General Description

The MAX1497/MAX1499 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated light emitting diode (LED) drivers operate from a single 2.7V to 5.25V power supply. They include an internal reference, a high-accuracy on-chip oscillator, and a multiplexed LED display driver. An internal charge pump generates the negative supply needed to power the integrated input buffers for single-supply operation. The ADC is configurable for either a ±2V or ±200mV input range and it outputs its conversion results to an LED and/or to a microcontroller (μC). Microcontroller communication is possible through an SPI?-/QSPI?-/MICROWIRE?-compatible serial interface. The MAX1497 is a 3.5-digit (±1999 count) device and the MAX1499 is a 4.5-digit (±19,999 count) device.

特性 Features

? High Resolution

??? MAX1499: 4.5 Digits (±19,999 Count)

??? MAX1497: 3.5 Digits (±1999 Count)

? Sigma-Delta ADC Architecture

??? No Integrating Capacitors Required

??? No Autozeroing Capacitors Required

??? >100dB of Simultaneous 50Hz and 60Hz

??? Rejection

? Operate from a Single 2.7V or 5.25V Supply

? Selectable Input Range of ±200mV or ±2V

? Selectable Voltage Reference: Internal 2.048V or External

? Internal High-Accuracy Oscillator Needs No External Components

? Automatic Offset Calibration

? Low Power (Exclude LED Driver Current)

??? Maximum 664μA Operating Current

??? Maximum 268μA Shutdown Current

? Small 32-Pin, 7mm x 7mm TQFP Package (4.5 Digits), 28-Pin SSOP Package (3.5 Digits)

? Also Available in a PDIP Package (3.5 Digits)

? Multiplexed LED Drivers Resistor-Programmable Segment Current

? SPI-/QSPI-/MICROWIRE-Compatible Serial Interface

? Extended Temperature Range (-40°C to +85°C)

Applications

??? Digital Panel Meters

??? Hand-Held Meters

??? Digital Voltmeters

??? Digital Multimeters