ETC TPA6100A2

TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
D
D
D
D
D
D
D
D
D
D PACKAGE
(TOP VIEW)
50-mW Stereo Output
Low Supply Current . . . 0.75 mA
Low Shutdown Current . . . 50 nA
Pin Compatible With LM4881 and TPA102†
Pop Reduction Circuitry
Internal Mid-Rail Generation
Thermal and Short-Circuit Protection
Surface-Mount Packaging
– MSOP
– SOIC
1.6-V to 3.6-V Supply Voltage Range
BYPASS
GND
SHUTDOWN
IN2–
1
8
2
7
3
6
4
5
IN1–
VO 1
VDD
VO 2
DGK PACKAGE
(TOP VIEW)
BYPASS
GND
SHUTDOWN
IN2–
† The polarity of the SHUTDOWN pin is reversed.
1
8
2
7
3
6
4
5
description
IN1–
VO 1
VDD
VO 2
The TPA6100A2 is a stereo audio power amplifier packaged in either an 8-pin SOIC package or an 8-pin MSOP
package capable of delivering 50 mW of continuous RMS power per channel into 16-Ω loads. Amplifier gain
is externally configured by a means of three resistors per input channel and does not require external
compensation for settings of 1 to 10.
The TPA6100A2 is optimized for battery applications because of its low supply current, shutdown current, and
THD+N. To obtain the low-supply voltage range, the TPA6100A2 biases BYPASS to VDD/4. A resistor with a
resistance equal to RF must be added from the inputs to ground to allow the output to be biased at VDD/2.
When driving a 16-Ω load with 45-mW output power from 3.3 V, THD+N is 0.04% at 1 kHz, and less than 0.2%
across the audio band of 20 Hz to 20 kHz. For 28 mW into 32-Ω loads, the THD+N is reduced to less than 0.03%
at 1 kHz, and is less than 0.2% across the audio band of 20 Hz to 20 kHz.
typical application circuit
VDD 6
RF
VDD/4
Audio
Input
RI
8
IN 1–
1
BYPASS
4
IN 2–
R
CI
VDD
CS
–
+
VO1 7
–
+
VO2 5
CC
CB
Audio
Input
RI
R
CI
From Shutdown
Control Circuit
3
SHUTDOWN
CC
Bias
Control
2
RF
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.
Copyright  2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
AVAILABLE OPTIONS
PACKAGED DEVICE
TA
SMALL OUTLINE (D)
MSOP (DGK)
MSOP
SYMBOLIZATION
TPA6100A2D
TPA6100A2DGK
AJL
– 40°C to 85°C
Terminal Functions
TERMINAL
NAME
NO.
I/O
DESCRIPTION
BYPASS
1
I
Tap to voltage divider for internal mid-supply bias supply. BYPASS is set at VDD/4. Connect to a
0.1-µF to 1-µF low-ESR capacitor for best performance.
GND
2
I
GND is the ground connection.
IN1–
8
I
IN1– is the inverting input for channel 1.
IN2–
4
I
IN2– is the inverting input for channel 2.
SHUTDOWN
3
I
Active-low input. When held low, the device is placed in a low supply current mode.
VDD
VO1
6
I
7
O
VDD is the supply voltage terminal.
VO1 is the audio output for channel 1.
