Step-Up Converter suits low noise blocker applications.
Press Release Summary:
Designed for low noise blockers (LNBs) used in set-top boxes and integrated digital televisions, LNBH21 power supply and control IC includes step-up voltage converter that works from single input voltage of between 8 and 15 V. It is typically 94% efficient at 750 mA load and has integrated I2C bus that facilitates control and diagnostics with 22 kHz tone signaling. This provides complete bi-directional interface between LNB and system controlling it.
Original Press Release:
Step-up Converter from STMicroelectronics Simplifies LNB Control for Digital Satellite TVs
Integrated I2C bus eases control and diagnostics
Geneva, September 10, 2004 - STMicroelectronics (NYSE: STM) has introduced a power supply and control IC for the low noise blockers (LNBs) used in set-top boxes and integrated digital televisions.
The LNBH21 includes a step-up voltage converter that works from a single input voltage of between 8V and 15V, simplifying system design. The converter is typically 94% efficient at a 750mA load.
The part also keeps the voltage drop on the internal linear regulator to a typical 2.2V, as compared with the 3.4V of previous models, reducing the power dissipation to 1.1W at 500mA load.
The part has an I2C interface and 22kHz tone signaling to provide a complete bi-directional interface between the LNB and the system that is controlling it. This further simplifies design and makes the part suitable for energy-saving digital set-top box designs.
The fast start-up of the oscillator enables DiSEqC encoding and the integrated tone detector supports bi-directional DiSEqC 2.0 signaling. Two output pins can be used to bypass any output filters, to avoid tone distortion.
The part is compliant with both the Eutelsat and DirecTV output specification and offers digital compensation for cable length.
The part also offers LNB short-circuit and over-temperature protection, with diagnostic bits presented to the I2C interface.
It supports two output currents, of 450mA and 750mA and has an ESD rating of 4KV on the power output pins.
US pricing is 1.25$US in quantities of 1K. Further information is available at www.st.com/vregs
About STMicroelectronics
STMicroelectronics is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2003, the Company's net revenues were $7.24 billion and net earnings were $253 million. Further information on ST can be found at www.st.com.
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