Calibrated trim tool tweaks multiturn pots :  01/07/99 EDN-Design Ideas / (added 11/05) [Note:  File contains multiple circuits scroll to find this circuit]  Many analog circuits contain multiturn trimming potentiometers whose settings you may need to change during maintenance or calibration. Also, some instruments have panel-mounted potentiometers that may need periodic adjustments. After disturbing....

Circuit forms industrial grade digital potentiometer:  09/20/01 EDN Design Ideas  /  (added 1/05)  Both ac and dc motors in modern industrial systems often receive their control from PLCs (programmable-logic controllers) in a control room safely away from the process. If an operator must manually set the motor speed while observing the process, the component of choice is usually an industrial-grade potentiometer. ...

CMOS IC Makes Low Cost Digital Potentiometer:  01/18/96 EDN-Design Ideas / (added 08/05) A growing trend in the design of electronic equipment is to replace analog knobs used to increase or reduce a continuous signal (such as volume or brightness) with "up" and "down" keys. However, replacing a low-cost analog potentiometer with a digital potentiometer can be costly. The low-cost circuit in Figure 1 can eliminate the analog potentiometer in many applications. The circuit is based on a 16-channel CMOS multiplexer/demultiplexer and a string of resistors.

Communicating with Daisy Chained MCP42XXX Digital Potentiometers:  Microchip Application Note Published 2-Apr-01   (app note added 2/06)

Comparing Digital Potentiometers to Mechanical Potentiometers:  Microchip Application Note Published 20-Nov-00   (app note added 2/06)

Convert Voltage to potentiometer Wiper setting:  09/05/02 EDN Design Ideas  /  (added 1/05)  The circuit in Figure 1converts an analog input voltage, VIN, to a proportional wiper setting of a DPP (digitally programmable potentiometer). The potentiometer's wiper setting, which varies from position 0 through 31, corresponds to the input voltage, which varies from 0 to 1V dc. The CAT5114, IC5, is a 32-tap potentiometer with an increment/decrement interface....

DC Power Wire also Carries Clock or Data:  03/13/98 EDN-Design Ideas / (added 03/03)   -High-side current-sense amplifier, IC1, offers a simple method of combining low-speed clocks or other signals with dc power in cables between subsystems

Difference Amplifier uses digital potentiometers:  05/30/02 EDN Design Ideas  /  (added 1/05)  You sometimes need to measure a small signal in the presence of a large common-mode signal. Traditional instrumentation amplifiers that use two or three op amps in their internal structure find common use in these applications. The circuit in Figure 1 presents an alternative approach that is useful when low cost and low drift are important, but when you don't need high precision....

Digital Pot Adjusts LCD's Contrast:  02/04/99 EDN-Design Ideas  / (added 5/03)   You can use a digitally controlled potentiometer for many purposes. In this example, you can use the device to regulate the contrast of a standard (such as two lines by 40 characters) LCD. You can use the circuit in Figure 1 in a portable test system, in which you need to change the contrast of the LCD as a function of the viewing angle. You choose the contrast setup from a menu and then use up or down buttons with µC IC1 to adjust the contrast. The µC stores the contrast value in the digital potentiometer, IC2. This design uses a Xicor 10-k unit (dubbed "EEPOT"), but you could use other devices in the design.  The EEPOT connects to the LCD's VO line. You could connect....

Digital Pot Corrects for System Drift:  11/10/94 EDN-Design Ideas / (added 3/03)  The circuit in Fig 1 looks simple but usually comes as a revelation to designers. Under control of the system's µP, the digital potentiometer, IC1, becomes a variable set-point reference that can adapt to the long-term drift of the variable measured. The digital potentiometer replaces schemes involving A/D and D/A converters (see "Autocalibrator nulls dc offsets," EDN, June 9, 1994, pg 139, and "Infinite-hold circuit zeros out long-term drift," EDN, March 3, 1994, pg 90)....  

Digital Potentiometer Controls LCD Bias:  03/17/94 EDN-Design Ideas / (added 03/03) Designers of pen-based computers can easily relegate some controls that were previously mechanical, such as switches and potentiometers, to on-screen icons. For example, the circuit in Fig 1 shows one way that digital logic can control the -24V-dc LCD bias using two general-purpose I/O command lines. The DS-1669 from Dallas Semiconductor is a 64-step potentiometer available in 10-, 50-, and 100-kV ranges. The up-count (UC) .....

Digital Potentiometer Controls Phase Shift:  02/15/96 EDN-Design Ideas / (added 3/03)  

Digital potentiometer Programs and stabilizes Voltage Reference:  05/30/02  EDN Design Ideas / (added 10/03)    The potentiometer portion of a mixed-signal, digitally programmable potentiometer adds variability to an analog circuit, and its digital controls provide programmability. You can use a digital potentiometer in two ways in an analog circuit. You can use it as a two-terminal variable resistance, or rheostat, or as a three-terminal resistive divider..

Digital potentiometers enable Programmable Biquadratic filter:  07/22/04 EDN Design Ideas  / (added 11/05)  Of the many types of analog filters available to designers, few allow easy adjustments of the filter parameters. The biquadratic, or biquad, filter is an exception, however. You can change that filter's corner frequency (ω0), Q, and gain (H) by adjusting the values of three resistors. For that purpose, the lowpass biquad circuit of Figure 1 includes three digital potentiometers configure...

Digital Potentiometers Overview:  Information about digitally-controlled solid-state electronic potentiometers from Dallas Semicondictor... (app note added 11/06)

Digital Potentiometers: Frequently Asked Questions:  Maxim Application Notes / 593 / Nov-05  (app note added 6/06)

Digital Stereo Potentiometer:  in PDF format, text in Finnish (added 1/03)

Digital Volume Control:  based on DS1669 Digital Pot IC (added 5/02)

Digital volume Control has log taper:  04/11/02 EDN Design Ideas  /  (added 1/05)  Digital potentiometers provide a compact and convenient way to attenuate audio-amplifier signals. However, most such potentiometers suffer from at least one flaw: a nonlogarithmic step increment. To avoid this problem, a user must usually step the potentiometer in a nonlinear sequence to simulate a logarithmic taper. ...

Digitally controlled potentiometer sets cutoff frequency:  06/10/99 EDN-Design Ideas / (added 2/06)

Electronic potentiometer system has pushbutton interface:  09/26/02  EDN Design Ideas / (added 10/03)    As systems grow smaller, it becomes increasingly attractive to replace mechanical potentiometers with electronic potentiometers, which are smaller and less expensive silicon equivalents. A common interface for such devices comprises a Chip-Select, Increment and, Up/ line. CS activates the device and, on a rising edge of steps the wiper in a direction that the U/ pin indicates..