Serial 8-bit data programs digital pot for logarithmic control News & Analysis 6/25/2003 Post a comment The Winbond WMS720x series is a family of 256 linear step, software controlled digital potentiometers. Some applications require logarithmic steps however, for example an audio volume control. The relatively large number of steps available in the WMS720x series allows us to use software to approximate logarithmic operation in that kind of application. This feature will investigate how this may be done, present a solution and will analyze the step accuracy inherent in the application.
Programmable power manager IC sequences multiple voltages News & Analysis 6/25/2003 Post a comment Increasingly, inter-device communication standards also require the use of a variety of I/O supply voltages - all different from the core operating voltage. These factors result in devices, cards and systems with multiple power supply requirements. Sequencing becomes an issue. A Lattice Semiconductor engineer shows how multiple supply rails can be ramped up using a programmable analog device.
Product Focus: A/D Converters News & Analysis 6/21/2003 Post a comment Facing customer pressure to reduce board space requirements and improve
performance, makers of analog-to-digital converters are integrating
signal-conditioning functionality into their products in hopes of furthering both objectives. Analog Devices, Linear Technology, Maxim Integrated Products, National Semiconductor and Texas Instruments are among those offering A/Ds that tout signal quality, hand customers the ability to control signal parameters or both.
How "digital" is your Digital Still Camera? Teardown 6/18/2003 Post a comment There's a ton of analog in the so-called "digital" camera. The image capture front end, optical control, and power management sections are all analog, writes Portelligent's David Carey is this exclusive teardown report for the June issue of Planet Analog magazine. But except for the analog image processor, the ICs suppliers for the Olympus C50 are not the usual suspects.
Reverse Media Independent Interface (RevMII) Block Architecture Design How-To 6/18/2003 Post a comment This article describes a design of a simple digital device able to connect two Ethernet MACs with configurable point-to-point link (Reverse MII Interface block). This link is proposed to be a simple and low-cost alternative to using Ethernet PHY in the system. The block might be used either inside an ASIC or on the system board (FPGA). The device described emulates two Ethernet PHY-level blocks connected together and is completely transparent to Ethernet MACs.
Where Did All This Noise Come From? News & Analysis 6/17/2003 Post a comment Remember when 3nV/sq-rt Hz was a to-die-for spec? Bill Klein is back with a new installment of his popular I took a call last week column. This one looks at the tradeoffs between op amp noise and current consumption. You dont get low noise without taking a hit on current. Some math (just a little bit) explains why.
Advanced DSP supports home theater and surround-sound audio - Part 2 News & Analysis 6/17/2003 Post a comment All home theater systems, from the most exotic to the most inexpensive, depend on some form of digital signal processing to increase fidelity, expand the number of audio channels, and enhance the "you-are-there" experience of DVD movies and audio. Some of these processing tasks involve front-end detection; others involve post-processing after the channels have been separated. Analog Devices' engineers explain some of the decoding algorithms the processor must handle.
Advanced DSP supports home theater and surround-sound audio - Part 1 News & Analysis 6/17/2003 Post a comment All home theater systems, from the most exotic to the most inexpensive, depend on some form of digital signal processing to increase fidelity, expand the number of audio channels, and enhance the "you-are-there" experience of DVD movies and audio. Some of these processing tasks involve front-end detection; others involve post-processing after the channels have been separated. Analog Devices' engineers explain some of the decoding algorithms the processor must handle.
Vitesse to buy distressed Multilink News & Analysis 6/10/2003 Post a comment Vitesse Semiconductor Corp. said it has agreed to pay approximately $23 million for struggling Multilink Technology Corp., in a sign that suppliers to the sluggish communications equipment market continue to struggle for survival.
Programmable Analog Parts Make a Tough Filter Design Easy News & Analysis 6/9/2003 Post a comment Filters have always presented some of the toughest challenges in analog design: the math is difficult, the circuit selection is based on a variety of subtle criteria, and the component tolerances are critical. Tradeoffs between the variables are time-consuming and not always well defined.
Tracking feature simplifies simultaneous power supply voltage sequencing News & Analysis 6/4/2003 Post a comment The ability to sequence the power-up of multiple supply voltages in complex logic and mixed signal applications has become an important requirement for power system designers. This is because most VLSI logic devices, including DSPs, ASICs, FPGAs, and microprocessors, now require at least two supply voltages. This includes a low-voltage to power a logic core, and a standard logic voltage to power the I/O. A Texas Instruments engineer describes how this works with some new-generation modules
GSM power amplifier depends on closed loop control News & Analysis 6/4/2003 Post a comment Managing the power level of a GSM radiophone is a key power management objective. At too high a power level, your phone signal will overpower others within your cell. At too low a level, your caller will experience dropouts. On all the time, the GSM phone will forever endanger your battery life. In this piece, National Semiconductor suggests a means of modulating power levels with an easy-to-implement loop.
National enhances online tool suite News & Analysis 6/2/2003 Post a comment National Semiconductor Corp. today is launching an online enhanced suite of product selection and design tools for its analog chips, betting that easing procurement and time-to-market for its customers will improve sales.