MILPITAS, CALIF. Linear Technology Corp. has unwrapped a 24-bit delta-sigma analog-to-digital (A/D) converter with differential inputs and reference in a 10-pin MSOP package that's less than half the size of an SO-8. As a result, the LTC2411 can fit within the shell of a sensor or transducer.
The A/D operates from a single 2.7-volt to 5.5-V supply and consumes 200 microamps during conversion and 3 microamps during auto shutdown for longer battery life in portable instruments.
The differential reference voltage ranges from 0.1 V to Vcc, which allows the converter to operate in ratiometric and remote sensing applications. The part performs transparent offset and full-scale calibration on every conversion to provide 5-ppm total unadjusted error, 0.5-ppm offset error, 4-ppm full-scale error and 4-ppm integral nonlinearity error.
The LTC2411 features a proprietary no-latency architecture that allows its digital filter to settle in a single cycle. The architecture eliminates the need to "throw away" data after the input signal step, as some other high-resolution A/Ds require, LTC said.
The 24-bit A/D also includes an on-chip oscillator, which eliminates the need for external frequency setting components such as crystals or external clock sources.
The fourth-order sync filter rejects line frequencies to 110 decibels and is pin-selectable between 50 or 60 Hz or can be tuned with an external clock input. An external clock feature allows the LTC2411 to output data at up to 15 Hz without affecting accuracy or output at faster rates if resolution is lower. The LTC2411 is available in both commercial and industrial temperature ranges. It's priced from $7.70 in 1,000-piece quantities.
CALL (408) 432-1900
EETInfo No. 609