The MAX1491/MAX1493/MAX1495 do not require external-precision integrating or auto-zero 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 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.