Large LCD Panel (14 to 24 inch):  Intersil Application Block Diagram  (app note added 6/06)

Layout and Grounding Recommendations for Touch Screen Digitizers:  AN-577 Analog Devices Application Notes  (app note added 6/06)

LCD Backlight Inverter Drive IC (FAN7310) / AN-4143:  Fairchild Application Notes / (app note added 6/06)

LCD Direct Drive using HPC:  National Semiconductor Application Note   (app note added 2/06)

LCD Fundamentals using PIC16c92x Microcontrollers:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

LCD Interface Saves µC I/O Pins:  12/12/97 EDN-Design Ideas / (added 3/03)  

LCD Interface Takes Two Wires:  03/26/98 EDN-Design Ideas / (added 03/03)  

LCD Monitor Applications / AB-50:  Fairchild Application Notes / (app note added 6/06)

LCD Monitor Applications / AB-51:  Fairchild Application Notes / (app note added 6/06)

LCD Serial Terminal:  has RS-232 serial in/out, up to 20 programmable keys, Character LCD up to 2x40, 5 auxiliary inputs, 6 auxiliary outputs. (added 7/03)

LCD Thermometer:  (app note added 6/03)

LCD Triplex Drive with COP820cj:  National Semiconductor Application Note   (app note added 2/06)

LCD-TV Panel:  Intersil Application Block Diagram  (app note added 6/06)

LED Barograph Driver:  (electronic schematic added 7/02) Fair Warning: this site has pop-up ads

LED Driver Combines High Speed Precision:  08/21/03 EDN Design Ideas  /  (added 1/05)  Applications such as turbidity measurement and densitometry require cleanly pulsed light sources with stable amplitudes. The LED driver in Figure 1 illuminates retinal neurons in a biological experiment that has similar requirements. For a given LED at a given current, the intensity is stable, so switching a stable current is a simple and effective way to obtain the needed function....

LED Driver Delivers Constant Luminosity:  06/12/03 EDN Design Ideas  /  (added 1/05)  The circuit in Figure 1 is similar in principle to that of a previous Design Idea (Reference 1) but offers improved, more reproducible performance. The output current is almost constant over an input-voltage range of 1.2 to 1.5V and is insensitive to variations of transistor gain. Transistors Q1 and Q2 form an astable flip-flop....

LED Driver Displays Standing Wave Radio:  03/18/99 EDN-Design Ideas / (added 6/03) The circuit in Figure 1 uses an LM3914 LED driver to directly display standing-wave ratio (SWR) in a low-cost, rugged instrument. The SWR-sensing head is derived from the ARRL Antenna Handbookin an article that describes the tandem match. The forward voltage and reflected voltage (VF+VR ) signal drives Pin 6 (RHI ), and the VF–VR signal drives the normal signal input at Pin 5. You can use this basic arrangement to display the ratio of two voltages in other applications. The internal circuit of the LM3914 comprises 10 voltage comparators that compare....

LED Driver Doubles as Fault Monitor:  08/05/04 EDN Design Ideas  / (added 11/05)  LEDs find wide use as indicators and as light emitters in devices such as optocouplers. In some applications, the LED or the emitter may be located remotely at some distance from the main unit. Typical examples are dashboard-mounted automotive indicators and industrial optosensors. In critical applications, you may require some means of monitoring the integrity of the LED.

LED Driver Provides Oscillator for Microcontroller:  09/16/04 EDN Design Ideas  / (added 11/05)  The major building blocks for a white-LED driver are an oscillator, a charge pump, and a regulated current source. National Semiconductor (www.national.com ) produces a device that contains all these building blocks in the highly integrated LM2791/2 IC. You usually use white-LED drivers in tandem with cellular baseband controllers or microcontrollers.

LED Driver Provides Software Controlled Intensity:  09/30/04 EDN Design Ideas  /  (added 10/05)  Recent advances in operating efficiency have expanded the use of LEDs from one of mere indicators to becoming driving forces in electronic lighting. Increased reliability and ruggedness (versus other lighting technologies) gives the LED a bright future indeed. Vendors in recent years have introduced many ICs for driving LEDs, but the problem of driving serial chains of LEDs has received less at......

LED Sign:  uses two LED arrays to form a 7 X 10 matrix. It produces moving messages or animations stored in an EPROM. (added 7/03)

LED-Based Message Display:  (circuit / schematic design added 6/06)

Level Shifter Follows Negative Output:  11/23/94 EDN-Design Ideas / (added 3/03) Transistors Q1 and Q2 in Fig 1, develop a feedback signal of the proper positive polarity for regulator IC1 from the circuit's negative output. You can use this simple technique to sense any negative-voltage output. The regulator drives a charge pump comprising L1(Sumida, Arlington Heights, IL, (708) 956-0666), C1, C2, D1, and D2. When the regulator's switch is on, current builds in inductor L1. At the same time, the charge on C1 transfers to the output capacitor, C2. During the switch's off time, energy stored in the inductor charges capacitor C1....  

Line Driver Economically Synthesizes Impedance:  01/06/94 EDN-Design Ideas  / (added 3/03) The line-driver circuit in Fig 1 uses a second op amp to synthesize the output impedance. The conventional line-driver circuit employs a single op amp having a resistor whose resistance is equal to the desired impedance in series with the op amp's output. The principal drawback of the conventional circuit is that the single op amp must deliver twice the needed output voltage because of the large voltage drop across the output resistor. The circuit in Fig 1is similar to the famous Howland current pump but has different resistor values. To calculate the output resistance, RO, short the input to ground. Then....

Low Cost Lcds Implement Bar Graph Displays:  09/12/97 EDN-Design Ideas / (added 2/06)  

Low Power RS-232c Driver and Receiver in CMOS:  National Semiconductor Application Note 05 Oct1998 / (app note added 5/02)

LT1399/LT1399HV Triple 300MHz Current Feedback Amplifiers Drive Component Video and LCD Displays:  DN213  Design Notes (Linear Technology) (app note added 6/06)

LVDS Display Interface:  National Semiconductor Application Note   (app note added 2/06)