VO2
5
O
VO2 is the audio output for channel 2.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 V
Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to VDD + 0.3 V
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited
Operating junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 150°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
DISSIPATION RATING TABLE
PACKAGE
TA ≤ 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
D
710 mW
5.68 mW/°C
454 mW
369 mW
DGK
469 mW
3.75 mW/°C
300 mW
244 mW
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
recommended operating conditions
Supply voltage, VDD
Operating free-air temperature, TA
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
MIN
MAX
UNIT
1.6
3.6
V
– 40
85
°C
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
dc electrical characteristics at TA = 25°C, VDD = 3.3 V
PARAMETER
TEST CONDITIONS
PSRR
Power supply rejection ratio
IDD
Supply current
IDD(SD)
Supply current in SHUTDOWN mode
|IIH|
High-level input current (SHUTDOWN)
VDD = 3.3 V, VI= VDD
|IIL|
Low-level input current (SHUTDOWN)
VDD = 3.3 V, VI= 0 V
ZI
Input impedance (IN1–, IN2–)
MIN
VDD = 3.0 V to 3.6 V
TYP
MAX
72
UNIT
dB
0.75
1.2
mA
50
250
nA
1
µA
1
>1
µA
MΩ
ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 16 Ω
PARAMETER
TEST CONDITIONS
PO
THD+N
Output power (each channel)
THD ≤ 0.1%,
f = 1 kHz
Total harmonic distortion + noise
BOM
kSVR
Maximum output power BW
PO = 45 mW,
G = 1,
THD < 0.5%
Supply ripple rejection
SNR
Signal-to-noise ratio
Vn
Noise output voltage (no noise weighting filter)
MIN
TYP
MAX
50
20–20 kHz
UNIT
mW
0.2%
> 20
kHz
f = 1 kHz
52
dB
PO = 50 mW
90
dB
28
µV(rms)
ac operating characteristics, VDD = 3.3 V, TA = 25°C, RL = 32 Ω
PARAMETER
TEST CONDITIONS
PO
THD+N
Output power (each channel)
THD ≤ 0.1%,
f = 1 kHz
Total harmonic distortion + noise
20–20 kHz
BOM
kSVR
Maximum output power BW
PO = 30 mW,
G = 1,
Supply ripple rejection
SNR
Signal-to-noise ratio
Vn
Noise output voltage (no noise weighting filter)
POST OFFICE BOX 655303
THD < 0.2%
MIN
TYP
35
MAX
UNIT
mW
0.2%
> 20
kHz
f = 1 kHz
52
dB
PO = 35 mW
91
dB
28
µV(rms)
• DALLAS, TEXAS 75265
3
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
dc electrical characteristics at TA = 25°C, VDD = 1.6 V
PARAMETER
PSRR
Power supply rejection ratio
IDD
TEST CONDITIONS
MIN
VDD = 1.5 V to 1.7 V
TYP
MAX
UNIT
80
dB
Supply current
1.2
mA
IDD(SD)
Supply current in SHUTDOWN mode
50
|IIH|
High-level input current (SHUTDOWN)
VDD = 1.6 V, VI= VDD
|IIL|
Low-level input current (SHUTDOWN)
VDD = 1.6 V, VI= 0 V
ZI
Input impedance (IN1–, IN2–)
250
nA
1
µA
1
>1
µA
MΩ
ac operating characteristics, VDD = 1.6 V, TA = 25°C, RL = 16 Ω
PARAMETER
TEST CONDITIONS
PO
THD+N
Output power (each channel)
THD ≤ 0.1%,
f = 1 kHz
Total harmonic distortion + noise
BOM
kSVR
Maximum output power BW
PO = 9.5 mW,
G = 0 dB,
THD < 0.4%
Supply ripple rejection
SNR
Signal-to-noise ratio
Vn
Noise output voltage (no noise weighting filter)
MIN
TYP
MAX
9.5
20–20 kHz
UNIT
mW
0.4%
> 20
kHz
f = 1 kHz
53
dB
PO = 9.5 mW
86
dB
18
µV(rms)
ac operating characteristics, VDD = 1.6 V, TA = 25°C, RL = 32 Ω
PARAMETER
TEST CONDITIONS
PO
THD+N
Output power (each channel)
THD ≤ 0.1%,
f = 1 kHz
Total harmonic distortion + noise
20–20 kHz
BOM
kSVR
Maximum output power BW
PO = 6.5 mW,
G = 0 dB,
Supply ripple rejection
SNR
Signal-to-noise ratio
Vn
Noise output voltage (no noise weighting filter)
4
POST OFFICE BOX 655303
THD < 0.3%
MIN
TYP
7.1
MAX
UNIT
mW
0.3%
> 20
kHz
f = 1 kHz
53
dB
PO = 7.1 mW
88
dB
18
µV(rms)
• DALLAS, TEXAS 75265
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
APPLICATION INFORMATION
gain setting resistors, RF, RI, and R
ǒǓ
ǒǓ
The voltage gain for the TPA6100A2 is set by resistors RF and RI according to equation 1.
Gain
+*
RF
RI
or Gain (dB)
+ 20 log
RF
RI
(1)
Given that the TPA6100A2 is a MOS amplifier, the input impedance is very high. Consequently input leakage
currents are not generally a concern, although noise in the circuit increases as the value of RF increases. In
addition, a certain range of RF values is required for proper start-up operation of the amplifier. Taken together
it is recommended that the effective impedance seen by the inverting node of the amplifier be set between
5 kΩ and 20 kΩ. The effective impedance is calculated in equation 2.
