SLAS653 – FEBRUARY 2010
www.ti.com
5.6.9.1
Headphone Drivers
The TLV320AIC3120 features a mono headphone driver (HPOUT) that can deliver up to 30 mW per
channel, at 3.3-V supply voltage, into a 16-
load. The headphones are used in a single-ended
configuration where an ac-coupling capacitor (dc-blocking) is connected between the device output pins
and the headphones. The headphone driver also supports 32-
and 10-k loads without changing any
control register settings.
The headphone drivers can be configured to optimize the power consumption in the lineout-drive mode by
writing 11 to page 0 / register 44, bits D2–D1.
The output common mode of the headphone/lineout drivers can be programmed to 1.35 V, 1.5 V, 1.65 V,
or 1.8 V by setting page 1 / register 31, bits D4–D3. The common-mode voltage should be set
≤ AVDD/2.
The headphone driver can be powered on by writing to page 1 / register 31, bit D7. The HPOUT output
driver gain can be controlled by writing to page 1 / register 40, bits D6–D3, and it can be muted by writing
to page 1 / register 40, bit D2.
The TLV320AIC3120 has a short-circuit protection feature for the headphone drivers, which is always
enabled to provide protection. The output condition of the headphone driver during short circuit can be
programmed by writing to page 1 / register 31, bit D1. If D1 = 0 when a short circuit is detected, the device
limits the maximum current to the load. If D1 = 1 when a short circuit is detected, the device powers down
the output driver. The default condition for headphones is the current-limiting mode. In case of a short
circuit on either channel, the output is disabled and a status flag is provided as read-only bits on page 1 /
register 31, bit D0. If shutdown mode is enabled, then as soon as the short circuit is detected, page 1 /
register 31, bit D7 (for HPLOUT) clears automatically. Next, the device requires a reset to re-enable the
output stage. Resetting can be done in two ways. First, the device master reset can be used, which
requires either toggling the RESET pin or using the software reset. If master reset is used, it resets all of
the registers. Second, a dedicated headphone power-stage reset can also be used to re-enable the output
stage, and that keeps all of the other device settings. The headphone power stage reset is done by setting
page 1 / register 31, bit D7 for HPLOUT. If the fault condition has been removed, then the device returns
to normal operation. If the fault is still present, then another shutdown occurs. Repeated resetting (more
than three times) is not recommended, as this could lead to overheating.
5.6.9.2
Speaker Drivers
The TLV320AIC3120 has an integrated class-D mono speaker driver (SPKP/SPKM) capable of driving an
8-
or 4- differential load. The speaker driver can be powered directly from the battery supply (2.7 V to
5.5 V) on the SPKVDD pins; however, the voltage (including spike voltage) must be limited below the
absolute-maximum voltage of 6 V.
The speaker driver is capable of supplying 400 mW per channel with a 3.6-V power supply. Through the
use of digital mixing, the device can connect one or both digital audio playback data channels to either
speaker driver; this also allows digital channel swapping if needed.
The class-D speaker driver can be powered on by writing to page 1 / register 32, bit D7. The class-D
output driver gain can be controlled by writing to page 1 / register 42, bits D4–D3, and it can be muted by
writing to page 1 / register 42, bit D2.
The TLV320AIC3120 has a short-circuit protection feature for the speaker drivers that is always enabled
to provide protection. If the output is shorted, the output stage shuts down on the overcurrent condition.
(Current limiting is not an available option for the higher-current speaker-driver output stage.) In case of a
short circuit, the output is disabled and a status flag is provided as a read-only bit on page 1 / register 32,
bit D0.
60
APPLICATION INFORMATION
Copyright 2010, Texas Instruments Incorporated