SI9140 Datasheet, PDF (1/15 Pages) Vishay Siliconix – SMP Controller For High Performance Process Power Supplies

Si9140
Vishay Siliconix
SMP Controller For High Performance Process Power Supplies
FEATURES
• Runs on 3.3- or 5-V Supplies
• Adjustable, High Precision Output Voltage
• High Frequency Operation (>1 MHz)
• High Efficiency Synchronous Switching
• Full Set of Protection Circuitry
• 2000-V ESD Rating (Si9140CQ/DQ)
DESCRIPTION
Siliconix’ Si9140 Buck converter IC is a high-performance,
surface-mount switchmode controller made to power the new
generation of low-voltage, high-performance micro-
processors. The Si9140 has an input voltage range of 3 to
6.5 V to simplify power supply designs in desktop PCs. Its
high-frequency switching capability and wide bandwidth
feedback loop provide tight, absolute static and transient load
regulation. Circuits using the Si9140 can be implemented with
low-profile, inexpensive inductors, and will dramatically
minimize power supply output and processor decoupling
capacitance. The Si9140 is designed to meet the stringent
regulation requirements of new and future high-frequency
microprocessors, while improving the overall efficiency in new
“green” systems.
Today’s state-of-the-art microprocessors run at frequencies
over 100 MHz. Processor clock speeds are going up and so
are current requirements, but operating voltages are going
down. These simultaneous changes have made dedicated,
high-frequency, point-of-use buck converters an essential part
of any system design. These point-of-use converters must
operate at higher frequencies and provide wider feedback
bandwidths than existing converters, which typically operate
at less than 250 kHz and have feedback bandwidths of less
than 50 kHz. The Si9140’s 100-kHz feedback loop bandwidth
ensures a minimum improvement of one-half the required
output/decoupling capacitance, resulting in a tremendous
reduction in board size and cost of implementation.
With the microprocessing power of any PC representing an
investment of hundreds of dollars, designers need to ensure
that the reliable operation of the processor will not be affected
by the power supply. The Si9140 provides this assurance. A
demo board, the Si9140DB, is available.
APPLICATION CIRCUIT
FaxBack 408-970-5600, request 70026
www.siliconix.com
S-58034—Rev. G, 15-Mar-99
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