
High-voltage, low noise, autozero op amp improves sensor performance
The precision of the MAX44251 improves system accuracy and minimizes errors during signal conditioning. The accuracy over the extended voltage range also makes the op amp more flexible for a range of designs and applications. The MAX44251 provides excellent RF immunity filters that remove the unwanted RF signals often found in industrial and medical applications. Superior efficiency and power savings come with no sacrifice in performance. The low 1.15 mA current consumption per channel offers 10 MHz gain bandwidth and the industry’s lowest noise (5.9 nV/ input referred voltage) for a high-voltage autozero op amp. The MAX44251 is ideally suited for high-voltage applications that require ultra-low noise and ultra-high DC precision, such as interfacing with pressure sensors, strain gauges, precision weight scales, and medical instrumentation.
The MAX44251 has near-zero DC offset and drift through the use of a proprietary autocorrelating, zeroing technique. Autozeroing constantly measures and compensates the input offset, thus eliminating drift over time and temperature and the effect of 1/f noise. The low-input offset voltage of 6µV (max) and voltage temperature drift of 19 nV/°C (max) offer precision across -40 to +125°C. Autozero offset calibration also eliminates the effects of power-supply variations and even common-mode variations.
Along with the lowest noise in its class, the MAX44251 high-speed (10 MHz) autozero op amp adds high-precision capabilities. The device’s power-supply rejection ratio (PSRR), common-mode rejection ratio (CMRR), and large-signal voltage gain (AVOL) exceed 135 dB at +25°C. This accuracy over its wide voltage range increases the flexibility of the design and minimizes the errors during signal conditioning.
Availability and Pricing
The MAX44251 is rated over the -40 to +125°C temperature range and is available in 8-pin SOT23 and µMAX packages. Pricing starts at $1.48 (1000-up, FOB USA).
More information on Maxim’s industrial signal-chain solutions at
www.maxim-ic.com/control-auto
