TPA2008D2
www.ti.com
SLOS413C – JULY 2003 – REVISED MAY 2004
3-W STEREO CLASS-D AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL
FEATURES
•
•
•
•
•
•
•
DESCRIPTION
3 W Per Channel into 3-Ω Speakers
(THD+N = 10%)
– < 0.045% THD at 1.5 W, 1 kHz, 3-Ω Load
DC Volume Control With 2-dB Steps From
-38 dB to 20 dB
Filter Free Modulation Scheme Operates
Without a Large and Expensive LC Output
Filter
Extremely Efficient Third Generation 5-V
Class-D Technology
– Low Supply Current, 7 mA
– Low Shutdown Control, 1 µA
– Low Noise Floor, -80 dBV
– Maximum Efficiency into 3 Ω, 78%
– Maximum Efficiency into 8 Ω, 88%
– PSRR, -70 dB
Integrated Depop Circuitry
Operating Temperature Range, -40°C to 85°C
Space-Saving, Surface Mount PowerPAD™
Package
APPLICATIONS
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•
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The TPA2008D2 is a third generation 5-V class-D
amplifier from Texas Instruments. Improvements to
previous generation devices include: dc volume control, lower supply current, lower noise floor, higher
efficiency, smaller packaging, and fewer external
components. Most notably, a new filter-free class-D
modulation technique allows the TPA2008D2 to directly drive the speakers, without needing a low-pass
output filter consisting of two inductors and three
capacitors per channel. Eliminating this output filter
saves approximately 30% in system cost and 75% in
PCB area.
The improvements and functionality make this device
ideal for LCD projectors, LCD monitors, powered
speakers, and other applications that demand more
battery life, reduced board space, and functionality
that surpasses currently available class-D devices.
A chip-level shutdown control limits total supply
current to 1 µA, making the device ideal for battery-powered applications. Protection circuitry increases device reliability: thermal and short circuit.
Undervoltage shutdown saves battery power for more
essential devices when battery voltage drops to low
levels.
The TPA2008D2 is available in a 24-pin TSSOP
PowerPAD™package.
LCD Projectors
LCD Monitors
Powered Speakers
Battery Operated and Space Constrained
Systems
EFFICIENCY
vs
OUTPUT POWER
100
8 Ω Speaker
90
4 Ω Speaker
Efficiency − %
80
3 Ω Speaker
70
60
50
40
30
VDD = 5 V
No Filter
20
10
0
0
0.5
1
1.5
2
2.5
PO − Output Power − W
3
3.5
THD+N − Total Harmonic Distortion + Noise − %
TOTAL HARMONIC DISTORTION + NOISE
vs
OUTPUT POWER
20
10
VDD = 5 V
RL = 3 Ω
Gain = 0 dB
f = 1 kHz
1
f = 20 kHz
0.1
f = 20 Hz
0.01
0.01
0.1
1
4
PO − Output Power − W
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.
PowerPAD is a trademark of Texas Instruments.
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 © 2003–2004, Texas Instruments Incorporated
TPA2008D2
www.ti.com
SLOS413C – JULY 2003 – REVISED MAY 2004
These devices have limited built-in ESD protection. The leads should be shorted together or the device
placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
AVAILABLE OPTIONS
TSSOP PowerPAD (PWP) (1)
(1)
Device
TPA2008D2PWP (1)
Package Designator
PWP (1)
The PWP package is available taped and reeled. To order a taped
and reeled part, add the suffix R to the part number (e.g.,
TPA2008D2PWPR).
PWP PACKAGE
(TOP VIEW)
LINN
LINP
SHUTDOWN
PVDDL
LOUTP
PGNDL
PGNDL
LOUTN
PVDDL
COSC
ROSC
AGND
2
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
RINN
RINP
BYPASS
PVDDR
ROUTP
PGNDR
PGNDR
ROUTN
PVDDR
NC
VOLUME
VDD
TPA2008D2
www.ti.com
SLOS413C – JULY 2003 – REVISED MAY 2004
TERMINAL FUNCTIONS
TERMINAL
NO.
NAME
I/O
DESCRIPTION
AGND
12
-
Analog ground
BYPASS
22
I
Tap to voltage divider for internal mid-supply bias generator used for internal analog reference.
COSC
10
I
A capacitor connected to this terminal sets the oscillation frequency in conjunction with ROSC. For
proper operation, connect a 220-pF capacitor from COSC to ground.
