MAX1497, MAX1499 3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and µC Interface

3.5- and 4.5-Digit ADC, LED Display Drivers Reduce Time and Save Board Space

Status

Active: In Production.

Description

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The MAX1497/MAX1499 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated lightemitting 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.

The MAX1497/MAX1499 do not require external precision integrating capacitors, autozero capacitors, crystal oscillators, charge pumps, or other circuitry required with dual-slope ADCs (commonly used in panel meter circuits).

These devices also feature on-chip buffers for the differential signal and reference inputs, allowing direct interface with high-impedance signal sources. In addition, they use continuous internal offset-calibration and offer >100dB rejection of 50Hz and 60Hz line noise. Other features include data hold and peak detection, overrange and underrange detection, and a user-programmable low-battery monitor.

The MAX1499 is available in a 32-pin, 7mm x 7mm TQFP package and the MAX1497 is available in 28-pin SSOP and 28-pin PDIP packages. All devices in this family operate over the -40��C to +85��C extended temperature range.

An evaluation kit is available: MAX1499EVKIT

Key Features		Applications/Uses
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)		Digital Multimeters Digital Panel Meters Digital Voltmeters Handheld meters