MicroConverters rev processing capacity

MicroConverters rev processing capacity
Norwood, Mass. - Analog Devices Inc. has launched three additions to its MicroConverter family, devices that pair precision data converters with 8-bit 8052 flash microcontrollers for intelligent-sensor applications.

The AduC844, AduC845 and Adu-C846 offer higher resolution and 12 times greater processing capacity than their predecessors, ADI said. They incorporate 16- and 24-bit analog-to-digital converters, whereas earlier versions were based on 12-bit converters. The products' 8052 core has been optimized to run at one clock cycle per instruction cycle instead of 12 clocks per instruction, said Brian O'Mara, applications manager for MicroConverter and instrumentation converter products at ADI, here.

O'Mara said MicroConverters are used in applications that call for precise measurement of low-frequency signals with a wide dynamic range. Examples include intelligent-sensor calibration and conditioning, smart transmitters, weigh scales, temperature and pressure transducers, 4- to 20-mA control loops, patient-monitoring equipment and portable test-and-measurement gear.

The single-cycle 8052 flash microcontroller core common to all three new MicroConverters runs at up to 12.58 Mips and offers 8051 instruction-set compatibility. The memory section consists of on-chip code flash/EE memory space for in-circuit reprogrammability, a nonvolatile read/write block of data memory space with security enhancements and 2,304 bytes of RAM.

The ADuC844 includes a 24-bit primary and a 16-bit auxiliary sigma-delta A/D while the AduC846 includes two 16-bit sigma-delta converters. The two offer 105-Hz maximum A/D throughput. The AduC845 includes two 24-bit sigma-delta A/Ds and a 10-channel (five-differential-channel) input multiplexer. Its maximum throughput is 1.3 kHz .

All three devices include a temperature sensor; a programmable-gain amplifier on the primary A/D to allow direct measurement of low-level signals; a 12-bit voltage output digital-to-analog converter; and dual pulse-width modulation outputs. Two current sources, a reference and an oscillator are on board, and a phase-locked loop generates the 12.58-MHz clock from a 32-kHz crystal. UART, SPI and I2C communications ports are included.

Chopping scheme
O'Mara noted that the primary and auxiliary A/Ds in all three MicroConverters implement a patented chopping scheme that improves dc offset and offset-drift specifications.

Support tools available for the MicroConverters include QuickStart, an entry-level system for developing, debugging and testing applications in assembly, and QuickStart Plus, which includes a C compiler, macro assembler, simulator and real-time emulator.

The ADuC844 and ADuC846 are sampling now, while the ADuC845 is to sample in July. In 1,000-piece quantities, smaller-memory versions of the trio are priced at $8.45, $7.17 and $9.24, respectively. Each is available in an 8 x 8-mm, 56-lead chip-scale package and a 52-pin PQFP. QuickStart is priced at $75 and QuickStart Plus at $299.

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