MAX1491/MAX1493/MAX1495 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated liquid crystal display (LCD) 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 triplexed LCD driver. An internal charge pump generates the negative supply needed to power the integrated input buffer for single supply operation. The ADC is configurable for either a ±2V or ±200mV input range and it outputs its conversion results to an LCD. The MAX1491 is a 3.5-digit (±1,999 count) device, and the MAX1493/MAX1495 are 4.5-digit (±19,999 count) devices. The MAX1491/MAX1493/MAX1495 do not require external-precision integrating or auto-zero capacitors, crystals 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 inputs, allowing direct interface with high-impedance signal sources. In addition, the MAX1491/MAX1493/MAX1495 use continuous internal offset calibration, and offer >100dB rejection of 50Hz and 60Hz line noise. The MAX1493/MAX1495 perform enhanced offset calibration at power-up. The MAX1495 also performs enhanced calibration on demand. Other features include data hold and peak hold, and a user programmable low-battery monitor. The MAX1493/MAX1495 come in a 32-pin 7mm x 7mm TQFP package, and the MAX1491 comes in a 16-pin 5mm x 5mm SOIC package.
The MAX1491/MAX1493/MAX1495 family consists of low-power, 3.5- and 4.5-digit analog-to-digital converters (ADCs) featuring integrated liquid crystal display (LCD) drivers. These devices operate from a single 2.7V to 5.25V power supply and include an internal reference, a high-accuracy on-chip oscillator, and a triplexed LCD driver.
Key features of the MAX1491/MAX1493/MAX1495 family include >100dB rejection of 50Hz and 60Hz line noise, selectable input ranges of +2V or +200mV, and continuous internal offset calibration. The devices do not require external precision integrating or auto-zero capacitors, making them suitable for digital panel meters and hand-held multimeters.
| Resolution (MAX1495/MAX1493) | 4.5 Digits (+/-19,999 Count) |
|---|---|
| Resolution (MAX1491) | 3.5 Digits (+/-1,999 Count) |
| Operating Supply Voltage | 2.7V to 5.25V (Single) |
| Input Range Selection | +2V or +200mV |
| Power Supply Rejection (AVpp) | >80dB |
| Operating Temperature Range | 0°C to +70°C |
The maximum operating current is 980uA.
No, they do not require external precision integrating or autozeroing capacitors.
The devices offer >100dB simultaneous rejection of 50Hz and 60Hz line noise.