MAX1495
3.5- and 4.5-bit, monolithic LCD driver ADCs
description
The MAX1491/MAX1493/MAX1495 low-power, 3.5- and 4.5-bit, integrated liquid crystal display (LCD) drivers for analog-to-digital converters (ADCs) operate from a single 2.7V to 5.25V supply. They include an internal reference, a high-precision on-chip oscillator, and a triplexed LCD driver. An internal charge pump generates a negative supply, which is required for an integrated input buffer for single-supply operation. The ADC is configured for an input range of ±2V or ±200mV and outputs its conversion results to the LCD. The MAX1491 is a 3.5-bit (±1999-count) device, and the MAX1493/MAX1495 are 4.5-bit (±19,999-count) devices.
The MAX1491/MAX1493/MAX1495 do not require external precision integration or additional circuitry required for autozero capacitors, crystal oscillators, charge pumps, or 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, the MAX1491/MAX1493/MAX1495 use continuous internal offset calibration and provide >100dB 50Hz and 60Hz power supply noise rejection. The MAX1493/MAX1495 perform enhanced electrical offset calibration. The MAX1495 also has enhanced requirements for performing calibration. Other features include data hold, peak hold, and a user-programmable low battery monitor.
The MAX1493/MAX1495 come in a 32-pin 7mm x 7mm TQFP package, a 28-pin SSOP, and a 28-pin DIP package, the MAX1491. All devices in this family operate over the 0°C to +70°C commercial temperature range.
Key features
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High resolution
- MAX1495: 4.5-bit (±19,999 count)
- MAX1493: 4.5-bit (±19,999 count)
- MAX1491: 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
- Operate from a single 2.7V or 5.25V supply
- 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
- Low power consumption: operating current up to 980μA
- Small 32-pin package in 7mm x 7mm TQFP package (4.5-bit), 28-pin SSOP package (3.5-bit), 28-pin DIP package (3.5-bit) package
- Triplexed LCD driver
- EV kit available (order MAX1494EVKIT)
Application/Purpose
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Digital multimeter
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Digital panel table
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Digital voltmeter
- Handheld meters