MAX1492:3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers

The MAX1492/MAX1494 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated liquid crystal display (LCD) 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 triplexed LCD driver. An internal charge pump generates the negative supply needed to power the integrated input buffer for single-supply operation. The ADCs are configurable for either a ±2V or ±200mV input range and outputs its conversion results to an LCD and/or to a microcontroller (µC). µC communication is facilitated through an SPI™-/QSPI™-/MICROWIRE®-compatible serial interface. The MAX1492 is a 3.5-digit (±1999 count) device, and the MAX1494 is a 4.5-digit (±19,999 count) device. The MAX1492/MAX1494 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 simultaneous rejection of 50Hz and 60Hz line noise. Other features include data hold and peak hold, overrange and underrange detection, and a low-battery monitor. The MAX1494 comes in a 32-pin, 7mm x 7mm LQFP package, and the MAX1492 comes in 28-pin SSOP and 28-pin PDIP packages. All devices in this family operate over the 0°C to +70°C commercial temperature range.

Key Features
  • High Resolution
    • MAX1494: 4.5 Digits (±19,999 Count)
    • MAX1492: 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
    • Maximum 960µA Operating Current
    • Maximum 400µA Shutdown Current
  • Small 32-Pin 7mm x 7mm LQFP Package (4.5 Digits), 28-Pin SSOP Package (3.5 Digits)
  • Triplexed LCD Driver
  • SPI-/QSPI-/MICROWIRE-Compatible Serial Interface
  • Evaluation Kit Available (Order MAX1494EVKIT)
MAX1492, MAX1494: Typical Operating Circuit
MAX1492, MAX1494: Typical Operating Circuit
  • Digital Multimeters
  • Digital Panel Meters
  • Digital Voltmeters
  • Handheld meters
titleDownload file
MAX1492-MAX1494 Data SheetMAX1492-MAX1494.pdf
Part NumberResolution
Conv. Rate
Data BusDiff/S.E. InputInternal VREF
External VREF
External VREF
Bipolar VIN
maxnominalminmaxmaxSee Notes
MAX149220000.00257-SegmentDiff. Only2.04802.04821PDIP(N)/28
$6.82 @1k
MAX149420000LQFP/32$10.47 @500
Design kits & evaluation modules
Related Products
  • MAX1496:3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers
  • MAX1447:3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers
  • MAX1498:3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers
  • MAX1499:3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and µC Interface
  • MAX1497:3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and µC Interface
  • MAX1495:3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers
  • MAX1493:3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers
  • MAX1491:3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1492CAINo Longer AvailableMAX1492CAI+SSOP,;28 pin;81.6 mm²0°C to +70°CSee data sheet
MAX1492CAI+ActiveSSOP,;28 pin;81.6 mm²0°C to +70°CLead Free
MAX1492CAI+TActiveSSOP,;28 pin;81.6 mm²0°C to +70°CLead Free
MAX1492CAI-TNo Longer AvailableMAX1492CAI+TSSOP;28 pin0°C to +70°CSee data sheet
MAX1492CNINo Longer AvailableMAX1492CNI+PDIP(N),;28 pin;289.5 mm²0°C to +70°CNo
MAX1492CNI+No Longer AvailablePDIP(N),;28 pin;289.5 mm²0°C to +70°CLead Free
MAX1492-MAX1494.pdf MAX1494
MAX1492-MAX1494_cn.pdf MAX1494
Delta-Sigma ADCs Replace Integrating ADCs for Panel Meters MAX1499
MAX1492-MAX1494_cn.pdf MAX1494