Description

The ADA4350 is an analog front end for photodetectors or othersensors whose output produces a current proportional to thesensed parameter or voltage input applications where the systemrequires the user to select between very precise gain levels tomaximize the dynamic range.The ADA4350 integrates a FET input amplifier, a switching network,and an ADC driver with all functions controllable via a serialperipheral interface (SPI) or parallel control logic into a singleIC. The FET input amplifier has very low voltage noise and currentnoise making it an excellent choice to work with a wide range ofphotodetectors, sensors, or precision data acquisition systems.Its switching network allows the user individual selection of upto six different, externally configurable feedback networks; byusing external components for the feedback network, the usercan more easily match the system to their desired photodetector orsensor capacitance. This feature also allows the use of low thermaldrift resistors, if required.The design of the switches minimizes error sources so that theyadd virtually no error in the signal path. The output driver canbe used in either single-ended or a differential mode and isideal for driving the input of an ADC.The ADA4350 can operate from a single +3.3 V supply or a dual±5 V supply, offering user flexibility when choosing the polarity ofthe detector. It is available in a Pb-free, 28-lead TSSOP package andis specified to operate over the −40°C to +85°C temperature range.Multifunction pin names may be referenced by their relevantfunction only.Applications Current to voltage (I to V) conversions Photodiode preamplifiers Chemical analyzers Mass spectrometry Molecular spectroscopy Laser/LED receivers Data acquisition systems