MAX1447 Low-power, 3.5 and 4.5 digital, analog-to-digital converters (ADCs) operate with integrated light-emitting diode (LED) drivers from a single 2.7V to 5.25V supply.
Key features
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High resolution
- MAX1447/MAX1498: 4.5-bit (±19,999 count)
- MAX1496: 3.5-bit (±1999 count)
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Σ-ΔDC architecture
- There is no integrated capacitor
- There is no auto-zero capacitor
- > 100dB for both 50Hz and 60Hz rejection
- Selectable input range± 200mV or ±2V
- Selectable voltage reference: internal 2.048V or external
- Internal high-precision oscillator eliminates the need for external components
- Automatic offset calibration
- Enhanced Offset Calibration on Demand (MAX1447)
- Operates from a single 2.7V to 5.25V supply
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Low power consumption (excluding LED drive current)
- 744μA Maximum Operating Current (MAX1496)
- 960μA Maximum Operating Current (MAX1447/MAX1498)
- 325μA maximum shutdown current
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Multiplex common cathode LED driver
- Resistor programmable segment current
- Small 32-pin, 7 mm x 7 mm TQFP package (4.5-bit), 28-pin SSOP package (3.5-bit)
- Also available in PDIP package (3.5-bit)
Application/Purpose
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Digital multimeter
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Digital panel table
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Digital voltmeter
- Handheld meters
description
The MAX1447/MAX1496/MAX1498 low-power, 3.5- and 4.5-digital, analog-to-digital converters (ADCs) operate with integrated light-emitting diode (LED) drivers from a single 2.7V to 5.25V supply. They include internal references, a high-precision on-chip oscillator, and a multiplexed LED display driver. An internal charge pump generates a negative supply, which is required for an integrated input buffer that operates from a single supply. The ADC is configured for an input range of ±2V or ±200mV and an LED to output its conversion result. The MAX1496 is a 3.5-bit (±1999 count) device and the MAX1447/MAX1498 is a 4.5-bit (±19,999 count) device.
The MAX1447/MAX1496/MAX1498 do not require external precision integrating capacitors, autozero capacitors, crystal oscillators, charge pumps, or other circuitry required for dual-slope ADCs commonly used in panel instrumentation circuits.
The devices also feature on-chip buffers, differential signals, and reference inputs that allow direct interfacing with high impedance signal sources. In addition, they use continuous internal offset calibration and provide 100 dB rejection at 50Hz and 60Hz power supply noise. Other features include data hold, peak detection, and overrange/underrange detection. The MAX1447 features enhanced offset offset performance improvements.
The MAX1447/MAX1498 are available in 32-pin packages, and the MAX1496 in the 7mm x 7mm TQFP package is available in 28-pin SSOP and 28-pin PDIP packages. All devices in this family operate over the extended temperature range of -40°C to +85°C.