Bus converters

Artesyn Technologies claims to be the first to launch an eighth-brick intermediate bus converter with a 300 W output.

The IBC25A fixed ratio DC transformer model generates an isolated, unregulated 12 V/25 A output with a full load efficiency of 96% and a power density of more than 22 W/cm3 (362 W/in3).

In addition, the company is introducing two eighth-brick IBCs with semi-regulated outputs, featuring input voltage ranges optimised for telecom and computing applications.

The eighth-brick IBCs are intended primarily for powering multiple downstream non-isolated point-of-load converters in distributed power systems with 12 V intermediate bus architectures, where they are suitable low-cost replacements for standard quarter- and half-brick DC/DC converters.

Forming the latest additions to Artesyn's Typhoon family of board-mount DC/DC converters, these second-generation IBCs are targeted at the telecommunications, networking, computing and industrial electronics markets.

The fixed ratio model has an input range of 42 to 53 VDC, generates an isolated, unregulated 12 V output, and is capable of delivering up to 25 A. Line regulation is specified at +10 and -12.5% over the range of input voltages, and load regulation is maintained to within ±1.5% for all load currents within the range 0 to 25 A.

The semi-regulated eighth-brick IBCs are available with a 36 to 75 VDC input for telecom applications, and a narrower 48 VDC ±10% input for datacom applications that do not have a well regulated card supply voltage.

These IBCs are suitable for ultra high performance, narrow input POL converters, which require more tightly controlled supply voltages than their wide input counterparts.

Both models generate an isolated 12 VDC output; the wide input version can deliver up to 17 A of output, while the narrow input version has 20 A.

The narrow input semi-regulated IBC has a setpoint accuracy of ±0.25% and maintains line and load regulation to within ±0.3% and ±1.5%. The wide input version IBC also has a setpoint accuracy of ±0.25% but maintains line and load regulation to within ±1.0% and ±1.5%.

All three eighth-brick IBCs use a full bridge conversion with a primary side microprocessor supervising the PWM controller to maximise performance.

The topology also employs a 'driven synchronous system', in which all power switches are directly controlled by the PWM controller.

All three IBCs also feature a distributed power train, using two power cores instead of one, which increases overall efficiency and improves thermal management and reliability by dispersing heat evenly across the entire module.

Designed for fully automated assembly to help reduce manufacturing costs, the modules are constructed entirely from surface-mount components, using planar in-the-board transformer structures to minimise profile. They have an installed height of 10 mm.