
1
FEATURES
DESCRIPTION
APPLICATIONS
FMTuner
Codec
(MP3)
TPA2050D4
StereoClass-D
plus
DirectPath
Stereo
HeadphoneJack
Left
(SE )
Right
(SE )
Left
(SE )
Right
(SE )
8
Speaker
W
TM
8
Speaker
W
www.ti.com....................................................................................................................................................................................................... SLOS544 – JULY 2008
1.4 W/CH STEREO CLASS-D AUDIO SUBSYSTEM WITH DirectPath HEADPHONE
AMPLIFIER AND 2:1 INPUT MUX
23
Stereo Class-D Amp:
–
1.4 W into 8
from 5.0 V (10% THD + N)
The TPA2050D4 features a stereo Class-D power
amplifier along with a stereo DirectPath headphone
–
1.25 W into 8
from 5.0 V (1% THD + N)
amplifier.
The
TPA2050D4
has
two
stereo
DirectPath Stereo Headphone Amplifier
single-ended (SE) inputs that can be configured as
–
No Output Capacitors Required
one stereo differential input. Both input channels
have a 32-step volume control and the DirectPath
Gain Select for Headphone Amplifier
headphone amplifier has a 4-level gain control for
Eight Programmable Maximum Headphone
coarse volume adjustment. All amplifiers have output
Voltage Limits
short-circuit and thermal- overload protection.
Two Single-Ended or One Differential Stereo
The Class-D amplifiers deliver 1.25 W into 8
at 1%
Input
THD from a 5.0 V supply, and 700 mW from 3.6 V.
2:1 Input MUX with Mode Control
The DirectPath headphone amplifier features an
output voltage limiter to reduce the maximum output
32-Step Volume Control for Both Input
power to one of seven possible limits. The voltage
Channels
limiter is programmed through the I2C interface.
Independent Shutdown for Headphone and
DirectPath eliminates the need for external DC-
Class-D Amplifiers
blocking output capacitors to the headphones. The
Short-Circuit and Thermal-Overload Protection
built-in charge pump creates a negative supply
±8 kV HBM ESD Protection on Headphone
voltage for the headphone amplifier, allowing a 0-V
Outputs
DC bias at the output.
I2C Interface
The DirectPath headphone amplifier gains are 0 dB
25-Ball 2,61 mm × 2,61 mm WCSP
(default), –6 dB, –12 dB, and –20 dB, selected
through the I2C interface. This allows the headphone
volume to be different from the loudspeaker volume if
both are used simultaneously.
Smart Phones / Cellular Phones
Laptop Computers
The TPA2050D4 has a 2:1 input MUX for audio
source selection. The MUX has mode control which
Portable Gaming
directs the input-to-output signal path. Mode and gain
Portable Media Players
controls operate from a 1.8 V compatible I2C
interface.
SIMPLIFIED SYSTEM BLOCK DIAGRAM
The voltage supply range for both the Class-D
amplifiers and the headphone charge pump is 2.5 V
to 5.5 V. The Class-D amplifiers use a combined 7
mA and the headphone amplifier uses 10 mA of
typical
quiescent
current.
Total
supply
current
reduces to less than 2
A.
The TPA2050D4YZK is available in a 25-ball 2.61
mm × 2.61 mm WCSP package.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2
DirectPath is a trademark of Texas Instruments.
3
I2C is a trademark of NXP Semiconductors.
PRODUCTION DATA information is current as of publication date.
Copyright 2008, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.