LINN
1
I
Negative differential audio input for left channel
LINP
2
I
Positive differential audio input for left channel
LOUTN
8
O
Negative audio output for left channel
LOUTP
5
O
Positive audio output for left channel
NC
15
I
No connection
PGNDL
6, 7
-
Power ground for left channel H-bridge
PGNDR
18, 19
-
Power ground for right channel H-bridge
PVDDL
4, 9
PVDDR
16, 21
Power supply for left channel H-bridge
Power supply for right channel H-bridge
RINN
24
I
Positive differential audio input for right channel
RINP
23
I
Negative differential audio input for right channel
ROSC
11
I
A resistor connected to the ROSC terminal sets the oscillation frequency in conjunction with COSC. For
proper operation, connect a 120-kΩ resistor from ROSC to ground.
ROUTN
17
O
Negative output for right channel
ROUTP
20
O
Positive output for right channel
SHUTDOWN
3
I
Places the amplifer in shutdown mode if a TTL logic low is placed on this terminal; normal operation if a
TTL logic high is placed on this terminal.
VDD
13
-
Analog power supply
VOLUME
14
I
DC volume control for setting the gain on the internal amplifiers. The dc voltage range is 0 to VDD.
-
-
Connect to analog ground and the power grounds must be soldered down in all applications to properly
secure device on the PCB.
Thermal Pad
3
TPA2008D2
www.ti.com
SLOS413C – JULY 2003 – REVISED MAY 2004
FUNCTIONAL BLOCK DIAGRAM
VDD
AGND
PVDD
VDD
Gain
Adj.
RINN
Gate
Drive
ROUTN
PGND
PVDD
Gate
Drive
Gain
Adj.
RINP
ROUTP
PGND
SHUTDOWN
Volume
Control
VOLUME
Biases
and
References
Startup
Protection
Logic
Ramp
Generator
COSC
Short
Circuit
Protection
Short
Circuit
Protection
VDD
ROSC
Thermal
BYPASS
PVDD
LINP
Gain
Adj.
Gate
Drive
LOUTP
PGND
PVDD
LINN
Gain
Adj.
Gate
Drive
LOUTN
PGND
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted
(1)
UNIT
VDD,PVDD
Supply voltage range
VI (RINN, RINP, LINN,
LINP, VOLUME)
Input voltage range
Continuous total power dissipation
-0.3 V to 6 V
0 V to VDD
See Dissipation Rating Table
TA
Operating free-air temperature range
-40°C to 85°C
TJ
Operating junction temperature range
-40°C to 150°C
Tstg
Storage temperature range
-65°C to 85°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
(1)
4
260°C
Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating
conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
TPA2008D2
www.ti.com
SLOS413C – JULY 2003 – REVISED MAY 2004
DISSIPATION RATINGS TABLE
PACKAGE
TA≤ 25°C
DERATING FACTOR
TA = 70°C
TA = 85°C
PWP
2.18 W
21.8 mW/°C
1.2 W
872 mW
RECOMMENDED OPERATING CONDITIONS
MIN
VDD
Supply voltage
Volume terminal voltage
VIH
High-level input voltage
SHUTDOWN
VIL
Low-level input voltage
SHUTDOWN
MAX
UNIT
4.5
5.5
V
0
VDD
V
2
V
0.8
V
PWM frequency
200
300
kHz
TA
Operating free-air temperature
-40
85
°C
TJ
Operating junction temperature
125
°C
ELECTRICAL CHARACTERISTICS
TA= 25°C, VDD = PVDD = 5 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
| VOS |
Output offset voltage (measured differentially)
VI = 0 V, AV = 20 dB, RL = 8Ω
PSRR
Power supply rejection ratio
VDD = PVDD = 4.5 V to 5.5 V
| IIH |
High-level input current
VDD = PVDD = 5.5 V, VI= VDD = PVDD
| IIL |
Low-level input current
VDD = PVDD = 5.5 V, VI = 0 V
IDD
Supply current
No filter (no load)
IDD(max)
RMS supply current at max power
RL = 3 Ω, PO = 2.5 W/channel (stereo)
IDD(SD)
Supply current in shutdown mode
SHUTDOWN = 0 V
Drain-source on-state resistance
VDD = 5 V, IO = 500 mA,
TJ= 25°C
rds(on)
MIN
TYP MAX
5
25
mV
1
µA
-70
7
UNIT
dB
1
µA
15
mA
1.8
A
50 1000
High side
450
600
Low side
450
600
TYP
MAX
nA
mΩ
OPERATING CHARACTERISTICS
TA= 25°C, VDD = PVDD = 5 V, RL = 3 Ω, Gain = 0 dB (unless otherwise noted)
PARAMETER
TEST CONDITIONS
f = 1 kHz, RL = 3 Ω, Stereo
operation
THD+N = 1%
MIN
2.5
UNITS
PO
Output power
THD+N
Total harmonic distortion plus noise
BOM
Maximum output power bandwidth
THD = 5%
20
kHz
SNR
Signal-to-noise ratio
Maximum output at THD+N