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 |


Step-Down Converters Target Always-On Car Systems

Maxim Integrated Products has announced the ultra-compact, pin-compatible MAX20075 and MAX20076 step-down converters that enable system designers looking to create small and highly efficient 40-V load dump-tolerant applications. The MAX20075 and MAX20076 step-down converters offer low quiescent current (IQ) and feature integrated compensation. This enables minimal external components that can lead up to 50% savings in board space making them well-suited for always-on automotive applications.

According to Maxim Integrated, car customers expect always-on applications to bring them experiences richer and more compelling than ever before. However, car system designers are challenged with having to balance delivering advanced features with meeting size constraints, power-saving features and high efficiency.

The MAX20075 and MAX20076 in peak current mode draw just 3.5 µA in the low power operating mode, which is key to meeting the stringent OEM IQ consumption requirements of 100 µA per module. The converters enable low noise operation via pin-controlled spread spectrum and fixed 2.1 MHz operation to meet CISPR 25 Class 5 EMI compliance. Furthermore, added advantage of the 2.1 MHz operation and internal compensation is that it lowers the solution size and the bill of materials (BOM) compared to a non-synchronous device that operates in the AM band.

The MAX20075 and MAX20076 are available with a low minimum on-time mode operation, which allows the converters to support large input-to-output conversion ratios. For example, Vbatt input to Vout of less than 3 V at 2.1 MHz; this translates to not having to use a secondary supply, which reduces overall BOM cost by $0.30 to incorporate new functions into the design for greater flexibility. The MAX20075 and MAX20076 meet AEC-Q100, are available in a 3 mm x 3 mm TDFN package, and operate over the -40°C to +125°C temperature range.

Maxim Integrated |