TPA2050D4 Datasheet, PDF (1/29 Pages) Texas Instruments – 1.4 W/CH STEREO CLASS-D AUDIO SUBSYSTEM WITH DirectPath™ HEADPHONE AMPLIFIER AND 2:1 INPUT MUX

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