Step-Down Converters Save Energy and Space in IoT Devices

STMicroelectronics has announced its ST1PS01 step-down converters. The devices are engineered for small size, low quiescent current and high efficiency at all values of load current, to save energy and real-estate in keep-alive point-of-load supplies and IoT devices such as asset trackers, wearables, smart sensors and smart meters.

Leveraging synchronous rectification, efficiency is 92% at 400 mA full load and 95% when delivering just 1 mA. Power-saving design features keep the quiescent current to a miserly 500 nA and include a low-power voltage reference. There is also a pulse-frequency counter for controlling converter current at light load, with two high-speed comparators to help minimize output ripple.
Integrated feedback-loop compensation, soft-start circuitry and power switches ensure a space-saving solution that requires just a few small-outline passives to complete the circuit. The typical inductor value is 2.2 µH. In addition, output-voltage selection logic not only saves external voltage-setting components but also gives flexibility to configure modules digitally at manufacture or let the host system change the output voltage on the fly. Eight variants, each with four optional output-voltage settings, allow a choice of regulated outputs from 3.3 V to 0.62 5V. All models feature a Power-good indicator.

A wide input-voltage range, from 1.8 V to 5.5 V, further enhances flexibility for designers by allowing various battery chemistries or configurations as simple as a single lithium cell and extending runtime as the battery discharges. ST1PS01 regulators are also ideal for devices powered from energy-harvesting systems and feature a low noise-architecture that allows use in noise-sensitive applications.

An evaluation board, STEVAL-1PS01EJR, helps developers quickly understand how to take advantage of the ST1PS01’s high energy efficiency and feature integration.

ST1PS01 regulators are now in full production, packaged as 400 µm-pitch flip-chip devices measuring just 1.11 mm x 1.41 mm, and priced from $0.686 for orders of 1, 000 pieces.

STMicroelectronics | www.st.com

 

4 mA Integrated Sensor Transmitter Boasts Small Footprint

Maxim Integrated Products has announced the MAX12900, an ultra-low power, highly integrated 4 mA to  20 mA sensor transmitter. Embedded system developers can use it to create small, low power and highly accurate designs for industrial automation system. Ideal applications include industrial automation and process control, loop-powered 4 mA to 20 mA current transmitters, remote instrumentation and smart sensors.

Today’s system designers must develop enhanced 4 mA to 20 mA sensor transmitters with several considerations in mind. These include improved measurement accuracy over a wide temperature range and reduced size to fit in a small enclosure. In addition, they are required to meet a tight current budget of their overall sensor transmitter system as low as 4 mA.

The MAX12900 increases system accuracy with 10 ppm / degrees C voltage reference for up to 3.5x lower drift compared to traditional solutions. The small footprint (5 mm x 5 mm package size) of the MAX12900 integrates 10 optimized building blocks that results in a significant space savings of 20%-50% vs. traditional 4 mA to 20 mA sensor transmitter implementations.

The addition of an integrated high voltage LDO and power sequencing capability simplifies the power up of the 4 mA to 20 mA sensor transmitter. Its reduced current consumption for low power requires just 250 µA of current maximum, enabling up to 50% power savings compared to traditional solutions. The new MAX12900 solution reduces implementation complexity, generating system cost savings by converting pulse width modulation data from a microcontroller into current over a 4 mA to 20 mA loop with two, three, or four wire configurations. The MAX12900 is available in a 32-pin TQFN package and operates over a wide industrial temperature range of -40℃ to +125℃.

The MAX12900 is available at Maxim’s website and select authorized distributors for $2.89 (1000+.) The MAX12900EVKIT# evaluation kit is available for $55

Maxim Integrated | www.maximintegrated.com