Power supply circuitry, Grounding and power supply decoupling, Analog output filtering – Cirrus Logic CDB4349 User Manual
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DS782DB1
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CDB4349
6. POWER SUPPLY CIRCUITRY
Power is supplied to the evaluation board by three binding posts (GND, +12V, and -12V), as shown in
The ‘+12V’ and ‘-12V’ terminals supply the active output filters. The +3.3 V and +5.0 V circuitry is powered by reg-
ulators fed by the ‘+12V’ terminal. Headers J3, J4, and J7 allow the user to either select +3.3 V or +5.0 V supplies
for the various CS4349 voltage supply pins. Alternatively, the user can remove the shunts on J3, J4, and J7, and
provide an external power supply.
WARNING: Refer to the CS4349 datasheet for maximum allowable voltage levels. Operation outside of this range
can cause permanent damage to the device.
7. GROUNDING AND POWER SUPPLY DECOUPLING
As with any high-performance converter, the CS4349 requires careful attention to power supply and grounding ar-
rangements in order to optimize performance.
details the connections to the CS4349 while
, and
show the component placement and top and bottom layout. The decoupling capacitors are located as
close to the CS4349 as possible. Extensive use of ground plane fill in the evaluation board yields large reductions
in radiated noise.
8. ANALOG OUTPUT FILTERING
The passive output filter on the CDB4349 has been designed according to the CS4349 datasheet.