Log ratio Amplifier has six decade dynamic range:  11/27/03 EDN Design Ideas  / (added 2/06)   You need optical-power monitoring to guarantee overall system performance in fiber-optic communication systems. Logarithmic-signal processing can maintain precise measurements over a wide dynamic range. The wide-dynamic-range signal undergoes compression, and the use of a lower resolution measurement system then saves cost.

Logarithmic Amplifier:  Logarithmic amplifier uses the log caracteristic of PN (diode, transistor) to implement logarithmic function. The second transistor is used as refference and with the PTK resistor minimizes the dT/dV coeficient. / (Electronic Circuit diagram added 03/03)

LX1741/1742 Formula Calculator for AN22:  MicroNote 1310 from Microsem  (Circuit / schematic design added 6/06)

Math Utility Routines:  Microchip Application Note - Published 26-Aug-97   (added 2/06)

MathCAD functions perform log interpolation:  10/30/03 EDN Design Ideas  /  (Electronic circuit design added 02/05)  MathCAD provides a number of interpolation and curve-fitting functions, so that, given a set of X-Y data points, you can estimate the Y value for any given X coordinate. Unfortunately, these functions work poorly with data that is to be displayed in a nonlinear (logarithmic) manner. Examples of these functions are: Using the built-in "linterp" function, MathCAD estimates and plots the data (Fig......

Mixed signal algorithm tests transducers:  04/24/97 EDN-Design Ideas  / (added 2/06) 

Model Fixed Point DSP Arithmetic in C:  03/18/99 EDN-Design Ideas / (Circuit / schematic design added 6/06) You can run initial high-level simulations of custom numerical algorithms, such as digital filters, using floating-point numbers in an environment such as C or Matlab. Unfortunately, you won't see include fixed-point effects, such as truncation due to limited precision and register overflow, until you use a Hardware Design Language (HDL), such as Verilog or VHDL. However, a technique that models these effects in C—the function "bit_limit" in Listing 1—provides faster execution and better portability than HDLs and allows early exploration of the trade-off between bus width and performance.

Motor drive algorithm saves space and cycles:  02/17/94 EDN Design Ideas / (added 2/06)

Numerical Integration Techniques (TC7109):  Microchip Application Note - Published 12-Nov-02   (added 2/06)

PIC16c5x/PIC16cxx Utility Math Routines:  Microchip Application Note - Published 26-Aug-97   (Circuit / schematic design added 6/06)

Primer on Binary Arithmetic Rounding:  01/21/99 EDN-Design Ideas  / (added 2/06)   As digital communications and data compression/decompression proliferate, signal-processing functions grow in importance. Whether you’re dealing with hard-wired logic or programmable engines, an understanding of binary-arithmetic rounding is important in getting correct and consistent results. Before we discuss rounding, consider a binary number (Figure 1). At first glance, rounding seems a simple matter. However, several variations...

Realizing Trigonometric Functions with the Multifunction Converter LH0094:  National Semiconductor - Application Note  (app note added 2/06)

Reference stabilizes exponential Current:  10/25/01 EDN Design Ideas  /  (added 1/05)  In an antilog converter, the difference between the base voltages of two transistors sets the ratio of their collector currents: The use of matched transistors balances the first-order temperature coefficient but leaves a temperature-dependent gain term, q/kT. Classic antilog circuits use a thermistor in the drive circuitry to correct this temperature dependency. ...

Resistance calculator yields precise values:  08/03/95 EDN-Design Ideas / (added 2/06)   

Signed Integer Arithmetic on the HPC:  National Semiconductor - Application Note  (app note added 2/06)

Theory and Applications of Logarithmic Amplifiers:  National Semiconductor - Application Note  (app note added 2/06)

Versatile Power supply load uses light Bulbs:  02/07/02 EDN Design Ideas  /  (added 1/05)  Improvising loads for bench-testing and designing power supplies is often a frustrating and sometimes hazardous experience. When you push large power resistors to their limit, they tend to burn benches and melt solder connections. Many electronic loads are on the market but are usually expensive and of laboratory-type precision and often represent overkill for the average designer. ...

White LED Driver provides 64 step logarithmic dimming:  06/10/04 EDN Design Ideas  /  (added 1/05)  The circuit in this Design Idea is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3V source.