Datasheet

TLV320AIC3204
www.ti.com SLOS602B –SEPTEMBER 2008–REVISED OCTOBER 2012
• Mute function
• Automatic gain control (AGC)
• Built in microphone bias
• Stereo digital microphone interface
• Channel-to-channel phase adjustment
• Fast charge of ac-coupling capacitors
• Anti thump
Analog Low Power Bypass
The TLV320AIC3204 offers two analog-bypass modes. In either of the modes, an analog input signal can be
routed from an analog input pin to an amplifier driving an analog output pin. Neither the ADC nor the DAC
resources are required for such operation; this configuration supports low-power operation during analog-bypass
mode.
In analog low-power bypass mode, line-level signals can be routed directly from the analog inputs IN1_L to the
left headphone amplifier (HPL) and IN1_R to HPR.
ADC Bypass Using Mixer Amplifiers
In addition to the analog low-power bypass mode, another bypass mode uses the programmable gain amplifiers
of the input stage in conjunction with a mixer amplifier. With this mode, microphone-level signals can be amplified
and routed to the line or headphone outputs, fully bypassing the ADC and DAC.
To enable this mode, the mixer amplifiers are powered on via software command.
Headphone Outputs
The stereo headphone drivers on pins HPL and HPR can drive loads with impedances down to 16Ω in single-
ended AC-coupled headphone configurations, or loads down to 32Ω in differential mode, where a speaker is
connected between HPL and HPR. In single-ended drive configuration these drivers can drive up to 15mW
power into each headphone channel while operating from 1.8V analog supplies. While running from the AV
DD
supply, the output common-mode of the headphone driver is set by the common-mode setting of analog inputs in
Page 1, Register 10, Bit D6, to allow maximum utilization of the analog supply range while simultaneously
providing a higher output-voltage swing. In cases when higher output-voltage swing is required, the headphone
amplifiers can run directly from the higher supply voltage on LDOIN input (up to 3.6V). To use the higher supply
voltage for higher output signal swing, the output common-mode can be adjusted to either 1.25V, 1.5V or 1.65V
by configuring Page 1, Register 10, Bits D5-D4. When the common-mode voltage is configured at 1.65V and
LDOIN supply is 3.3V, the headphones can each deliver up to 40mW power into a 16Ω load.
The headphone drivers are capable of driving a mixed combination of DAC signal, left and right ADC PGA signal
and line-bypass from analog input IN1L and IN1R by configuring Page 1, Register 12 and Page 1, Register 13
respectively. The ADC PGA signals can be attenuated up to 30dB before routing to headphone drivers by
configuring Page 1, Register 24 and Page 1, Register 25. The analog line-input signals can be attenuated up to
72dB before routing by configuring Page 1, Register 22 and 23. The level of the DAC signal can be controlled
using the digital volume control of the DAC in Page 0, Reg 65 and 66. To control the output-voltage swing of
headphone drivers, the digital volume control provides a range of –6.0dB to +29.0dB
(6)
in steps of 1dB. These
can be configured by programming Page 1, Register 16 and 17. These level controls are not meant to be used
as dynamic volume control, but to set output levels during initial device configuration. Refer to for
recommendations for using headphone volume control for achieving 0dB gain through the DAC channel with
various configurations.
Line Outputs
The stereo line level drivers on LOL and LOR pins can drive a wide range of line level resistive impedances in
the range of 600Ω to 10kΩ. The output common modes of line level drivers can be configured to equal either the
analog input common-mode setting or to 1.65V. With output common-mode setting of 1.65V and DRVdd_HP
supply at 3.3V the line-level drivers can drive up to 1Vrms output signal. The line-level drivers can drive out a
mixed combination of DAC signal and attenuated ADC PGA signal. Signal mixing is register-programmable.
(6) If the device must be placed into 'mute' from the –6.0dB setting, set the device at a gain of –5.0dB first, then place the device into mute.
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