmable to compensate for external component tolerances

• Achieves 0.01pA input bias current and 25µV input offset voltage simultaneously

• Compatible with industry standard pinout

APPLICATIONS

• 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

• Current sources

• Periodic In-system calibration

• System output level shifter