Datasheet

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TYPICAL CIRCUIT CONNECTION
R1 R2
654321
87
26
25
32
31
30
29
28
27
9
10
11
12
13
14
15
16
1718
192021222324
POWER MBIAS
BGND
TEST1
TEST0
SSPND
MMUTE
REC
PLAY
PGND
PCM2912
FL
FR
V
COM 1
V
COM 2
AGND
N.C.
V
CCA
V
IN
X1
C2
R4
V
BUS
D – D+ GND
USBConnector
C3
C1
Microphone
Headphone
PLAY
REC.
MicMute
R8
R9
C17
C14
C15
R6
C12
R7
C4
C5
C11
R10
R11
R12
R13
C6
C7
C8
C9
C10
C13
C16
R5
R3
V
CCP
MAMP
V R
OUT
V
CCR
HGND
V
CC
L
V L
OUT
V
BUS
D-
D+
V
D
D
DGND
XTO
XTI
C18
L1
PCM2912
SLES216 – FEBRUARY 2008
A bus-powered (Hi-power), +20-dB microphone amplifier application example follows.
NOTE: X
1
: 6-MHz crystal resonator
C
1
, C
8
, C
11
, C
14
, C
17
, C
18
: 1 µ F ceramic
C
2
, C
3
: 10 pF to 33 pF (depending on load capacitance of crystal resonator)
C
4
, C
5
: 100 pF ceramic
C
6
, C
10
: 3.3 µ F
C
7
: 0.1 µ F
C
9
: 0.22 µ F electrolytic (depending on required frequency response for microphone input)
C
12
, C
15
: 0.022 µ F ceramic
C
13
, C
16
: 100 µ F electrolytic (depending on required frequency response for headphone output)
R
1
, R
2
: 22 Ω to 33 Ω
R
3
: 1.5 k Ω
R
4
: 1 M Ω
R
5
: 1 k Ω (depending on microphone characteristic)
R
6
, R
9
: 16 Ω
R
7
, R
8
, R
10
, R
11
: 3.3 k Ω
R
12
, R
13
: 820 Ω (depending on LED drive current)
L
1
: 1 µ H (DC resistance <0.6 Ω )
It is possible to change maximum power, if total power of actual application does not require over 100 mA (POWER =
Low to configure as low-power device).
Figure 37. USB Headset Application
NOTE:
The preceding circuit is for information only. Total board design should be considered
in order to meet the USB specification as a USB-compliant product.
26 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): PCM2912