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AD1884

Table 3. AD1884 Pin Descriptions (Continued)

Mnemonic

Pin No.

I/O

Description

AVDD 3.3 V

25, 38

CAUTION: DO NOT APPLY 5 V TO THESE PINS!

Analog Supply Voltage 3.3 V ONLY.

MIC_BIAS_IN

Note: AVDD supplies should be well regulated and filtered as supply noise degrades

audio performance.

Source Power for Microphone Bias Boost Circuitry.

5.0 V or 3.3 V

Connect this pin to 5.0 V via a low-pass filter. When connected this way the AD1884 is

capable of providing +3.9 V as a mic bias to all of the mic bias pins (except on

Pin 31).

If 5 V is not available, connect this pin to +3.3 V (AVDD) via a low-pass filter.

AVSS

26, 42

The AD1884 produces a mic bias voltage relative to the AVDD supply

(typically 3.0 V @ AVDD = 3.3 V).

Analog Supply Return (Ground). AVSS should be connected to DVSS using a

conductive trace under, or close to, the AD1884.

The symbols used in this table are defined as: I = Input, O = Output, LI = Line Level Input, LO = Line Level Output, HP = Output capable of

driving headphone load, MIC = Input supports microphones with MIC bias and boost amplifier.

Rev. 0

Page 11 of 16

January 2007

AD1884 Datasheet(PDF) 11 Page - Analog Devices