New Industry Products

NEC Electronics Introduces 8-Bit Microcontrollers With Integrated Constant High-Current Drivers

April 22, 2009 by Jeff Shepard

NEC Electronics introduced a new 8-bit All Flash™ general-purpose microcontroller (MCU), the µPD78F8025, with integrated constant high-current drivers, and 32KB of flash memory, which expands the µPD78F8024 product line. The new device is suitable in applications such as home electric cookers, battery chargers, and light-emitting diode (LED) lighting. Based on the µPD78F8024 MCU, an NEC Electronics’ all flash 78K0/KB2 MCU with integrated constant high-current drivers, the µPD78F8025 has expanded memory of 32KB to meet increasing software requirements.

NEC Electronics’ new µPD78F8025 MCU features: (1) integration of an All Flash MCU and constant current driver in a single-chip for smaller board space and fewer off-chip components; (2) NEC Electronics’ All Flash MCU with an A/D convertor, and I²C and UART interfaces, offering precise sensing and flexible communication interface; and (3) built-in current drivers with protection circuits for efficient and highly reliable drive systems. Both the new µPD78F8025 and µPD78F8024 devices offer higher performance in a compact single-chip design.

According to the company, due to their small profiles, lower power consumption and longer life, LEDs have been used increasingly in many lighting systems such as general lighting for home and office, indoor/outdoor signs and displays, and backlight systems in LCD panels. Most systems are designed with separate MCUs and discrete components, such as transistor diodes and voltage control driver ICs. Manufacturers are concerned about performance, power consumption and increasing compact board design. To address these concerns, NEC Electronics introduced the µPD78F8024 device last year, combining its low-power 78K0/KB2 MCUs, with constant current drivers, and following the success of the µPD78F8024 MCU, the new µPD78F8025 expands the flash memory to 32KB to meet the increasing software requirement.

Both chips integrate NEC Electronics’ 78K0/KB2 MCU and a 4-channel constant current driver in a single flat package. The µPD78F8024 and µPD78F8025 chips merge two components into one, providing approximately a 10-percent board space savings and making system development easier.

Both the µPD78F8024 and µPD78F8025 devices have several interfaces, such as an I²C and UART, offering flexibility to communicate with other components. The on-chip 10-bit A/D converter can be used in light sensing, temperature sensing and fine-grained control of a power supply. The on-chip flash memory makes it easy to save any system-control or user data.

In addition to constant-current circuits, the chips integrate protection circuits such as over-current, thermal shutdown and voltage lockout to improve power control, efficiency and reliability of the overall system. Both the µPD78F8024 and µPD78F8025 chips can be used in voltage booster topology or buck topology, giving flexibility to designers to construct optimal systems.

NEC Electronics sees these chips as the first in a series of new power-control devices that can provide development of compact and energy-efficient LED lighting systems and other applications, and plans to market them actively. A full evaluation kit is also available, along with comprehensive development tools.

Samples of NEC Electronics’ µPD78F8025 device are available now, starting at US$5 per unit. Mass production is slated to begin in 2010, with expected monthly mass production of 4,000,000 units.