Multi-chip Module for DC-DC Converters Provides Space Savings and High Efficiency

To address the demand for higher current and higher frequency power solutions for dc-dc converters, Toshiba America Electronic Components Inc. (TAEC) with its parent company, Toshiba Corp. (Toshiba) recently announced the company has created a multi-chip module (MCM) that combines a driver IC with a MOSFET and Toshiba MOSBD, a single-die combination of a power MOSFET and a Schottky Barrier Diode, in one compact package to achieve greater power output, higher efficiency, a faster response time and improved precision. Developed by Toshiba, the first of these MCM's in a planned series for dc-dc converter applications is designated TB7001FL. The device features a wide input voltage range, a high operating frequency up to 1 MHz and a small package, making it an ideal for use in applications such as notebook and desktop PCs, servers and high-current point-of-load dc-dc converters.

The device includes a high-side MOSFET, a MOSBD to handle low-side functions in the dc-dc converter, and a driver IC that includes a high speed MOS gate driver and level shifter functions to drive the high-side MOSFET. Built-in functions include low-side MOSBD shutdown input, thermal shutdown and undervoltage protection. The MCM solution minimizes stray inductance because the bonding wires are short, enabling the device to achieve a higher efficiency than would be achieved with comparable discrete solutions. The compact packaging radiates heat from the bottom of the MCM, dissipating it into the printed circuit board. This enables the device to achieve very low thermal resistance of approximately 3°C/W and high efficiency ratings of 84% (at V_IN = 12 V, V_OUT = 1.5 V, I_OUT = 20 A and Fc = 1 MHz). The input voltage for the TB7001FL MCM can be as high as 19 V, and the supply voltage is 5 V; the switching frequency is 1 MHz. The inclusion of the driver IC brings supplementary capabilities to the TB7001FL MCM, including protection features such as the MOSBD shutdown input, thermal shutdown and undervoltage protection.

Toshiba's TB7001FL MCM device is available in an 8-mm × 8-mm × 0.85-mm package that is lead (Pb)-free and RoHS-compatible. Samples of the TB7001FL are available now, priced in sample quantities at $4.50 each.