As ubiquitous construction is beginning to take place in utowns that are going to be built in Korea in the near future, one of the factors is to come up with energy saving solutions. Smart cards in cell phones will take a vital role in the ubiquitous life as well, which also require energy saving batteries so that customers in the future will be able to take care of most matters via cell phones without worrying about running out of battery life.
National Semiconductor has been developing their PowerWise brand with this trend in mind. PowerWise refers to products that provide a level of performance at reduced power consumption levels. These products have exceptional performance-to-power ratios and their components can be found in every National Semiconductor product family from op-amps to high-speed data converters, from communication devices to power regulators.
What is the performance-to-power ratio Richard F. Zarr of National Semiconductor puts it this way: "A simple metric for an automobile is the miles per gallon rating. As the cost of gasoline -- our current infrastructure portable energy storage medium -- rises, this metric becomes more important. This is the same concept of the performance- to-power ratio. This can mean two things to an engineer -- lower power consumption and waste heat generated, or higher performance at the same power consumed."
As Zarr further stated in the brand description, the lower power means less dollars are spent on energy and longer battery life. Therefore, PowerWise brand portable music players or mobile phones will provide longer service playtime due to reduced heat wear on the electronics. Semiconductors fatigue in the presence of elevated temperatures. Thus, the lower the ambient temperature, the longer service life a product will provide.
Longer service life of a product means reduced cost of replacement. The increase of performance-to-power ratio allows designers to produce higher performance components that use the same or less energy that can be applied to developed technology products like High-definition Television and Digital Video Recorders. National's PowerWise brand semiconductors are applied in many products and made contributions to high quality technology in the worldwide market.
National Semiconductor has many products with this function. For instance, they recently released the industry's first single-chip 3W mono Class D audio amplifier with spread spectrum technology and an integrated boost converter.
The LM48511 Boomer amplifier, from National's PowerWise energy- efficient product portfolio, joins the recently announced 1.2W LM48510 as the second product in a new family of Boomer Class D audio amplifiers that allow portable products to operate at constant high-level output power even as batteries deplete to lower voltages.
The LM48511 drives an 8-Ohm speaker load at 3W continuous power to enable louder speaker volumes for manufacturers of push-to-talk cell phones, portable global positioning systems (GPS) and MP3 docking stations with portable speakers, as well as a broad range of other battery-powered applications.
The LM48511 uses National's unique spread spectrum technology to lower electromagnetic interference emissions more than 11 dB below the Federal Communications Commission limit. The LM48511's 80 percent efficiency at 5V extends battery life when compared to boosted Class AB amplifiers, and its independent regulator and amplifier shutdown controls also optimize power savings by disabling the regulator when high output power is not required. The device's small footprint reduces printed circuit board size and lowers development costs.
The LM48511 high-efficiency Class D audio power amplifier provides 2.5W to 3W of continuous power into an 8- Ohm speaker when operating from a 3V to 5V power supply with less than 1 percent total harmonic distortion plus noise (THD+N). The gain of the LM48511 is set by external resistors, which allows independent gain control from multiple sources by summing the signals. The LM48511 features a low-power consumption shutdown mode as well as output short-circuit and thermal overload protection. Advanced pop-andclick circuitry eliminates output transients which would otherwise occur during power or shutdown cycles. The amplifier also includes selectable feedback networks that allow the designer to scale power and manage efficiency. Available now in a 24-pin LLP package, the LM48511 is priced at US$1.75 in 1,000-unit quantities.
National Semiconductor Corporation also recently introduced two precision operational amplifiers, or op amps, that offer the industry's lowest input voltage noise and highest accuracy for products operating at low frequencies and low supply voltage. Target applications include industrial and scientific weight scales, pressure sensors and other low ohmic sensor systems.
National's LMP7731 single and LMP7732 dual precision op amps are the latest additions to the company's LMP precision amplifier family and provide low input voltage noise of 2.9 nV/sqrt Hz with a 1/f noise corner of only 3 Hz. They also feature 0 Hz to 10 Hz peak-to-peak noise voltage of 78 nVpp. This ensures highly accurate signal conditioning, while minimizing distortion in low-frequency (near DC) sensor applications. The new LMP precision op amps are built on the company's proprietary VIP50 BiCMOS process technology. The VIP50 process allows National to design higher-performance precision op amps, along with the most power-efficient, low-voltage amplifiers on the market.
Additionally, the precision of the LMP7731 and LMP7732 amplifiers supports data acquisition systems of 16- bits or greater. In these high-resolution data acquisition systems, the designer commonly scales the output of a sensor to the full-scale input of an analog-todigital converter to ensure optimum sensitivity.
The LMP7731 single and LMP7732 dual are low-noise, low offset voltage, rail-to-rail input and output (RRIO), low-voltage precision amplifiers. These op amps feature bipolar input stages with input bias cancellation circuitry that lowers the input current to only 1.5 nA. They provide low DC offset voltage at 40 uV, support a supply voltage range of 1.8V to 5.5V and offer a wide gain bandwidth of 22 MHz while consuming 2 mA of current. This high gain bandwidth along with a high open-loop gain of 130 dB enables accurate signal conditioning in systems with high closed-loop gain requirements.
The LMP7731/32 op amps offer performance exceeding 120 dB for common mode rejection ratio, power supply rejection ratio and large signal voltage gain. With an input offset voltage drift of 1 uV per degrees C, these op amps are able to operate across an extended temperature range of -40 degrees C to 125 degrees C. The LMP7731 and LMP7732 are available in 5-pin SOT23 and 8-pin SOIC packages. Available now and priced in 1,000-unit quantities, the LMP7731 is US$1.15 and the LMP7732 is US$1.80.
National Semiconductor has offices in the United States, Japan, Hong Kong, and Germany. One of its regional design centers is in Seoul, Korea.
National's devices and solutions are expected to collaborate with the Korean IT industry and together bring competitive products to the global market.
