LEDディスプレイドライバ内蔵3 1/2及び4 1/2桁ADC、設計時間を短縮し、省スペース
SUNNYVALE, CA-December 3, 2003-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX1497. This IC is part of the MAX1495*-MAX1499* and MAX1447* family of 3.5- and 4.5-digit sigma-delta analog-to-digital converters (ADCs) with integrated LED display drivers. These devices are ideal for panel-meter applications. The MAX1495-
MAX1499 and MAX1447 integrate an on-chip oscillator and internal 2.048V reference in 28-pin SSOP or 32-pin TQFP packages, resulting in a 10x reduction in footprint when compared to the ICL7137CPL. These ADCs provide greater than 100dB of simultaneous 50Hz/60Hz noise rejection. They accept a bipolar ±2V or ±200mV differential input, include hold/peak functions, and contain a low-battery indicator. These devices consume only 900µA (typ) using a single 2.7V to 5.25V supply.
The MAX1495-MAX1499 and MAX1447 eliminate the external integrating and autozeroing capacitor required for competitive solutions such as the industry standard ICL7137. Those external capacitors require exceptional dielectric characteristics and are sensitive to leakage currents. Because those capacitors contribute most of the measurement errors in dual-slope ADCs used in industry-standard products such as the ICL7137, eliminating them on the MAX1495-MAX1499 and MAX1447 directly improves measurement accuracy and simplifies design.
The MAX1497/MAX1499 offer an optional SPI™-/QSPI™/
MICROWIRE™-compatible serial interface for independent control of the ADC and LED drivers. This allows processing by a microcontroller (µC) before displaying the ADC result, making these devices ideal for nonlinear measurements like thermocouples, or for multifunction microprocessor-based panel-meter products. To display custom messages on the LED display, the MAX1497/MAX1499 allow individual control of each LED segment.
The MAX1496* 3.5-digit stand-alone and the MAX1497 3.5-digit µC interface devices are available in 28-pin PDIP and 28-pin SSOP packages. The MAX1498*/MAX1447 4.5-digit stand-alone and the MAX1499 4.5-digit µC interface ICs are available in a 7mm x 7mm, 32-pin TQFP package. Each device is available in the extended (-40°C to +85°C) temperature range. Prices start at $3.96 (1000-up, FOB USA).
*Future product-contact factory for availabilty.
SPI/QSPI are trademarks of Motorola Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
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