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

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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.
MAX1497, MAX1499: Typical Operating Circuit MAX1497, MAX1499: Typical Operating Circuit Enlarge+

Key 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)


  • Digital Multimeters
  • Digital Panel Meters
  • Digital Voltmeters
  • Handheld meters

See parametric specs for Display-Oriented ADCs (27)

Part NumberResolution
Conv. Rate
Data BusDiff/S.E. InputInternal VREF
External VREF
External VREF
Bipolar VIN
maxnominalminmaxmaxSee Notes
MAX1497 20000.0057-SegmentDiff. Only2.04802.04821
$8.86 @500
MAX1499 20000
$12.11 @500

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX1499EVKIT: Evaluation Kit/Evaluation System for the MAX1499
Request Reliability Report for: MAX1497 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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