Nujira releases DC/DC converter reference design

Engineered for use with the company's Coolteq.h power modulator modules, the Nujira Coolteq.p DC/DC converter reference design is typically suitable for up to 40W RRH and BTS applications.

Coolteq.h modules do not require a highly regulated supply and Coolteq.p was developed specifically to address the opportunity to use a lower-cost, high-efficiency, lightly regulated supply to power the radio-frequency (RF) subsystem.

Features of Coolteq.p include a 3.3V input terminal for logic circuit supply pass-through and ample reserve power to allow other system components such as RF drivers, pre-drivers or whole RRH to be supplied via appropriate low-power regulators.

According to Nujira, Coolteq.p can be manufactured for around USD15 (GBP9.40).

Jeremy Hendy, the company's vice-president of sales and marketing, said: 'Unlike traditional analogue PA designs, our Coolteq.h modules don't need an expensive, highly regulated power supply to meet the stringent adjacent channel noise specifications.

'Our DC/DC converter reference design demonstrates the wider system benefits that Nujira's Coolteq envelope tracking products bring to designers of 3G and 4G remote radio heads.

/By removing the need for a highly regulated power supply, our Coolteq.p reference design can operate at 95 per cent efficiency, which is equivalent to adding three to five percentage points to the efficiency of the PA output stage,' he added.

Coolteq.p operates from a -39V to -60V supply and offers +24V and +48V unregulated outputs.

It can support a total load of 180W, which gives 30W reserve power when used with a Coolteq.h module driven at full power.

The efficiency of the converter is 95 per cent at full power, dropping to 93 per cent at 50W.

The design offers short- and open-circuit protection at the input and the output, with an automatic restart within 150ms of the triggering event being cleared.

The input and output sections of the design feature 500V isolation.

The Coolteq.p design includes an enable/isable line to allow the subsystem to be powered down remotely.

Its footprint is 62 x 53mm.