EN6337QI/EN6347QI
Evaluation Board User Guide
Nov 2010
Page 2 of 9
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A jumper is provided for controlling the Enable signal. Enable may also be
controlled using an external switching source by removing the jumper and
applying the enable signal to the ENA clip-on terminal.
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A jumper is also provided to connect the POK pull-up resistor to the input supply.
This jumper is especially useful to measure the disable current and eliminates
having to subtract the current drawn by the POK resistor.
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A jumper is provided for controlling the LLM/SYNC pin. This pin can be high for
automatic LLM (light-load mode) operation. If it is pulled low, the part will be in
PWM mode only.
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Foot print is also provided for a SMA connector to LLM/SYNC input. A switching
input to this pin allows the device clock to be phase locked to an external signal.
This external clock synchronization allows for moving any offending beat
frequency to be moved out-of-band. A swept frequency applied to this pin results
in spread spectrum operation and reduces the peaks in the noise spectrum of
emitted EMI.
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The board comes with input decoupling and reverse polarity protection to guard
the device against common setup mishaps.
