Precise Electrometer-Grade Amplifier Tweaks Chemical Analysis Instruments

Analog Devices instigates an electrometer-grade operational amplifier that enables chemical analysis instruments to achieve the highest level of precision and data repeatability over a wider temperature range in a compact solution mitigating overall bill of materials and design footprint.

• The ADA4530-1 op amp, with an input bias current that is at least 20 times lower than competing devices making it ideal for interfacing to sensors that are sensitive to output loading such as photo diodes and other high output impedance sensors often used in precision monitoring/analysis equipment such as spectrophotometers, chromatographs and mass spectrometers, as well as potentiostatic and amperostatic coulometry measurement devices.
• The new amp also can be used as a front-end amplifier for picoammeter and coulombmeter instrumentation systems, as a transimpedance amplifier for photodiodes, ion chambers, and working electrode measurements, or as a high-impedance buffer for chemical and capacitive sensors.

Key Features

Ultra-low bias current

• 20 fA @ 25°C max (Production Tested)
• 20 fA @ 85°C max
• 250 fA @ 125°C max (Production Tested)

Integrated guard buffer

Wide supply voltage: ±2.5 to ±8 V or 5 to 16 V

The ADA4530-1 also incorporates an on-chip guard buffer that tracks the input common-mode voltage and provides an output that is useful for driving PCB guard rings or the guard shield of interconnecting shielding used to reduce the effects of stray capacitance on the sensitive connections between the sensor and the amplifier.

Pricing and Availability