Digital temperature sensors deliver precise measurement

Maxim Integrated Products, Inc. has introduced two digital temperature sensors, designed for cold-chain pharma and other temperature-sensing applications. The MAX31889 digital temperature sensor IC offers a combination of accuracy and power consumption, which can replace expensive resistance temperature detectors (RTDs) in precise temperature-sensitive applications. The MAX31825 digital temperature sensor IC enables up to 64 devices per bus, all parasitically powered by the 1-Wire bus, to reduce wiring complexity.

The MAX31889, claiming the highest accuracy at the lowest power consumption, targets pharmaceutical cold chains, medical monitors and industrial automation applications. These applications call for accuracy, low power, and design simplicity, said the company.

The MAX31889, in a 6-pin µDFN package, provides precision measurement of ±0.25-degree C accuracy across a wide temperature range. The device measures cold-chain pharma product temperatures at a fraction of the cost of RTDs and at 35 percent the power consumed by competitive solutions, Maxim Integrated said.

The MAX31825 temperature sensor targets sensitive processes and applications that often require connecting multiple devices in a space-constrained system to measure temperature and protect processes, assets, and equipment from unacceptable variation, said the company.

While competitive solutions offer the ability to connect up to eight devices and require an additional wire for power, according to Maxim Integrated, the MAX31825 reduces design and wiring complexity by allowing up to 64 devices, all connected to the same parasitically powered 1-Wire bus, with the precision of ±1-degree C accuracy. The 1-wire bus is said to deliver an 8× reduction in wiring compared to competitive two- or three-wire solutions.

The MAX31825, in a 6-bump WLP, provides a low standby current of 2.5 µA , suitable for consumer devices and factory automation, by delivering longer battery life and extending operational uptime. Each device has a unique code which can be optionally programmed with a location address, simplifying system design, said Maxim.

The MAX31889 and MAX31825 temperature sensors, available at Maxim Integrated’s website, are priced at $1.65 and $1.55 (1000-up, FOB USA), respectively. The devices also are available from Maxim’s authorized distributors. The MAX31889EVSYS# and MAX31825EVSYS1# evaluation kits are both priced at $56.