LOG101

ACTIVE

Precision logarithmic and log ratio amplifier with scale factor of 1-V/decade

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NEW LOG200 PREVIEW High-speed precision logarithmic amplifier with photodiode bias and dark-current correction Upgraded performance and with integrated features. Smaller QFN package option.

Product details

Scale factor (V/decade) 1 Input current range (min) (nA) 100 Input current range (max) (mA) 3.5 Offset voltage (input amplifiers) (max) (mV) 1.5 Vs (±) (min) (V) 4.5 Vs (±) (max) (V) 18 Iq (max) (mA) 1.5 Dynamic range (typ) (dB) 150 Reference type External Auxiliary op amps 0 Full-scale output voltage (min) (±V) 1.2 Full-scale output voltage (max) (±V) 1.5 Conformity error (initial 5 decades) (max) (%) 0.2 Conformity error (initial 5 decades) (typ. over temp) (%/°C) 0.0001 Operating temperature range (°C) -40 to 85 Specified voltage (±V) 5 Rating Catalog
Scale factor (V/decade) 1 Input current range (min) (nA) 100 Input current range (max) (mA) 3.5 Offset voltage (input amplifiers) (max) (mV) 1.5 Vs (±) (min) (V) 4.5 Vs (±) (max) (V) 18 Iq (max) (mA) 1.5 Dynamic range (typ) (dB) 150 Reference type External Auxiliary op amps 0 Full-scale output voltage (min) (±V) 1.2 Full-scale output voltage (max) (±V) 1.5 Conformity error (initial 5 decades) (max) (%) 0.2 Conformity error (initial 5 decades) (typ. over temp) (%/°C) 0.0001 Operating temperature range (°C) -40 to 85 Specified voltage (±V) 5 Rating Catalog
SOIC (D) 8 29.4 mm² 4.9 x 6
  • EASY-TO-USE COMPLETE CORE FUNCTION
  • HIGH ACCURACY: 0.01% FSO Over 5 Decades
  • WIDE INPUT DYNAMIC RANGE:
         7.5 Decades, 100pA to 3.5mA
  • LOW QUIESCENT CURRENT: 1mA
  • WIDE SUPPLY RANGE: ±4.5V to ±18V
  • APPLICATIONS
    • LOG, LOG RATIO, ANTI-LOG COMPUTATION:
           Communication, Analytical, Medical, Industrial, Test, and General Instrumentation
    • PHOTODIODE SIGNAL COMPRESSION AMPS
    • ANALOG SIGNAL COMPRESSION IN FRONT OF ANALOG-TO-DIGITAL (A/D)CONVERTERS

Note: Protected under US Patent #6,667,650; other patents pending.

  • EASY-TO-USE COMPLETE CORE FUNCTION
  • HIGH ACCURACY: 0.01% FSO Over 5 Decades
  • WIDE INPUT DYNAMIC RANGE:
         7.5 Decades, 100pA to 3.5mA
  • LOW QUIESCENT CURRENT: 1mA
  • WIDE SUPPLY RANGE: ±4.5V to ±18V
  • APPLICATIONS
    • LOG, LOG RATIO, ANTI-LOG COMPUTATION:
           Communication, Analytical, Medical, Industrial, Test, and General Instrumentation
    • PHOTODIODE SIGNAL COMPRESSION AMPS
    • ANALOG SIGNAL COMPRESSION IN FRONT OF ANALOG-TO-DIGITAL (A/D)CONVERTERS

Note: Protected under US Patent #6,667,650; other patents pending.

The LOG101 is a versatile integrated circuit that computes 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 come 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.

The LOG101 is a versatile integrated circuit that computes 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 come 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.

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* Data sheet LOG101: Precision Logarithmic and Log Ratio Amplifier datasheet (Rev. B) 10 Jun 2004

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Simulation model

LOG101 PSpice Model (Rev. B)

SBOC042B.ZIP (24 KB) - PSpice Model
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PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
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TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
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