Microchip Technology

The CL88030 and CL88031 LED Driver Integrated Circuits (ICs) are intended offline sequential linear LED drivers designed to provide LED power from a utility voltage input. The CL88030/31 devices are designed to drive a long string of inexpensive, low-current LEDs directly from the AC mains. A basic driver circuit consists of Microchip’s CL88030/31 LED driver IC, four power FETs (six if using the CL88031), four resistors, two capacitors, and a bridge rectifier. Additional components are optional for various levels of transient protection. Adding an inexpensive NTC-thermistor assures over temperature protection (OTP). No EMI filters or power factor correction circuits are needed (unless the optional flicker-reduction feature is desired). A string of series/parallel LEDs is tapped at four (or six) locations, called "taps". Linear current regulators sink current at each tap through a single control point and are sequentially turned on and off. High efficiency is achieved by shutting off upstream regulators when downstream regulators achieve regulation. This makes controlling overall input current easier than trying to control multiple current paths by tracking the input sine wave voltage. The CL88030/31 uses a self-commutation technique using only the tap currents themselves; this technique inherently provides smooth transitions from one regulator to the next, without relying on tap voltages or the rectified AC to coordinate the transitions.

The CL88030 and CL88031 LED Driver Integrated Circuits (ICs) are intended offline sequential linear LED drivers designed to provide LED power from a utility voltage input. The CL88030/31 devices are designed to drive a long string of inexpensive, low-current LEDs directly from the AC mains. A basic driver circuit consists of Microchip’s CL88030/31 LED driver IC, four power FETs (six if using the CL88031), four resistors, two capacitors, and a bridge rectifier. Additional components are optional for various levels of transient protection. Adding an inexpensive NTC-thermistor assures over temperature protection (OTP). No EMI filters or power factor correction circuits are needed (unless the optional flicker-reduction feature is desired). A string of series/parallel LEDs is tapped at four (or six) locations, called "taps". Linear current regulators sink current at each tap through a single control point and are sequentially turned on and off. High efficiency is achieved by shutting off upstream regulators when downstream regulators achieve regulation. This makes controlling overall input current easier than trying to control multiple current paths by tracking the input sine wave voltage. The CL88030/31 uses a self-commutation technique using only the tap currents themselves; this technique inherently provides smooth transitions from one regulator to the next, without relying on tap voltages or the rectified AC to coordinate the transitions.

Microchip's COM20019I is a member of the family of Embedded ARCNET Controllers from Standard Microsystems Corporation. The device is a general purpose communications controller for networking microcontrollers and intelligent peripherals in industrial, automotive, and embedded control environments using an ARCNET protocol engine. The flexible microcontroller and media interfaces, eight-page message support, and extended temperature range of the COM20019I make it the only true network controller optimized for use in industrial, embedded, and automative applications. Using an ARCNET protocol engine is the ideal solution for embedded control applications because it provides a token-passing protocol, a highly reliable and proven networking scheme, and a data rate of up to 312.5 Kbps when using the COM20019I. SOHARD ARCNET Analyzer "SH ARCALYZER-USB" (PCMCIA also available) by clicking this [link](http://www.sohard.de/produkte/arcnet/analyzetools/sh-arcalyzer-usb/ "SH ARCALYZER-USB"). SOHARD ARCNET Analyzer "SH ARCALYZER-USB" (PCMCIA also available)

The COM20022I is a member of the family of Embedded ARCNET Controllers from Standard Microsystems Corporation. The device is a general purpose communications controller for networking microcontrollers and intelligent peripherals in industrial, automotive, and embedded control environments using an ARCNET protocol engine. The small 48 pin package, flexible microcontroller and media interfaces, eight-page message support, and extended temperature range of the COM20022I make it the only true network controller optimized for use in industrial, embedded, and automotive applications. Using an ARCNET protocol engine is the ideal solution for embedded control applications because it provides a deterministic token-passing protocol, a highly reliable and proven networking scheme, and a data rate of up to 10 Mbps when using the COM20022I. A token-passing protocol provides predictable response times because each network event occurs within a predetermined time interval, based upon the number of nodes on the network. The deterministic nature of ARCNET is essential in real time applications. The integration of the 2Kx8 RAM buffer on-chip, the Command Chaining feature, the 10 Mbps maximum data rate, and the internal diagnostics make the COM20022I the highest performance embedded communications device available. With only one COM20022I and one microcontroller, a complete communications node may be implemented. SOHARD ARCNET Analyzer "SH ARCALYZER-USB" (PCMCIA also available) by clicking this [link](http://www.sohard.de/produkte/arcnet/analyzetools/sh-arcalyzer-usb/ "SH ARCALYZER-USB").