ETC TMPA2156D2

Tai-1 Microelectronics
TMPA2156D2
Preliminary
www.taimec.com.tw
Rev.1.0
September 7, 2005
0.73W/CH STEREO CLASS-D AUDIO POWER AMPLIFIER
GENERAL DESCRIPTION
FEATURES
The TMPA2156D2 is a STEREO class-D audio power amplifier
♦ 2.5V to 6V Single Supply
IC. With SE(Single-Ended) configuration, it delivers up to
♦ Up to 0.73W/CH at 5V, 3 ohms
0.73W/CH power into a 3 ohms load or 0.6W/CH power into a 4
ohm load or 0.33W/CH power into an 8 ohm load. No external
heat-sink is required.
♦ Up to 85% Power Efficiency
♦ Automatic output power control (APC)
♦ 2.2mA Quiescent Current at 5V
For multiple-input applications, independent gain control and
♦ Less Than 0.2uA Shutdown Current
corner frequency can be implemented by summing the input
♦ Popless Power-Up, Shutdown and Recovery
sources through resistor ratio and input capacitor values.
Automatic voltage gain control makes the best use of battery.
♦ Single-Ended output
♦ Thermal Shutoff and Automatic Recovery
♦ Short-Circuit Protection
Analog input signal is converted into digital output which drives
♦
directly to the speaker. High power efficiency is achieved due to
Package
digital output at the load. The audio information is embedded in
PWM(Pulse Width Modulation).
APPLICATIONS
TSSOP8, SOP8 Available
For best performance, please refer to
//www.taimec.com.tw/data/Tmpa2155EVM/tmpa2156d2EVM.pdf
Multimedia application includes Cellular Phones, PDAs, 2.1
for PCB layout.
channel, USB audio. It is also ideal for other portable devices
like Wireless Radios.
REFERENCE CIRCUIT
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TMPA2156D2
Preliminary
Tai-1 Microelectronics
www.taimec.com.tw
Rev.1.0
September 7, 2005
TOP VIEW
(Please email [email protected] for complete datasheet.)
Tai-1 Microelectronics reserves the right to make corrections, modifications, enhancements, improvements, and other changes
to its products and services at any time and to discontinue any product or service without notice. Customers are responsible
for their products and applications using Tai-1 Microelectronics components.
Note that the external components or PCB layout should be designed not to generate abnormal
voltages to the chip to prevent from latch up which may cause damage to the device.
Typical Application
C3
1uF
C7
10uF
VDD
VDD
R7
3k
+
C4
1uF
C5
1uF
L1
R2
100
VI1
C1
C2
VI2
0.47uF
0.47uF
22k
22k
R4
R5
1
2
3
4
VO1
GND
IN1
IN2
Vo2 8
VDD7
VDDA
6
SDNB5
VDDA R3
R1
100
+
33uH
100
SDNB
C8
VO1
1000uF
L2
R6
100K
C9
VO2
1000uF
C6
1uF
R8
3k
R9
3k
S1
switch
2156D2
PHONEJACK STEREO
+
33uH
JP1
J1
R13
3k
C10 +
100uF
VDD
ABSOLUTE MAXIMUM RATINGS
Over operating free-air temperature range unless otherwise noted(1)
Supply voltage, VDD
In normal mode
-0.3V to 6V
V
-0.3V to 7V
V
-0.3V to VDD+0.3V
V
In shutdown mode
Input voltage, V I
Continuous total power dissipation
Operating free-air temperature, TA
See package dissipation ratings
。C
-20 to 85
Operating junction temperature, TJ
-20 to 150
Storage temperature, Tstg
-40 to 150
。C
。C
(1) 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.
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TMPA2156D2
Preliminary
Tai-1 Microelectronics
www.taimec.com.tw
Rev.1.0
September 7, 2005
RECOMMENDED OPERATING CONDITONS
MIN
Supply voltage, VDD
NOM
MAX
UNIT
2.5
6
V
V
High-level input voltage, V IH
SDNB
2
VDD
Low-level input voltage, VIL
SDNB
0
0.8
V
85
。C
Operating free-air temperature, TA
-20
PACKAGE DISSIPATION RATINGS
PACKGE
SOP8
DERATING
TA ≤ 25。C
TA = 70。C
TA = 85。C
FACTOR
POWER RATING
POWER RATING
POWER RATING
6.39mW/。C
0.799W
0.511W
0.415W
ELECTRICAL CHARACTERISTICS
TA=25。C (unless otherwise noted)
PARAMETER
PSRR
Power supply rejection ratio
TEST CONDITIONS
MIN
VDD=VDDA=2.5V to 5.5V
VDD=VDDA=2.5V to 5.5V,
CMRR
Common mode rejection ratio
│IIH│
High-level input current
VDD=VDDA=5.5V, VI=5.8V (SDNB)
│IIL│
Low-level input current
VDD=VDDA=5.5V, VI=-0.3V (SDNB)
IQ
Quiescent current
VDD=VDDA=5V, no load
IQ (SD)
Shutdown current
rDS(on)
Static output resistance
VDD=VDDA=5.5V
f(sw)
Switching frequency
VDD=VDDA=2.5V to 5.5V
*Av
Voltage gain
VDD=VDDA=2.5V to 5.5V, RL=8Ω
RSDN
Resistance from shutdown to GND
V(SDNB)=5V
ZI
Input impedance
VIC=1Vpp, RL=8Ω
TYP
MAX
UNIT
-75
-55
dB
-55
-50
dB
μA
30
V(SDNB)=0.8V,
VDD=VDDA=2.5V to 5.5V
1
μA
2.2
3
mA
0.2
0.5
μA
600
mΩ
200
250
300
kHz
17
21
25
V/V
200
12
15
kΩ
18
kΩ
*The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V
Gain = 320kohms
Ri + 15kohms
where Ri is the external serial resistance at the input pin.