Effective Impedance
+ RRF)RRI
F
(2)
I
As an example, consider an input resistance of 20 kΩ and a feedback resistor of 20 kΩ. The gain of the amplifier
would be – 1 and the effective impedance at the inverting terminal would be 10 kΩ, which is within the
recommended range.
For high performance applications, metal film resistors are recommended because they tend to have lower
noise levels than carbon resistors. For values of RF above 50 kΩ, the amplifier tends to become unstable due
to a pole formed from RF and the inherent input capacitance of the MOS input structure. For this reason, a small
compensation capacitor of approximately 5 pF should be placed in parallel with RF. This, in effect, creates a
low-pass filter network with the cutoff frequency defined in equation 3.
fc
+ 2 p R1 C
(3)
F F
For example, if RF is 100 kΩ and CF is 5 pF then fc is 318 kHz, which is well outside the audio range.
For maximum signal swing and output power at low supply voltages like 1.6 V to 3.3 V, BYPASS is biased to
VDD/4. However, to allow the output to be biased at VDD/2, a resistor, R, equal to RF must be placed from the
negative input to ground.
input capacitor, CI
In the typical application, an input capacitor, CI, is required to allow the amplifier to bias the input signal to the
proper dc level for optimum operation. In this case, CI and RI form a high-pass filter with the corner frequency
determined in equation 4.
fc
+ 2 p R1 C
(4)
I I
The value of CI is important to consider, as it directly affects the bass (low frequency) performance of the circuit.
Consider the example where RI is 20 kΩ and the specification calls for a flat bass response down to 20 Hz.
Equation 4 is reconfigured as equation 5.
CI
+ 2 p 1R fc
(5)
I
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
APPLICATION INFORMATION
input capacitor, CI (continued)
In this example, CI is 0.40 µF, so one would likely choose a value in the range of 0.47 µF to 1 µF. A further
consideration for this capacitor is the leakage path from the input source through the input network (RI, CI) and
the feedback resistor (RF) to the load. This leakage current creates a dc offset voltage at the input to the amplifier
that reduces useful headroom, especially in high-gain applications (>10). For this reason a low-leakage
tantalum or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the
capacitor should face the amplifier input in most applications, as the dc level there is held at VDD/4, which is
likely higher than the source dc level. It is important to confirm the capacitor polarity in the application.
power supply decoupling, CS
The TPA6100A2 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling
to ensure that the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also
prevents oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is
achieved by using two capacitors of different types that target different types of noise on the power supply leads.
For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance
(ESR) ceramic capacitor, typically 0.1 µF, placed as close as possible to the device VDD lead, works best. For
filtering lower-frequency noise signals, a larger aluminum electrolytic capacitor of 10 µF or greater placed near
the power amplifier is recommended.
midrail bypass capacitor, CB
The midrail bypass capacitor (CB) serves several important functions. During startup, CB determines the rate
at which the amplifier starts up. This helps to push the start-up pop noise into the subaudible range (so low it
can not be heard). The second function is to reduce noise produced by the power supply caused by coupling
into the output drive signal. This noise is from the midrail generation circuit internal to the amplifier. The capacitor
is fed from a 55-kΩ source inside the amplifier. To keep the start-up pop as low as possible, the relationship
shown in equation 6 should be maintained.
ǒ
CB
1
55 kΩ
1
v
Ǔ ǒC R Ǔ
(6)
I I
As an example, consider a circuit where CB is 1 µF, CI is 1 µF, and RI is 20 kΩ. Inserting these values into the
equation 6 results in: 18.18 ≤ 50 which satisfies the rule. Bypass capacitor (CB) values of 0.47-µF to 1-µF
ceramic or tantalum low-ESR capacitors are recommended for the best THD and noise performance.
output coupling capacitor, CC
In the typical single-supply single-ended (SE) configuration, an output coupling capacitor (CC) is required to
block the dc bias at the output of the amplifier, thus preventing dc currents in the load. As with the input coupling
capacitor, the output coupling capacitor and impedance of the load form a high-pass filter governed by
equation 7.
fc
+ 2 p R1 C
(7)
L C
The main disadvantage, from a performance standpoint, is that the typically small load impedances drive the
low-frequency corner higher. Large values of CC are required to pass low frequencies into the load. Consider
the example where a CC of 68 µF is chosen and loads vary from 32 Ω to 47 kΩ. Table 1 summarizes the
frequency response characteristics of each configuration.
