Enpirion
®
Power Evaluation Board User Guide
EN2340QI
PowerSoC
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Foot print is also provided for a SMA connector to S_IN 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.
•
A two pin header footprint is provided for the S_OUT pin. This signal can be used
to synchronize another EN2340 to the switching frequency coming out of the
S_OUT pin.
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The board comes with input decoupling and PVIN (12VIN) reverse polarity
protection to guard the device against common setup mishaps. Please note there
is no reverse polarity protection on AVIN input.
Quick Start Guide
STEP 1:
This board has some additional components on the back side including a
resistor divider from PVIN to Enable to GND (indicated as NR1 & NR2 in the
schematic). As a result of these components, there is no need for a jumper on J3 (see
Figure 1), and the component FB1 (to the left of AVIN test point TP28) should not be
populated. Please contact Altera Power Applications support if your board does not
have these components added on the back side, or if FB1 is still populated.
Figure 1: Enable header without any jumpers
STEP 2:
Connect the 12V nominal Power Supply to the input power connectors, 12VIN
(J7) and GND (J11) as indicated in Figure 4 and set the supply to the desired voltage.
CAUTION
:
Be mindful of the polarity. Even though the evaluation board comes
with reverse polarity protection diodes, it may not protect the device under all
conditions.
STEP 3:
Make sure the two-in header J1 is properly populated depending on how you
want to power AVIN. If you want to use the device in a single input supply mode, and
use the on-chip AVINO pin, then populate J1 with a shorting jumper. If you want to
supply your own external AVIN, then remove the jumper from J1, and connect a 3.3V
nominal power supply to the AVIN (J9) and GND (J11).
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