CS4239 Datasheet, PDF (91/98 Pages) Cirrus Logic – CrystalClear™ Portable ISA Audio System

CS4239
CrystalClear^TM Portable ISA Audio System
Power Supplies
VA - Analog Supply Voltage
Supply to the analog section of the codec.
AGND - Analog Ground
Ground reference to the analog section of the codec. This pin should be placed on an analog
ground pin separate from other chip grounds.
VD1 - ISA Digital Supply Voltage
Digital supply for the parallel data bus pins. This pin can be connected to either 3.3 V or 5 V
power supply. When connected to a 3.3 V supply, all ISA bus pins must also be at 3.3 V.
DGND1 - ISA Digital Ground
Digital ground reference for the parallel data bus pins. These pins are isolated from the other
grounds and should be connected to the digital ground section of the board (see Figure 25).
VDF1, VDF2, VDF3 - Digital Filtered Supply Voltage
Digital supply for the internal digital section of the codec (except for the parallel data bus).
These pins should be filtered, using a ferrite bead, from VD1.
SGND1, SGND2, SGND3, SGND4 - Internal Digital Ground
Ground reference for the internal digital section of the codec. Optimum layout is achieved by
placing SGND1/2/3/4 on the digital ground plane with the DGND pin as shown in Figure 25.
DS253PP2
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