Chip vendors zero in on wireless Product News 5/29/2003 Post a comment Power-managing ICs in wireless products are now playing a major role in system-level solutions. Cell phones, which are being combined with PDAs and cameras, are becoming increasingly small, dense and power-hungry, offsetting the size and energy density advances made by the lithium-ion battery sources powering them.
Constant current regulation overcomes LED quality variations News & Analysis 5/28/2003 Post a comment White LEDs are displacing cold cathode ray tubes as the preferred backlight for small CRT displays. While the prices of white LEDs have dropped, there is still a great deal of manufacturing inconsistency. A dim LED on an array of four or six will create a noticeable dark spot on a small LCD screen. The solution, explains Maxim's cell phone apps manager, is a constant current topology-one that supports both serial and parallel LEDs.
Current, voltage and temperature govern Li-Ion battery charging News & Analysis 5/28/2003 Post a comment Portable applications have many unique battery requirements. They require a high-energy density to provide both transient and continuous power. They need to be lightweight with small footprints, and they need to be safe from potential abuse. But how do you charge these devices. From the May issue of Planet Analog magazine, a National Semiconductor applications engineer discusses charging circuits and scenarios for a variety of chemistries.
Current, voltage and temperature govern Li-Ion battery charging - Part 2 News & Analysis 5/28/2003 Post a comment Portable applications have many unique battery requirements. They require a high-energy density to provide both transient and continuous power. They need to be lightweight with small footprints, and they need to be safe from potential abuse. But how do you charge these devices. From the May issue of Planet Analog magazine, a National Semiconductor applications engineer discusses charging circuits and scenarios for a variety of chemistries.
Simple high-resolution bar-graph display architecture uses analog comparator News & Analysis 5/20/2003 Post a comment Traditional bar-graph display adapter circuits have either employed large arrays of low-accuracy analog comparators or microprocessors with additional I/O porting to drive the multiplicity of indicators involved. These methods generally suffer from lack of dynamic-range and resolution due to the poor analog precision involved, leading to highly complicated workarounds. A Linear Technology guru shows how an analog comparator can provide 60dB precision.
Programmable analog parts make a tough filter design easy News & Analysis 5/20/2003 Post a comment Filter designs can feel like an adventure into an uncharted jungle. New traps and dangers seem to appear out of nowhere, writes an Anadigm applications engineer in the May issue of Planet Analog magazine. He shows us how to implement a voiceband filter with a programmable analog device - and compares the process with one using separate op amps and passive components. Either way, the result is a fairly sharp filter curve.
Flexible circuits for disk drive applications need careful design and characterization News & Analysis 5/14/2003 Post a comment The interconnect between the pre-amplifier and the read/write magnetic head assembly in a hard disk drive must allow HDDs to read and write huge amounts of data at multi-Gbits/s rates. However, undesired effects, such as crosstalk, overshoots, and undershoots often hinder the performance of the interconnect. Ansoft and 3M engineers offer a walk-through on the design and modeling of a flex circuit.
Microprocessor interfacing offers real world choices News & Analysis 5/14/2003 Post a comment Embedded systems are required to operate over wider input voltage ranges while microcontroller operating voltages are decreasing. Taking an analog signal with a wide operating range and interfacing it to an MCU with a lower threshold is a task that is no longer suitable for discrete components. Motorola engineers show some options, using a popular microcontroller as the design example.
ESCWell ARMed and More News & Analysis 5/6/2003 Post a comment The well-attended April Embedded Systems Conference (ESC) in San Francisco proved to be a shot-in-the-ARM for the electronics industry. Jim Lipman provides a wrap-up of the most exciting news out of ESC.
Innovation powers the 'camera phone' News & Analysis 5/2/2003 Post a comment One of the most amazing trends of recent times in ultraportable applications is convergence: smart phones that blend cell phones with PDAs, digital still cameras (DSCs), music players and global-positioning systems (GPSes); audio video recorders that contain camcorders, DSCs, audio players, voice recorders and movie viewers; and digital paper for paper, displays, printers and copiers.