AD1886AJST Analog Devices Inc, AD1886AJST Datasheet - Page 26

• Manufacturer Part Number: AD1886AJST
• Description: IC CODEC STEREO 16BIT 48LQFP
• Manufacturer: Analog Devices Inc
• Series: SoundMAX®r
• Type: Audio Codec '97r

Specifications of AD1886AJST

• Rohs Status: RoHS non-compliant
• Data Interface: Serial
• Resolution (bits): 16 b
• Number Of Adcs / Dacs: 2 / 2
• Sigma Delta: Yes
• Dynamic Range, Adcs / Dacs (db) Typ: 87 / 90
• Voltage - Supply, Analog: 4.75 V ~ 5.25 V
• Voltage - Supply, Digital: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP

AD1886A
APPLICATION CIRCUITS
CD-ROM CONNECTIONS
Typical CD-ROM drives generate 2 V rms output and require a voltage divider for compatibility with the Codec input (1 V rms range).
The recommended circuit is a group of divide-by-two voltage dividers as shown on Figure 14.
The CD_GND_REF pin is used to cancel differential ground noise from the CD-ROM. For optimal noise cancellation, this section
of the divider should have approximately half the impedance of the Right and Left channel section dividers.
LINE_IN, AUX, AND VIDEO INPUT CONNECTIONS
Most audio sources also generate 2 V rms audio level and require a –6 dB input voltage divider to be compatible with the Codec
inputs. Figure 15 shows the recommended application circuit. For applications requiring EMC compliance, the EMC components
should be configured and selected to provide adequate RF immunity and emissions control.
MICROPHONE CONNECTIONS
The AD1886A contains an internal microphone preamp with 20 dB gain; in most cases a direct microphone connection as shown in
Figure 16 is adequate. If the microphone level is too low, an external preamp can be added as shown in Figure 17. In either case the
microphone bias can be derived from the codec’s internal reference (V
V
To meet the PC99 1.0A requirements, the MIC signal should be placed on the microphone jack tip and the bias on the ring. This
configuration supports electret microphones with three conductor plugs as well as dynamic microphones with two conductor plugs
(ring and sleeve shorted together).
Additional filtering may be required to limit the microphone response to the audio band of interest.
REFOUT
signal can also provide the midpoint bias for the amplifier.
LINE/AUX/VIDEO INPUT
J1
CD ROM AUDIO
HEADER FOR
(LGGR)
1
2
3
4
5
L2 600Z
L1 600Z
1
2
3
4
COMPONENTS
EMC
C1
470pF
C2
470pF
VOLTAGE DIVIDER
4.7k
2.7k
4.7k
R1
R3
R5
VOLTAGE DIVIDER
4.7k
4.7k
R3
R1
R2
4.7k
R4
2.7k
R6
4.7k
R2
4.7k
R4
4.7k
AC-COUPLING
REFOUT
0.33 F
0.33 F
0.33 F
C3
C2
C1
AC-COUPLING
+
+
+
) using a 2.2 kΩ resistor. For the preamp circuit, the
0.33 F
0.33 F
C3
C4
+
+
TO CODEC CD_L INPUT
TO CODEC CD_GND_REF INPUT
TO CODEC CD_R INPUT
TO CODEC RIGHT CHANNEL INPUT
TO CODEC LEFT CHANNEL INPUT