Precision op amps are aimed at IoT

December 22, 2014 // By Peter Clarke
On Semiconductor (Phoenix, Arizona) has introduced a family of "zero-drift" low-voltage CMOS precision operational amplifiers, for use as front-end amplifiers and in power management.

The NCS325 and NCS333 are suitable for use in precision applications in industrial, consumer, wireless and the Internet of Things (IoT) where strong stability across wide operating temperature ranges is mandated.

These devices are complemented by the NCV333 automotive-qualified (AEC-Q100 grade 1) op amp offering similar functional performance for power train, braking, electronic power steering, valve controls, fuel pump and fuel injection system applications.

Featuring high DC precision parameters, such as the 10 microvolts maximum input offset voltage at ambient temperature and the 30 nV/°C of offset temperature drift, make these amplifier devices extremely well optimized for low side current sensing and voltage differential measurement on front-end sensor functions. Minimal voltage variations over temperature along with close to zero offset ensure the efficiency of systems exposed to wide operating temperature ranges without the need for complex software calibration algorithms, resulting in a more manageable design and longer product lifespan.

The NCS325 and NCS333 provide rail-to-rail input and output performance and are optimized for low voltage operation of 1.8 to 5.5V, with a best in class quiescent currents of 21-microamps and 17-microamps respectively at 3.3V. The devices operate with a gain bandwidth of 350kHz with ultra-low peak to peak noise down to 1.1-microvolts from 0.1 to 10 Hz.

Simon Keeton, vice president Integrated Circuit Products at On Semiconductor, said these precision op amps offer industry-leading analog performance. "Historically, engineers have preferred to utilize zero drift precision op amps but the traditionally high cost of such solutions has discouraged implementation. With the introduction of this family of amplifiers, we have been able to make precision affordable," he said in a statement.

Pricing and Packaging

The NCS325 is offered in a 3mm by 1.5mm 5-pin TSOP package. It has unit pricing of $0.35 in 3,000 unit quantities. The NCS333 is offered in a 1.5mm by 3mm SOT23-5 package or in a 2mm by 1.25mm SC70-5 and has unit pricing of $0.50, in 3,000