Infineon Single-Package Integrated Switch Significantly Decreases Power Supply Size and Cost
Designers of the dc/dc power supplies used to power most electronic products are faced with increasingly complex technical problems, such as supplying higher power with lower voltage, while at the same time the market demands shorter and shorter design cycles. To solve this dilemma, reduce complexity and save time, designers increasingly rely on integrated solutions for the driver and the power stage of the converter. However, such integrated switch products typically use specialized and costly packaging to achieve the required electrical performance.
Infineons TDA21201 Integrated Switch devices convert a 12 V input into levels of less than 3.5 V to power the variety of components within personal computers, peripherals and other electronic systems. They are capable of meeting demanding performance requirements using industry-standard, high-volume, low-cost packaging. Priced as much as 50 percent less than competitive integrated power-stage solutions, the TDA21201 devices significantly save board space when compared with the separate driver chip and transistors required with other solutions. This results in very high power density, which is a measure of how much power is provided per area unit of measure.
Additional space savings and total bill of materials (BOM) reductions are realized because the TDA21201 does not require the bootstrap circuit necessary with other solutions. This also helps further reduce design effort and provides designers with the greatest degree of flexibility.
The Infineon TDA21201 Integrated Switch combines a gate driver and two OptiMOS® power MOSFET (metal-oxide semiconductor field-effect transistor) switches in a single industry-standard TO220 package that requires only input and output filters and a PWM (pulse-width modulation) controller to create a complete dc/dc voltage converter for applications in which space is a significant constraint and power dissipation is a concern.
The low-cost package types available from Infineon are the surface-mount TO220-7-128 (D2-PAK) and the through-hole TO220-7-3 (straight-lead) and TO220-7-230 (staggered-lead) packages. The D2-PAK package dissipates heat generated by the device directly into the board, while the other two packages allow the heat to be dissipated into the air, an option not available with any competitive device. These heat dissipation capabilities allow better ambient thermal coupling and higher junction temperatures than the custom packages used in competitive devices.
Combining the power MOSFETs and the driver circuit in a single package also virtually eliminates stray inductances between the semiconductor components, resulting in lower switching losses and a more compact design. The packaging density of the TDA21201 driver/MOSFET combination enables higher board densities for multi-phase converters, making it feasible to package a three- or four-phase converter in the space usually required for a two-phase design.
TDA21201 Technical Features
The TDA21201 is highly efficient in its conversion, achieving efficiencies of over 80 percent at a 200 kHz switching frequency for currents of 20 A. It accomplishes this in large part because of the reduced static and dynamic losses made possible by the proprietary OptiMOS technology used in the MOSFETs.
The MOSFETs can handle currents of up to 30 A and have breakdown voltages of 30 V, which allows them to avoid avalanche during turn-off of the HS (high-side) MOSFET. The drive capability of the gate driver allows the TDA21201 to be operated in the frequency range of from 100 kHz to 500 kHz.
Over-temperature protection shuts down both MOSFETs when the temperature is above 150°C. Because the gate driver is thermally well-coupled to the MOSFETs, this function protects both.
Price and Availability
The TDA21201 Integrated Switch is available now in industry-standard TO220-7-128 D2-PAK, TO220-7-3 straight-lead and TO220-7-230 staggered-lead packages. It is priced at $1.50 in 10,000-piece quantities.
Additional information on the TDA21201 family is available at www.infineon.com/dc2dc.
Infineon Technologies AG, Munich, Germany, offers semiconductor and system solutions for applications in the wired and wireless communications markets, for security systems and smartcards, for the automotive and industrial sectors, as well as memory products. With a global presence, Infineon operates in the US from San Jose, CA, in the Asia-Pacific region from Singapore and in Japan from Tokyo. In the fiscal year 2001 (ending September), the company achieved sales of Euro 5.67 billion with about 33,800 employees worldwide. Infineon is listed on the DAX index of the Frankfurt Stock Exchange and on the New York Sock Exchange (ticker symbol: IFX). Further information is available at www.infineon.com.
D I S C L A I M E R
Infineon, OptiMOS and the stylized Infineon Technologies design are registered trademarks and service marks of Infineon Technologies AG. Other product and brand names may be trademarks or registered trademarks of their respective owners.
The single-package integrated switch TDA21201 allows designers of switching power supplies (PCs, notebooks) to reduce system costs by as much as 50 percent and dramatically reduce the space required.Press Picture
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