LOG101 Datasheet | Burr-Brown

FEATURES q EASY-TO-USE PLETE CORE FUNCTION q HIGH ACCURACY: 0.01% FSO Over 5 Decades q WIDE INPUT DYNAMIC RANGE: 7.5 Decades, 100p A to 3.5m A q LOW QUIESCENT CURRENT: 1m A q WIDE SUPPLY RANGE: ±4.5V to ±18V DESCRIPTION The LOG101 is a versatile integrated circuit that putes the logarithm or log ratio of an input current relative to a reference current. The LOG101 is tested over a wide dynamic range of input signals. In log ratio applications, a signal current can e from a photodiode, and a reference current from a resistor in series with a precision external reference. The output signal at VOUT is trimmed to 1V per decade of input current allowing seven decades of input current dynamic range. Low DC offset voltage and temperature drift allow accurate measurement of low-level signals over a wide environmental temperature range. The LOG101 is specified over the temperature range - 5° C to +75 ° C, with operation over - 40°C to +85°C. Note: Protected under US Patent #6,667,650; other patents pending. APPLICATIONS q LOG, LOG RATIO PUTATION: munication, Analytical, Medical, Industrial, Test, and General Instrumentation q PHOTODIODE SIGNAL PRESSION AMPS q ANALOG SIGNAL PRESSION IN FRONT OF ANALOG-TO-DIGITAL (A/D) CONVERTERS I2 V+ 4 I1 1 VOUT = (1V) - LOG (I1/I2) 8 LOG101 Q1 Q2 A1 A2 R2 VOUT R1 5 GND V- 6 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2002-2004, Texas Instruments Incorporated .ti. ABSOLUTE MAXIMUM RATINGS(1) Supply Voltage, V+ to V-...