MAX9853 Maxim Integrated Products, MAX9853 Datasheet - Page 38

• Manufacturer Part Number: MAX9853
• Description: (MAX9851 / MAX9853) Stereo Audio CODECs
• Manufacturer: Maxim Integrated Products

Stereo Audio CODECs with Microphone, DirectDrive
Headphones, Speaker Amplifiers, or Line Outputs
The MAX9851/MAX9853 include a VIBE digital output
that may be used to control an external vibrator/trans-
ducer, or may be used as a general-purpose output.
The Vibe circuitry module has its own multiplexer to
allow it to operate from either the S1 or S2 digital audio
interface. Set TSEL to 0 (register 0x09, bit B5) to derive
the VIBE output from the primary digital audio interface
right channel. Set TSEL to 1 to derive the VIBE output
from the secondary digital audio interface left or mono-
mixed left and right channels.
When using signal data to drive VIBE, programmable
gain set by TGAIN (register 0x19, bits B7–B4) is used
to make adjustments with 10-bit output resolution. A
digital lowpass filter is used to condition the signal for
use at the VIBE output.
Figure 6. VIBE Output Using Comparator
Figure 7. Transducer/Vibe Functional Diagram
38
S1 RIGHT S2 LEFT+RIGHT
______________________________________________________________________________________
TSEL
INPUT SIGNAL
PGA
-30dB TO +30dB
LOWPASS
FILTER
400Hz
VIBE Output
SQUELCH
LEVEL
5-BIT
The VIBE output signal may be generated using either
a threshold comparison of a rectified signal or by an
oversampled 1-bit DAC conversion of a nonrectified
signal. Set TMUX to 11 (register 0x09, bits B7–B6) to
use the output of the internal sigma-delta converter for
driving the transducer output. Set TMUX to 10 to com-
pare the digital audio signal to a programmable
squelch threshold level and generate an output signal
as shown in Figure 6. When driving an external trans-
ducer use an external lowpass filter as shown in Figure
7. The VIBE signal can be amplified if needed by an
external amplifier. Set TMUX to 00 or 01 to force the
output to a fixed 1 or 0, respectively, when using VIBE
as a general-purpose output. Use a 1kΩ pullup resistor
to DV
drain output.
1-BIT DAC
ƒ
DD
0
1
to achieve a full-scale signal from the open-
TMUX
COMPARATOR
SQUELCH LEVEL
COMPARATOR
OUTPUT SIGNAL
VIBE
10kΩ
DV
DD
TRANSDUCER
VIBE