Economy, Wideband Log/Antilog Amplifiers Models 759N, 759P FEATURES Low-Cost, Complete Log/Antilog Amplifier External Components Not Required; Internal Reference; Temperature Compensated Small Size: 1.1" x 1.1" x 0.4" Fast Response: 200kHz Bandwidth (ISIG @ 1µA) 6 Decades Current Operation - 1nA to 1mA 1% max Error - 20nA to 200µA 2% max Error - 10nA to 1mA 4 Decades Voltages Operation - 1 mV to 10V 1% max Error - 1mV to 2V 2% max Error - 1mV to 10V APPLICATIONS Log Current or Voltage Antilog Voltage Data Compression or Expansion GENERAL DESCRIPTION Models 759N and 759P are low cost, fast response, dc logarithmic amplifiers offering 1% conformance to ideal log operation over four decades of current operation - 20nA to 200µA, as well as 2% conformance over four decades of voltage operation - 1mV to 10V. Featuring 200kHz bandwidth at ISIG = 1µA, these new economy designs are the industry’s fastest log/antilog amplifiers and offer an attractive alternative to in-house designs. measurements, data compression and expansion, chemical analysis of liquids, computing powers, roots and ratios and conversion of exponential quantities to linear form. Designed for ease of use, models 759N/P are complete, temperature compensated, log or antilog amplifiers packaged in a small 1.1" x 1.1" x 0.4" epoxy encapsulated module. External components are not required for logging currents over the complete six decade operating range from 1nA to 1mA. Both the scale factor (K = 2, 1, 2/3 volt/decade) and log/antilog operation can be selected by simple pin interconnection. In addition both the internal 10µA reference current as well as the offset voltage may be externally adjusted to improve overall accuracy performance. MODEL SELECTION Model 759N computes the log of positive input signals (voltage or current), while model 759P computes the log of negative input signals (voltage or current). In the antilog mode of operation, both models accept bipolar voltage input signals (-2V≤ESIG/ K≤-2V), with model 759N producing a positive output signal and model 759P producing a negative output signal. APPLICATIONS Model 759N and 759P can operate with either current or voltage inputs when connected as shown in Figure 1. To illustrate the logarithmic transfer characteristics, a plot of input current versus output voltage is also presented. Model 759 is ideally suited for log applications whenever low cost implementation of logarithmic natural relationships is advantages. Examples are absorbence Information furnished by Intronics is believed to be accurate and reliable. However, no responsibility is assumed by Intronics for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intronics. Figure1. Functional Block Diagram and Transfer Function 1400 Providence Highway, Building #2 Norwood, MA 02062 Phone (781) 551-5500 FAX (781) 551-5555 www.intronicspower.com