6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
APPLICATION INFORMATION
Table 1. Common Load Impedances vs Low Frequency Output Characteristics in SE Mode
RL
CC
68 µF
Lowest Frequency
32 Ω
10,000 Ω
68 µF
0.23 Hz
47,000 Ω
68 µF
0.05 Hz
73 Hz
As Table 1 indicates, headphone response is adequate and drive into line level inputs (a home stereo for
example) is very good.
The output coupling capacitor required in single-supply SE mode also places additional constraints on the
selection of other components in the amplifier circuit. With the rules described earlier still valid, add the following
relationship:
ǒ
CB
1
55 kΩ
Ǔvǒ ǓƠ
1
CI RI
1
R LC C
(8)
using low-ESR capacitors
Low-ESR capacitors are recommended throughout this application. A real capacitor can be modeled simply as
a resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial effects
of the capacitor in the circuit. The lower the equivalent value of this resistance, the more the real capacitor
behaves like an ideal capacitor.
3.3-V versus 1.6-V operation
The TPA6100A2 was designed for operation over a supply range of 1.6 V to 3.6 V. There are no special
considerations for 1.6-V versus 3.3-V operation as far as supply bypassing, gain setting, or stability. Supply
current is slightly reduced from 0.75 mA (typical) to 0.65 mA (typical). The most important consideration is that
of output power. Each amplifier can produce a maxium output voltage swing within a few hundred millivolts of
the rails with a 10-kΩ load. However, this voltage swing decreases as the load resistance decreases and the
rDS(on) as the output stage transistors becomes more significant. For example, for a 32-Ω load, the maximum
peak output voltage with VDD = 1.6 V is approximately 0.7 V with no clipping distortion. This reduced voltage
swing effectively reduces the maximum undistorted output power.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
MECHANICAL DATA
D (R-PDSO-G**)
PLASTIC SMALL-OUTLINE PACKAGE
14 PIN SHOWN
0.050 (1,27)
0.020 (0,51)
0.014 (0,35)
14
0.010 (0,25) M
8
0.008 (0,20) NOM
0.244 (6,20)
0.228 (5,80)
0.157 (4,00)
0.150 (3,81)
Gage Plane
0.010 (0,25)
1
7
0°– 8°
A
0.044 (1,12)
0.016 (0,40)
Seating Plane
0.069 (1,75) MAX
0.010 (0,25)
0.004 (0,10)
PINS **
0.004 (0,10)
8
14
16
A MAX
0.197
(5,00)
0.344
(8,75)
0.394
(10,00)
A MIN
0.189
(4,80)
0.337
(8,55)
0.386
(9,80)
DIM
4040047 / D 10/96
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion, not to exceed 0.006 (0,15).
8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TPA6100A2
50-mW ULTRALOW VOLTAGE STEREO HEADPHONE
AUDIO POWER AMPLIFIER
SLOS269A – JUNE 2000 – REVISED NOVEMBER 2000
MECHANICAL INFORMATION
DGK (R-PDSO-G8)
PLASTIC SMALL-OUTLINE PACKAGE
0,38
0,25
0,65
8
0,25 M
5
0,15 NOM
3,05
2,95
4,98
4,78
Gage Plane
0,25
1
0°– 6°
4
3,05
2,95
0,69
0,41
Seating Plane
1,07 MAX
0,15
0,05
0,10
4073329/B 04/98
NOTES: A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion.
Falls within JEDEC MO-187
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
9
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its products to the specifications applicable at the time of sale in accordance with
TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary
to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except
those mandated by government requirements.
Customers are responsible for their applications using TI components.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
products or services might be or are used. TI’s publication of information regarding any third party’s products
or services does not constitute TI’s approval, license, warranty or endorsement thereof.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations and notices. Representation
or reproduction of this information with alteration voids all warranties provided for an associated TI product or
service, is an unfair and deceptive business practice, and TI is not responsible nor liable for any such use.
Resale of TI’s products or services with statements different from or beyond the parameters stated by TI for
that product or service voids all express and any implied warranties for the associated TI product or service,
is an unfair and deceptive business practice, and TI is not responsible nor liable for any such use.
Also see: Standard Terms and Conditions of Sale for Semiconductor Products. www.ti.com/sc/docs/stdterms.htm
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright  2001, Texas Instruments Incorporated