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PenDown
PenUp
Transitionat
Pen-DownDetection
Transitionat
Pen-DownDetection
ShortPulseIgnoredDueto
Pen-UpDebounceSetting
PenDown
NoBeepIsInitiated
Due ToPen-Up
Debounce TimeSetting
T0203-01
5.6.9
Analog Audio Routing
5.6.9.1 Analog Output Volume Control
5.6.9.2 Headphone Analog Output Volume Control
TSC2117
Low-Power Audio Codec With Embedded miniDSP, Stereo Class-D
Speaker Amplifier, and Smart Four-Wire Touch-Screen Controller
SLAS550A – APRIL 2009 – REVISED JUNE 2009
www.ti.com
Figure 5-36. Automatic Beep Mode With Pen-Up Debounce Enabled
Because the key click function uses the digital signal processing block, the CODEC_CLKIN, DAC, analog
volume control, and output driver must be powered on for the key-click sound to occur.
The TSC2117 has the capability to route the DAC output to either the headphone or the speaker output. If
desirable, both output drivers can be operated at the same time while playing at different volume levels.
The TSC2117 provides various digital routing capabilities, allowing digital mixing or even channel
swapping in the digital domain. All analog outputs other than the selected ones can be powered down for
optimal power consumption.
The output volume control can be used to fine-tune the level of the mixer amplifier signal supplied to the
headphone driver or the speaker driver. This architecture supports separate and concurrent volume levels
for each of the four output drivers. This volume control can also be used as part of the output pop-noise
reduction scheme. This feature is available even if the ADC and DAC are powered down.
For the headphone outputs, the analog volume control has a range from 0 dB to –78 dB in 0.5-dB steps
for most of the useful range plus mute, which is shown in
Table 5-37 and
Table 5-38. This volume control
includes soft-stepping logic. Routing the left-channel DAC output signal to the left-channel analog volume
control is done by writing to page 1/register 35, bit D6. Routing the right-channel DAC output signal to the
right-channel analog volume control is done by writing to page 1/register 35, bit D2.
Changing the left-channel analog volume for the headphone is controlled by writing to page 1/register 36,
bits D6–D0. Changing the right-channel analog volume for the headphone is controlled by writing to
page 1/register 37, bits D6–D0. Routing the signal from the output of the left-channel analog volume
control to the input of the left-channel headphone power amplifier is done by writing to page 1/register 36,
bit D7. Routing the signal from the output of the right-channel analog volume control to the input of the
right-channel headphone power amplifier is done by writing to page 1/register 37, bit D7.
The analog volume-control soft-stepping time is based on the setting in page 0/register 63, bits D1–D0.
APPLICATION INFORMATION
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