On April 18, 2014, Micrel Korea (CEO Young Jun Oh, www.micrel.com), a leading industry provider of high-performance analog and high-speed mixed-signal solutions as well as LAN, timing and communications solutions, unveiled the MIC2111 DC/DC multi-mode controller for the first time at APEC (Applied Power Electronics Conference and Exposition) 2014, held from March 16-20 at the Fort Worth Convention Center. The device announced that day is capable of operating in valley current mode and voltage mode configurations, and provides PWM signals necessary to interface with industry-standard DrMOS. Additionally, it can interface with a complete discrete power stage to deliver high-current, low-voltage solutions for demanding high-performance power core rails in the server, communications, and networking markets. Samples are currently available for order (www.micrel.com), and MIC2111 production devices are scheduled to be supplied from Q2 2014. The price is $0.95 based on 1,000-unit quantities.

Brian Hedayati, Vice President of Marketing for Micrel's High-Performance Linear and Power Solutions division, stated, "The MIC2111 is Micrel's first multi-mode controller capable of operating in either valley current or voltage mode configurations. This device not only provides design flexibility to optimize for specific power requirements, but also minimizes the need to use different controllers, eliminating the need for component quality certification and simplifying inventory management." He added, "Additionally, the MIC2111 solves design challenges of delivering high power to low-voltage core power rails in space-constrained environments."

In valley current mode configuration, the MIC2111 is capable of operating at high frequencies (up to 2MHz) even under low duty cycle conditions. This addresses a common problem that often occurs when high-current, low-voltage core power rails connected to FPGAs, ASICs, or processors are derived from a 12V bus supply. High frequency enables wider operating bandwidth, improving load transient response while reducing the amount of output capacitance and inductor size required. As a result, benefits include minimization of board space and cost. Additionally, this device can be configured for voltage mode operation, providing superior integrity for noise-sensitive applications.

To improve performance, the MIC2111 employs remote sensing to enhance output voltage accuracy, which is a critical requirement for low-voltage core rails in high-current applications, as well as differential DCR current sensing for accurate current limiting.

This device offers a variety of features providing unique flexibility and protection capabilities. The MIC2111 provides overcurrent, overvoltage, and undervoltage protection, and is designed to safely start up with a pre-biased output. Additionally, for improved stability, this solution includes Micrel's proprietary bidirectional single-wire fault pin to ensure proper operation of the controller and power stage. Switching frequency, output voltage, temperature rise limit, and soft-start time are all externally adjustable to meet design requirements. Additional features incorporated to meet production conditions include power sequencing with delay and soft-stop operation. The MIC2111 is available in a compact 3mm x 3mm TQFN package and features an operating temperature range from -40°C to +125°C.