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Preliminary
Tai-1 Microelectronics
www.taimec.com.tw
TMPA2156D2
Rev.1.0
September 7, 2005
OPERATING CHARACTERISTICS
TA=25。C, RL=8Ω speaker (unless otherwise noted)
PARAMETER
TEST CONDITIONS
RL=8Ω
PO
Output power/CH
THD+N
RL=4Ω
Total harmonic distortion plus noise
MIN TYP MAX
UNIT
0.33
VDD=VDDA=5V.
THD+N=10%,f=1kHz.
0.6
RL=3Ω
0.73
VDD=VDDA=5V, PO=0.2W, RL=8Ω, f=1kHz
0.55
VDD=VDDA=5V, PO=0.3W, RL=4Ω, f=1kHz
0.55
VDD=VDDA=5V, PO=0.4W, RL=3Ω, f=1kHz
0.64
W
%
SNR
Signal-to-noise ratio
VDD=VDDA=5V, PO=1W, RL=8Ω
85
dB
Crosstalk
Crosstalk between outputs
VDD=AVDD=5V, PO=1W RL=8Ω
-60
dB
TERMINAL FUNCTIONS
TERMINAL
I/O
NAME
DESCRIPTION
PIN NO
GND
2
I
Digital ground
IN2
4
I
Channel 2 input
IN1
3
I
Channel 1 input
SDNB
5
I
Shutdown (active low logic)
VDD
7
I
Digital Power supply
VDDA
6
I
Analog Power supply
VO1
1
O
Channel 1 output
VO2
8
O
Channel 2 output
TYPICAL CHARACTERISTICS
Note 1. Input coupling 1µF capacitors are used for all measurements.
2. LC filter is used for THD+N measurement and power efficiency measurement.
3. Characteristic frequency of the LC filter is set 41KHz unless otherwise specified.
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Tai-1 Microelectronics
TMPA2156D2
Preliminary
www.taimec.com.tw
Rev.1.0
September 7, 2005
APPLICATION INFORMATION
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Tai-1 Microelectronics
Preliminary
www.taimec.com.tw
TMPA2156D2
Rev.1.0
September 7, 2005
l Input Resistors and Gain
The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V
Gain = 320kohms where Ri is the external serial resistance at the input pin.
Ri + 15kohms
Note:Please refer to document 010 APP for more application examples.
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Preliminary
Tai-1 Microelectronics
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TMPA2156D2
Rev.1.0
September 7, 2005
DETAILED DESCRIPTION
Efficiency
The output transistors of a class D amplifier act as switches. The power loss is mainly due to
the turn on resistance of the output transistors when driving current to the load. As the turn on
resistance is so small that the power loss is small and the power efficiency is high. With 8 ohm
load the power efficiency can be better than 85%.
Shutdown
The shutdown mode reduces power consumption. A LOW at shutdown pin forces the device in
shutdown mode and a HIGH forces the device in normal operating mode. Shutdown mode is
useful for power saving when not in use. This function is useful when other devices like
earphone amplifier on the same PCB are used but class D amplifier is not necessary.
Internal circuit for shutdown is shown below.
Pop-less
The setup time for the internal circuitry to be stable to drive the speaker is quite fast
(<100ms). But for Single-ended outputs the set up time for the output circuit to charge up the
output coupling capacitor (=1000uF) to half power voltage is quite long. As shown in the
following diagram, the RC constant caused by the voltage divider of equivalent resistance of
1.5k ohms(3kohms//3kohms) and the capacitance of 1000uF of the output coupling capacitor is
1.5 seconds. So to save pop noise the shutdown pin(SDNB) has to be LOW during power up. In
addition the shutdown pin has to stay LOW for about 5 seconds to wait for the output coupling
capacitor to be charged to half supply voltage.
