ADI ADA4350ARUZ-R7

The ADA4350 is an analog front end for photodetectors or other sensors whose output produces a current proportional to the sensed parameter or voltage input applications where the system requires the user to select between very precise gain levels to maximize the dynamic range. The ADA4350 integrates a FET input amplifier, a switching network, and an ADC driver with all functions controllable via a serial peripheral interface (SPI) or parallel control logic into a single IC. The FET input amplifier has very low voltage noise and current noise making it an excellent choice to work with a wide range of photodetectors, sensors, or precision data acquisition systems. Its switching network allows the user individual selection of up to six different, externally configurable feedback networks; by using external components for the feedback network, the user can more easily match the system to their desired photodetector or sensor capacitance. This feature also allows the use of low thermal drift resistors, if required. The design of the switches minimizes error sources so that they add virtually no error in the signal path. The output driver can be used in either single-ended or a differential mode and is ideal 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 of the detector. It is available in a Pb-free, 28-lead TSSOP package and is specified to operate over the -40°C to +85°C temperature range.

• Low noise, low input bias current FET input amplifier
• Very low input bias current: ±0.25 pA typical at 25°C
• Low input voltage noise 92 nV/√Hz typical at 10 Hz at 5 V
• 5 nV/√Hz typical at 100 kHz at ±v
• Gain bandwidth product: 175 MHz
• Input capacitance 3 pF typical, differential mode
• 2 pF typical, common mode
• Integrated gain switching
• Sampling and feedback switch off leakage: ±0.5 pA typical
• Worst case tON/tOFF times: 105 ns typical/65 ns typical
• Integrated analog-to-digital converter (ADC) driver
• Differential mode and single-ended mode
• Adjustable output common-mode voltage −5 V to +3.8 V typical for ±v supply
• Wide output voltage swing: ±4.8 V minimum for ±5 V supply
• Linear output current: 1 m rms typical for ±5 V supply
• SPI or parallel switch control of all functions
• Wide operating range: 3.3 V to 12 V
• Quiescent current: 8.5 mA typical (±5 V full system)

• Current to voltage (I to V) conversions
• Photodiode preamplifiers
• Chemical analyzers
• Mass spectrometry
• Molecular spectroscopy
• Laser/LED receivers
• Data acquisition systems