Longest Cold Plate Announced at PCIM

May 23, 2007 by Jeff Shepard

TAT Technologies, a first-time exhibitor at PCIM Europe, introduced the "longest cold plate of is kind" today. In addition to this unusual announcement from TAT, Mitsubishi Electric Europe B.V. announced a new 1,200V IGBT and a new integrated power module (IPM) and Zetex Semiconductors debuted a high-power LED driver IC.

As example of the company’s unique capabilities, TAT presented a light-weight 1.90 meter-long, liquid-cooled cold plate for an airborne pod system. "This cold-plate was manufactured in a vacuum-brazing process, which makes it extremely robust and designed for us in harsh environments," said Oliver Kittan from TAT. "It’s plate and fin technology provides an extremely high thermal performance. It is only 6.5mm thick but 1.9 meters long and is probably the longest cold plate of its kind," Kittan concluded.

This unusual cold plate uses paraffin-wax functioning as a phase change material. This provides additional cooling capacity during times of high heat load, such as when a military jet is flying very fast at low altitude and the ambient air is too hot for cooling due to the aircraft’s surface friction.

Targeting more earth-bound applications, Mitsubishi added a medium-frequency 1,200V IGBT targeted at applications such as medical equipment, induction heating, welding equipment and other resonant power circuits. The new NFM series IGBTs combines 5th generation CSTBT™ (Carrier Stored Trench Bipolar Transistor) chip technology with a LPT (Light Punch Through) wafer and features a fast switching capability without increasing the on-state drop.

Available in current ratings of 100A for a single device up to 600A dual devices, the NFM series is optimized for 30kHz switching and features high-speed turn-off characteristics without increasing losses by maintaining a typical saturation voltage of 3.0V at rated collector current and a junction temperature of 125°C.

Mitsubishi also introduced the M81500FP, a single-chip 90W inverter for BLDC drives in white good applications. The new device is rated for 500V and 1A and integrates control, drive and protection functions as well as IGBTs free-wheeling diodes and bootstrap diodes.

"Up to now manufacturers of dish washers, compressors for refrigerators or small pumps for heating systems had to refrain from sing electronic motor control due to space and cost restraints," claimed Van Trung Nguyen, General Manager Power Semiconductors Europe at Mitsubishi. "Compared to a discrete solution using DPAK transistors and SO8 high-voltage ICs, the new M81500FP reduces the PCB space required by 55% to less than 210 square millimeters and it reduces the overall system cost in a way that brushless dc motors can now be used in the non-premium segments of white goods," Nguyen concluded.

Operating from a 6 to 60V input supply and achieving up to 95% efficiency, the ZXLD1362 from Zetex can drive p to 16 high-power LEDs with an adjustable output current of up to 1A. Provided in a TSOT23-5 package, this LED driver is claimed to be the smallest of its kind with a 1A rating.

Output current can be adjusted using either pwm or dc voltage control signals to the adjust pin. Supporting an operating frequency up to 1 MHz, this device is able to offer highly-sensitive and accurate LED brightness control, with a typical dimming ratio of 1000 to 1 cited at 300kHz.

Integrating a 60V MOSFET switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal output current, this chip enables high-power LEDs to benefit from ground referenced return path, of particular importance in architectural lighting applications.