MAX1368:Microcontroller-Interface, 4.5-/3.5-Digit Panel Meters with 4-20mA Output

The MAX1366/MAX1368 low-power, 4.5- and 3.5-digit, panel meters feature an integrated sigma-delta analog-to-digital converter (ADC), LED display drivers, voltage digital-to-analog converter (DAC), and a 4–20mA (or 0 to 16mA) current driver. The MAX1366/MAX1368's analog input voltage range is programmable to either ±2V or ±200mV. The MAX1368 drives a 3.5-digit (±1999 count) display and the MAX1366 drives a 4.5-digit (±19,999 count) display. The ADC output directly drives the LED display as well as the voltage DAC, which, in turn, drives the 4–20mA (or 0 to 16mA) current-loop output. In normal operation, the 0 to 16mA/4–20mA current-loop output follows the ±2V or ±200mV analog input to drive remote panel-meter displays, data loggers, and other industrial controllers. For added flexibility, the MAX1366/MAX1368 allow direct access to the ADC result, DAC output, and the V/I converter input. The sigma-delta ADC does not require external precision integrating capacitors, autozero capacitors, crystal oscillators, charge pumps, or other circuitry commonly required in dual-slope ADC panel-meter circuits. On-chip analog input and reference buffers allow direct interface with high-impedance signal sources. Excellent common-mode rejection and digital filtering provides greater than 100dB rejection of simultaneous 50Hz and 60Hz line noise. Other features include data hold and peak detection and overrange/underrange detection. The MAX1366/MAX1368 require a 2.7V to 5.25V supply, a 4.75V to 5.75V V/I supply, and a 7V to 30V loop supply. They are available in a space-saving (7mm x 7mm), 48-pin TQFP package and operate over the extended (-40°C to +85°C) temperature range.

Key Features
  • Microcontroller (µC)-Interface, Digital Panel Meter
    • 20-Bit Sigma-Delta ADC
      • 4.5-Digit Resolution (±19,999 Count, MAX1366)
      • 3.5-Digit Resolution (±1999 Count, MAX1368)
    • No Integrating/Autozeroing Capacitors
    • 100MΩ Input Impedance
    • ±200mV or ±2.000V Input Range
  • LED Display
    • Common-Cathode 7-Segment LED Driver
    • Programmable LED Current (0 to 20mA)
    • 2.5Hz Update Rate
  • Output DAC and Current Driver
    • ±15-Bit DAC with 14-Bit Linear V/I Converter
    • Selectable 0 to 16mA or 4–20mA Current Output
    • Unipolar/Bipolar Modes
    • ±50µA Zero Scale, ±40ppmFS/°C (typ)
    • ±0.5% Gain Error, ±25ppmFS/°C (typ)
    • Separate 7V to 30V Supply for Current-Loop Output
  • 2.7V to 5.25V ADC/DAC Supply
  • 4.75V to 5.25V V/I Converter Supply
  • Internal 2.048V Reference or External Reference
  • SPI™-/QSPI™-/MICROWIRE™-Compatible Serial Interface
  • 48-Pin, 7mm x 7mm TQFP Package
MAX1366, MAX1368: Typical Operating Circuit
MAX1366, MAX1368: Typical Operating Circuit
  • Automated Test Equipment (ATE)
  • Data Acquisition Systems
  • Digital Multimeters
  • Digital Panel Meters
  • Digital Voltmeters
  • Industrial Process Control
titleDownload file
MAX1366-MAX1368 Data SheetMAX1366-MAX1368.pdf
Part NumberResolution
Conv. Rate
Data BusDiff/S.E. InputInternal VREF
External VREF
External VREF
Bipolar VIN
maxnominalminmaxmaxSee Notes
MAX1366200000.005SPIS.E. Only2.048-2.22.221LQFP/48$9.56 @500
Design kits & evaluation modules
Related Products
  • MAX1366:Microcontroller-Interface, 4.5-/3.5-Digit Panel Meters with 4-20mA Output
  • MAX1367:Stand-Alone, 4.5-/3.5-Digit Panel Meters with 4–20mA Output
  • MAX1365:Stand-Alone, 4.5-/3.5-Digit Panel Meters with 4–20mA Output
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1368ECMNo Longer AvailableMAX1368ECM+LQFP;48 pin-40°C to +85°CSee data sheet
MAX1368ECM+ActiveLQFP,;48 pin;LQFP;-40°C to +85°CLead Free
MAX1368ECM+TActiveLQFP;-40°C to +85°CSee data sheet
MAX1368ECM-TNo Longer AvailableMAX1368ECM+LQFP;48 pin-40°C to +85°CSee data sheet
MAX1366-MAX1368.pdf MAX1368
Delta-Sigma ADCs Replace Integrating ADCs for Panel Meters MAX1499
MAX1366-MAX1368.pdf MAX1368