Intermediate Bus Converters Incorporate Digital Control
Tualatin, Ore., U.S.: CUI has released two series of fully regulated intermediate bus dc-dc converters following its licensing of Ericsson’s FRIDA II digitally controlled advanced bus converter portfolio. The NQB and NEB series, part of CUI’s Novum Advanced Power range, are pin-compatible with Ericsson’s BMR456 and BMR457 series, respectively (see the figure).
The quarter-brick NQB and eighth-brick NEB series are based on a 32-bit ARM MCU with power-optimising firmware designed to maximise and flatten the efficiency curve, providing peak performance across a much wider range of loading conditions than other intermediate bus converters.
With typical efficiencies as high as 96.4% and optimised efficiency from 20% to 100% load, the modules suit applications where loading conditions can vary greatly. The firmware is also designed to handle input voltage transients with slew rates of up to 0.5 V/µs, while keeping the output voltage within ±10% and ensuring the output voltage doesn’t trigger over-voltage protection.
The NEB and NQB series both provide a digital interface that complies with PMBus 1.2. A range of parameters can be set via a USER_STORE memory block. A number of protection features can be set, including over-temperature, over-current, and over-voltage.
The converters are available in two input range configurations: 40- to 60-V dc input for datacom applications and 36 to 75 V dc for telecom applications. The NEB eighth-brick series is offered with power ratings ranging from 264 to 300 W, while the NQB quarter-brick series is available in 420- to 468-W configurations.
Output voltage for all models is preset at 12 V dc. For dynamic bus applications, users can dynamically adjust the NEB’s output voltage via PMBus from 6.9 to 13.2 V dc and the NQB’s output voltage from 4.0 to 13.2 V dc. For higher-power requirements, optional Droop Load Sharing is offered in both series.