3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers

 

Part Number	Replacement	Explanation

Description

Create a design and simulate using EE-Sim^® tools:

The MAX1447/MAX1496/MAX1498 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated light-emitting 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. The MAX1496 is a 3.5-digit (±1999 count) device and the MAX1447/MAX1498 are 4.5-digit (±19,999 count) devices.

The MAX1447/MAX1496/MAX1498 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 input, 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 and overrange/underrange detection. The MAX1447 features on-demand enhanced offset calibration for improved offset performance.

The MAX1447/MAX1498 are available in a 32-pin, 7mm x 7mm TQFP package and the MAX1496 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.

MAX1447, MAX1496, MAX1498: Pin Configuration Enlarge+

Key Features

• High Resolution
  • MAX1447/MAX1498: 4.5 Digits (±19,999 Count)
  • MAX1496: 3.5 Digits (±1999 Count)
• Sigma-Delta ADC Architecture
  • No Integrating Capacitors Required
  • No Autozeroing Capacitors Required
  • >100dB of Simultaneous 50Hz and 60Hz Rejection
• 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
• On-Demand Enhanced Offset Calibration (MAX1447)
• Operate from a Single 2.7V to 5.25V Supply
• Low Power (Exclude LED-Driver Current)
  • Maximum 744µA Operating Current (MAX1496)
  • Maximum 960µA Operating Current (MAX1447/MAX1498)
  • Maximum 325µA Shutdown Current
• Multiplexed Common-Cathode LED Drivers
  • Resistor-Programmable Segment 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)

Applications/Uses

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