Advanced Planar Technology Power Modules

St. Neots, United Kingdom 26th June 2009 Pulse Electronics has launched a new family of mil-spec, low-voltage power modules. Called Cheetah II, the family debuts with output powers of up to 150W; but with 200W expected to be available later in the year. Standard input voltages will be 28 and 48V; and outputs can be single, dual or triple with voltages of 12, 15 and 24V available in the debut modules. The full range is expected to span from 3.3 to 48V (output). Unlike other power modules, which tend to be just enclosed DC-DC power boards, Pulse Electronics Cheetah II family members also include input conditioning boards. Here, the conditioning includes differential and common-mode filtering, input current limiting, input reverse protection and transient ride-through. This last feature has given the Cheetah II modules a wide (input) dynamic range: from 15 to 120V.

Alarm signals, all of which are opto-coupled, included in the new modules are: Output Voltage Good, Input Voltage Good and Over-temperature. David Blofield, Pulse Electronics Sales & Marketing Manager, comments: The Cheetah II low-voltage power modules are probably the most advanced, high-reliability mil-spec modules on the market, and they have very small footprints considering their output power – and the fact that conditioning and alarm circuitry is also included within the volume.

The modules feature Pulse Electronics Planar Technology, which sees transformers formed within the layers of the PCB – as opposed to having traditional wound components fixed to the circuit board. The benefits of Planar include improved EMC characteristics, reduced PCB sky-line and greater tolerance to physical shock and vibration.

Each module in the range weighs less than 100g. In a standard [internal] configuration, in which the conditioning circuitry board is located above the power board, a module has a quarter-size PCB footprint; measuring 40(W) x 20(H) x 70mm(D).

However, in applications where a low profile is required, the conditioning and power boards can be placed side-by-side: which lowers the height to around 10mm (whilst increasing the modules width to about 80mm. Blofield adds: Advice on structural configurations and topography is available from Pulse.

The modules have passed MIL-STD-461E (EMC) for aircraft use and environmental test passes include shock, vibration and acceleration to MIL-STD-810E. Typical operating temperatures range from -40 to 70oC, though thermal protection can be provided for up to 115oC at the base plate.

Blofield concludes: Whilst targeted at aerospace and defence applications, the Cheetah II modules are also suitable for other embedded applications – including medical and telecommunications – in fact, anywhere where efficiency and reliability are of paramount importance.

In addition, a module evaluation card is available that can accept any Cheetah II low voltage module plus hold-up capacitors (if required). Input and output voltages, plus alarm signals, are brought to D-type edge-connectors.