MAX7129:Low-Noise, 4 1/2 Digit, Single-Chip ADC with Multiplexed LCD Drivers

The Maxim ICL7129A/MAX7129 is a high precision monolithic 4-1/2 digit A/D converter that directly drives a multiplexed liquid crystal display. Using a novel "successive integration" technique, the ICL7129A/MAX7129 has a ±20,000 count resolution on both 2.00000V and 200.00mV ranges. It features high impedance differential inputs, excellent differential linearity, true ratiometric operation and auto polarity. The only external active component required to make precision DVM/DPMs is a reference. The overrange and underrange outputs and the 10:1 range changing input facilitate the design of autoranging systems. The ICL7129A/MAX7129 detects and flags a LOW BATTERY condition and also checks for continuity, giving a visual indication and a logic level output which can be used to generate an audible signal. The MAX7129 has a fullscale accuracy of 0.0005%, resolution of 10µV, zero reading drift of 0.5µV/°C, an input bias of 10pA max, and a rollover error of less than 1 count. Maxim has reduced the noise of the ICL7129A to 3µV—significantly lower than the MAX7129.

Key Features
  • ±19,999 Count Resolution
  • 10pA Max Input Bias Current (MAX7129)
  • 3µV Peak-to-Peak Noise (ICL7129A)
  • Onboard Multiplexed LCD Display Driver 4-1/2 Digits, 4 Decimal Points, 3 Annunciators
  • Instant Continuity Detector
  • Low Battery Detector and Indicator
  • Overrange/Underrange Outputs
  • Precise 10:1 Range Select
  • 10µV Resolution
  • Significantly Improved ESD Protection
  • Monolithic, Low Power CMOS Design
  • Eliminates Need for Compensation Capacitor
ICL7129A, MAX7129: Typical Operating Circuit
ICL7129A, MAX7129: Typical Operating Circuit
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ICL7129A-MAX7129 Data SheetICL7129A-MAX7129.pdf
Part NumberResolution
Data BusDiff/S.E. InputInternal VREF
Unipolar VIN
nominalmaxSee Notes
ICL7129A200007-SegmentDiff. Only-2.82MQFP/44
$11.21 @1k
$8.57 @1k
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX7129C/DNo Longer AvailableDICE SALES,;NA pin;DICE;0°C to +70°CSee data sheet
MAX7129CJLNo Longer AvailablePDIP;0°C to +70°CSee data sheet
MAX7129CPLNo Longer AvailableMAX7129CPL+PDIP(W),;40 pin;835.7 mm²0°C to +70°CNo
MAX7129CPL+ActivePDIP(W),;40 pin;835.7 mm²0°C to +70°CLead Free
MAX7129CQH+DActivePLCC,;44 pin;311.5 mm²0°C to +70°CLead Free
MAX7129CQH+TDActivePLCC,;44 pin;311.5 mm²0°C to +70°CLead Free
MAX7129CQH-DNo Longer AvailableMAX7129CQH+DPLCC,;44 pin;311.5 mm²0°C to +70°CNo
MAX7129CQH-TDNo Longer AvailableMAX7129CQH+TDPLCC;44 pin0°C to +70°CSee data sheet
ICL7129A-MAX7129.pdf MAX7129
ICL7129A-MAX7129.pdf MAX7129