Multi-mode DC/DC controller delivers up to 50A

March 14, 2014 // By Graham Prophet
Distributor Ismosys will handle Micrel’s DC/DC multi-mode controller, the company’s first multi-mode controller capable of operating in either a valley current or voltage mode configuration.

The MIC2111 controller provides the necessary PWM signal to interface with industry standard DrMOS and with fully discrete power stages to deliver a high current, low voltage solution to high performance power demanding core rails in server, communication, and networking applications. Improved output voltage accuracy - a critical requirement for low voltage core rails in high current applications – is boosted because it uses a differential DCR current sense for an accurate current limit as well as remote sensing.

In a valley current mode configuration, the MIC2111 enables high frequency operation (up to 2 MHz) even under low duty cycle conditions, which resolves a common design challenge when powering high current, low-voltage core power rails associated with FPGAs, ASICs, and processors from a 12V bus supply. The higher frequency enables a wider operating bandwidth, improving the load transient response while reducing the amount of output capacitance and the size of the inductor. The new MIC2111 controller can also be configured in a voltage mode operation, providing for even better immunity in noise sensitive applications.

The MIC2111 offers features to provide flexibility and protection. Its over-current and over- and under-voltage protection is designed to safely start up into a pre-biased output. Additional robustness is provided by Micrel's proprietary bi-directional single wire fault pin that ensures that the controller and power stage are operating properly. The switching frequency, output voltage, thermal limit, and soft-start time can all be adjusted externally to meet specific design requirements. Other factory trimmed optional features include a power-on delay and soft-stop operation.

The MIC2111 will be available in a 3 x 3 mm TQFN package and operates over the -40C to +125C temperature range.