National Semiconductor introduced the industry's most powerful boost regulators in a tiny package. The two products set a new standard for power density by combining current-mode control, sub-miniature packaging and high switching frequency. This new standard in power density is made possible by National's Analog Bipolar CMOS DMOS (ABCD)150 process, the fundamental element in National's new family of high-frequency SOT-23 regulators.
These easy-to-use regulators enable a high-performance 3 W step-up converter in a PCB area of less than 0.8 cm2 to meet the power needs of digital cameras, cell phones, PCMCIA and USB peripherals and DSL modems. The first two converters of the family, LM2731 and LM2733, operate at 600 kHz or 1.6 MHz switching frequency, are housed in a SOT23, 5-pin package and utilize current-mode control for superior load and line regulation. The LM2731 has a 22 V, 1.5 A switch, and the LM2733 has a 1 A, 40 V switch.
Cell phone vendors are differentiating their products by adding digital cameras; consumers want the new camera feature in the same form factor without added bulk. The LM2731 is the ideal part to power the flash in the limited area available for the latest generation of cameras.
Many line-powered systems distribute 3.3 V and 5 V, but need 12 V, 15 V, etc. generated at the point of load. The LM2731/33 family provides a tiny and high-performance solution to this common problem.
USB and PCMCIA devices get 4.5-5 V from the host but often need 5 V or 12 V. Some Lithium-Ion powered systems such as cell phones and digital cameras use four or more white LEDs to illuminate a color LCD display. The LM2731 provides the power necessary for these applications without the audible and electrical noise associated with variable frequency solutions.
Key features of National's LM2731 and LM2733 high frequency boost regulators include:
- Easy to use SOT23-5 package, combined with a 1.6 MHz clock and minimal external components, results in the world's highest power density.
- Current mode allows stable operation over a wider input voltage range.
- Pulse-Width Modulation (PWM) provides a predictable, easily filtered switching frequency.
- The LM2731 has a 22 V, 1.5 A switch and is optimized for low input voltages.
- The LM2733 has a 40 V, 1 A switch and is optimized for high output voltages.
- Both parts operate from a 2.7 V to 14 V input and are available in 600 kHz or 1.6 MHz versions.
Availability and Pricing
National Semiconductor's LM2731 and LM2733 boost regulators are available for shipment now. The two devices are priced at $1.08 each in 1,000 quantities.
