Add gain to an absolute value amplifier: 08/22/2002  EDN - Design Ideas / The absolute-value amplifier is a basic building block in test-and-measurement and signal-processing applications. The addition of a DPP (digitally programmable potentiometer) adds another dimension, G (gain), to this key circuit. Because the gain is programmable, you can use the circuit as an absolute-value amplifier (G<1) or an absolute-value attenuator (G>1)

Circuit forms industrial grade digital potentiometer: 09/20/2001 EDN - Design Ideas /  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 proc.

CMOS IC Makes Low Cost Digital Potentiometer: 01/18/96 EDN-Design Ideas

Convert voltage to potentiometer wiper setting: 09/05/2002  EDN - Design Ideas / 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 / 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: 05/30/2002  EDN - Design Ideas / 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  / PDF contains multiple circuits - scroll to find circuit.

Digital Pot Corrects for System Drift: 11/10/94 EDN-Design Ideas

Digital Potentiometer Controls LCD Bias: 03/17/94 EDN-Design Ideas

Digital Potentiometer Controls Phase Shift: 02/15/96 EDN-Design Ideas

Digital potentiometer programs and stabilizes voltage reference: 05/30/2002  EDN - Design Ideas /  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 Stereo Potentiometer: in PDF format, text in Finnish

Digital volume control has log taper: 04/11/2002  EDN - Design Ideas / 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.

Digital Volume Control: based on DS1669 Digital Pot IC

Digitally Controlled Phase Shift: Altering the phase response of a signal without changing its amplitude characteristics is commonly performed using an all pass filter. This circuit implementation is well suited to using digital potentiometers as the controlling element.

Electronic potentiometer system has pushbutton interface: 09/26/2002  EDN - Design Ideas / 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..

Inexpensive Relays Form Digital Potentiometer: 03/13/98 EDN-Design Ideas / Build a digitally controllable isolated potentiometer that can tolerate voltages up to 60-Volt dc

LED Light Dimmers uses only Two Lines: 03/21/02 EDN-Design Ideas / PDF contains multiple circuits - scroll to find the one of interest -- This circuit provides32 steps of brightness control (from0 to100%) for a backlight or instrument panel, using just two general-purpose-microprocessor signals.  Although the circuit shows the circuit driving white LEDs, the load could also be a dc motor or an incandescent lamp. The basis of the circuit is a modified Schmitt-trigger relaxation oscillator controlled by MAX5160 digital potentiometer.

Linear Potentiometer implements Logarithmic Gain Control: 10/23/97 EDN-Design Ideas / Trimmer potentiometers are ubiquitous components and are available in a variety of packages, Resolutions, and temperature stabilities but none of these potentiometers implements anything but the usual linear function of resistance vs. shaft position as useful in many audio applications

Negative Resistance Nulls Potentiometer's Wiper Resistance : 02/04/02 Electronic Design - Ideas for Design / While almost always called "potentiometers" (which are technically defined as three-terminal variable voltage dividers), many "pots" actually end up being used as variable resistors (rheostats) instead. When used as a variable resistor, all...  

Network Forms Digital to Impedance Converter: 03/14/96 EDN-Design Ideas

One amplifier has two gain figures: 09/19/2002  EDN - Design Ideas / The single-supply circuit in Figure 1 is an inverting amplifier with two outputs—one for positive output voltages, VOUT(POS), and the other for negative output voltages, VOUT(NEG). Steering diodes D1 and D2 split the amplifier, IC1, output into the two output polarities relative to the 2..

PIC NiCd Battery Charger:

Programmable oscillator uses digital potentiometers: 03/07/2002  EDN - Design Ideas / Digital potentiometers are versatile devices; you can use them in many filtering and waveform-generation applications. This Design Idea describes an oscillator in which setting the resistance of two digital potentiometers independently programs the oscillation amplitude and frequency. Figure 1 shows a typical diode-stabilized Wien-bridge oscillator that generates accurate sine waves fro... .

Programmable oscillator uses digital potentiometers: 03/07/2002  EDN - Design Ideas / Digital potentiometers are versatile devices; you can use them in many filtering and waveform-generation applications. This Design Idea describes an oscillator in which setting the resistance of two digital potentiometers independently programs the oscillation amplitude and frequency. Figure 1 shows a typical diode-stabilized Wien-bridge oscillator that generates accurate sine waves fro... .

Pushbutton Switch Controls Power Supply & �C: 11/19/98 EDN-Design Ideas

Rotary encoder mates with digital potentiometer: 03/06/03  EDN-Design Ideas / In developing electronic systems, designers look for products or ideas that may benefit from the better performance, smaller size, lower cost, and improved reliability that an IC can offer. Toward that end, the digital potentiometer emerged as an alternative to its mechanical counterpart, the mechanical potentiometer...

Single switch controls digital potentiometer: 02/07/2002  EDN - Design Ideas / The control of electronic potentiometers in most today's applications comes from controller-generated signals. However, a significant number of applications exist that require adjustments using manual, front-panel controls. The circuit in Figure 1 uses one IC, one switch, and 10 discrete components. .

Single switch controls digital potentiometer: 09/19/2002  EDN - Design Ideas / This Design Idea is an evolution and simplification of another (Figure 1, Reference 1). Replacing the three inverted-input NOR gates with their logical equivalents, positive-input NAND gates, makes these three gate symbols consistent with the fourth, which was drawn as a positive-input NAND gate. The 74HC132's data sheet describes the device as a quad, two-input NAND gate with hysteresis..

Soft Start Circuit for Power Amps:

Tack a Log Taper onto a Digital Potentiometer: 01/20/00 EDN-Design Ideas / PDF contains multiple circuits - scroll to find the one of interest / idea to convert linear digital potentiometer to a logarithmic digital potentiometer

Tiny Programmable Oscillator With 5Khz to 20Mhz Span: By merging a digital potentiometer with an oscillator chip, we can make a very small programmable oscillator (1 uMAX and1 SOT23 package). Not only does this circuit take up very little board space but it can be controlled with only three signals from a microprocessor.

Use Rotary Potentiometer To Drive Solid State Volume Control: 01/20/03 Electronic Design - Ideas for Design /  This design idea details how a standard volume control can be replaced by its solid-state equivalent. Digital potentiometers are often advertised as replacements for rotary volume controls. To simulate these controls, many circuits employ up/down...

Voltage Regulator goes Digital: 11/24/99 EDN-Design Ideas / Power consumption and failing batteries are key issues in battery-operated applications. Features in the new generation of series voltage regulators address these concerns. For example, National Semiconductors LP2951 MicroPower voltage regulator provides a logic-level output signal indicating a low regulated output voltage; the IC also has a logic-level input to shut down the regulator to conserve power.

Where is the wiper?: 08/08/2002  EDN - Design Ideas /  You enjoy significant advantages when using DPPs (digitally programmable potentiometers) with increment/decrement serial interfaces. Programming the serial interface is simple and fast, and you can adjust the potentiometer in real-time applications. The interface, however, provides no information about wiper position, and this information is important in some applications..