CS5509-AS datasheet(16/23 Pages) CIRRUS

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CS5509

DS125F2

Power Supplies and Grounding

The analog and digital supply pins to the CS5509

are brought out on separate pins to minimize noise

coupling between the analog and digital sections of

the chip. In the digital section of the chip the supply

current flows into the VD+ pin and out of the GND

pin. As a CMOS device, the CS5509 requires that

the supply voltage on the VA+ pin always be more

positive than the voltage on any other pin of the de-

vice. If this requirement is not met, the device can

latch-up or be damaged. In all circumstances the

VA+ voltage must remain more positive than the

VD+ or GND pins; VD+ must remain more posi-

tive than the GND pin.

Figure 9a illustrates the System Connection Dia-

gram for the CS5509. Note that all supply pins are

bypassed with 0.1 µF capacitors and that the VD+

digital supply is derived from the VA+ supply. Fig-

ure 9b illustrates the CS5509 operating from a +5V

analog supply and +3.3V digital supply.

When using separate supplies for VA+ and VD+,

VA+ must be established first. VD+ should never

become more positive than VA+ under any operat-

ing condition. Remember to investigate transient

power-up conditions, when one power supply may

have a faster rise time.

CS5509-AS 数据表(PDF) 16 Page - Cirrus Logic