Class-D amplifier
+
1000uF
+
3k
3k
PVCC
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Tai-1 Microelectronics
TMPA2156D2
Preliminary
www.taimec.com.tw
Rev.1.0
September 7, 2005
Voltage gain
The voltage gain is defined in the table on page 3. For lower voltage gain one can add external
input resistors to input pins.
Automatic output Power Control (APC)
The voltage gain is self adjusted in the chip over voltage range. This means that, regardless
supply voltage change, the output power keeps about the same for a given input level from
VDD=5.5v to 2.5v. It allows the best use of the battery.
Output filter
Ferrite bead filter can be used for EMI purpose. The ferrite filter reduces EMI around 1 MHz and
higher(FCC and CE only test radiated emissions greater than 30 MHz). When selecting a
ferrite bead, choose one with high impedance at high frequencies, but low impedance at low
frequencies.
Use an LC output filter if there are low frequency(<1 MHz)EMI sensitive circuits and/or there
are long wires from the amplifier to the speaker. EMI is also affected by PCB layout and the
placement of the surrounding components.
The suggested LC values for different speaker impendence are showed in following figures for
reference.
Typical LC Output Filter, Speaker Impedance=4Ω
Typical LC Output Filter, Speaker Impedance=6Ω & 8Ω
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Tai-1 Microelectronics
Preliminary
www.taimec.com.tw
TMPA2156D2
Rev.1.0
September 7, 2005
Typical Ferrite Chip Bead Filter
(Chip bead example:遠越科技 KML2012Q102N
1kohms@100MHz, DCR=0.2ohms, I=1A)
EARPHONE USE
Class-D output can be used to drive earphone. However to avoid high power to overdrive
earphone and to prevent human ear to accidentally be hurt, a resistor has to be put in series
with the earphone speaker. Typically a resistor of 330 ohms is adequate for this purpose.
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Tai-1 Microelectronics
Preliminary
www.taimec.com.tw
TMPA2156D2
Rev.1.0
September 7, 2005
Over temperature protection
A temperature sensor is built in the device to detect the temperature inside the device. When
a high temperature around 145oC and above is detected the switching output signals are
disabled to protect the device from over temperature. Automatic recovery circuit enables the
device to come back to normal operation when the internal temperature of the device is below
around 120oC.
Over temperature protection
A temperature sensor is built in the device to detect the temperature inside the device. When
a high temperature around 145oC and above is detected the switching output signals are
disabled to protect the device from over temperature. Automatic recovery circuit enables the
device to come back to normal operation when the internal temperature of the device is below
around 120oC.
Over current protection
A current detection circuit is built in the device to detect the switching current of the output
stages of the device. It disables the device when the current is beyond about 3.5amps. It
protects the device when there is an accident short between outputs or between output and
power/gnd pins. It also protects the device when an abnormal low impedance is tied to the
output. High current beyond the specification may potentially causes electron migration and
permanently damage the device. Shutdown or power down is necessary to resolve the
protection situation. There is no automatic recovery from over current protection.
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Preliminary
Tai-1 Microelectronics
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TMPA2156D2
Rev.1.0
Physical Dimensions
September 7, 2005
( IN MILLIMETERS)
E
1
H
5
8
4
0.05TYP.
0.016TYP.
0.063
0.120
SYMBOLS
MIN.
MAX.
A
0.053
0.069
A1
0.004
0.010
D
0.189
0.196
E
0.150
0.157
H
0.228
0.244
SOP8
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TMPA2156D2
Preliminary
Tai-1 Microelectronics
www.taimec.com.tw
Rev.1.0
Physical Dimensions
( IN MILLIMETERS)
SYMBOLS
MIN.
NDM.
MAX.
A
-
-
1.20
A1
0.05
-
0.15
A2
0.96
1.01
1.06
D
2.90
3.00
3.10
E
E1
September 7, 2005
6.40 BSC
4.30
4.40
4.50
TSSOP8
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Tai-1 Microelectronics
Preliminary
www.taimec.com.tw
TMPA2156D2
Rev.1.0
September 7, 2005
IMPORTANT NOTICE
Tai-1 Microelectronics Corp. reserves the right to make changes to its products and services and to
discontinue any product or service without notice. Customers should obtain the latest relevant information for
reference. Testing and quality control techniques are used to screen the parameters. Testing of all parameters
of each product is not necessarily performed.
Tai-1 Microelectronics Corp. assumes no liability for applications assistance or customer product design. To
minimize the risks associated with customer products and applications, customers should provide adequate
design and operating safeguards.
Reproduction of information in data sheets or related documentation is permissible only if reproduction is
without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Tai-1
Microelectronics Corp. is not responsible or liable for such altered documentation.
Resale of Tai-1 Microelectronics Corp. products or services with statements different from the parameters
stated by Tai-1 Microelectronics Corp. for that product or service voids all express and any implied warranties.
Tai-1 Microelectronics Corp. is not responsible or liable for any such statements.
Copyright ©2005,Tai-1 Microelectronics Corp.
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