Precision HighSpeed Logarithmic Amplifier With 2.5V Reference And Uncommitted Output Op AmpsThe LOG114 is specifically designed for measuring lowlevel and wide dynamic range currents in Communications lasers, medical, and industrial systems. The device computes the logarithm or logratio of an input current or voltage relative to a reference current or voltage (logarithmic transimpedance amplifier).
High precision is ensured over a wide dynamic range of input signals on either bipolar (5V) or single (+5V) supply. Special temperature drift compensation circuitry is included onchip. In logratio applications, the signal current may be from a high impedance source such as a Photodiode or resistor in series with a low impedance voltage source. The reference current is provided by a resistor in series with a precision internal Voltage Reference photo Diode or active current source.
The output signal at VLOGOUT has a scale factor of 0.375V out per decade of input current, which limits the output so that it fits within a 5V or 10V range. The output CAN be scaled and offset with one of the available additional Amplifiers so it matches a wide variety of ADC input ranges. Stable dc performance allows accurate measurement of lowlevel signals over a wide temperature range. The LOG114 is specified over a 5C to +75C temperature range and CAN operate from 40C to +85C. By Texas Instruments

Part  Manufacturer  Description  Datasheet  Samples  

LOG114AIRGVRG4  Texas Instruments  Precision HighSpeed Logarithmic Amplifier with 2.5V Reference and Uncommitted Output Op Amps 16VQFN 0 to 70  
LOG114AIRGVTG4  Texas Instruments  Precision HighSpeed Logarithmic Amplifier with 2.5V Reference and Uncommitted Output Op Amps 16VQFN 0 to 70  
LOG114AIRGVT  Texas Instruments  Precision HighSpeed Logarithmic Amplifier with 2.5V Reference and Uncommitted Output Op Amps 16VQFN 0 to 70  
LOG114AIRGVR  Texas Instruments  Precision HighSpeed Logarithmic Amplifier with 2.5V Reference and Uncommitted Output Op Amps 16VQFN 0 to 70 

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