STMICROELECTRONICS TDA7266P

TDA7266P
3+3W DUAL BRIDGE AMPLIFIER
PRODUCT PREVIEW
1
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FEATURES
TECHNOLOGY BI20II
WIDE SUPPLY VOLTAGE RANGE (3.5 - 12V)
OUTPUT POWER:
– 3+3W @THD = 10%, RL = 8Ω, VCC = 7.5V
– 4+4W Music Power @THD = 10%, RL = 8Ω,
VCC = 8.5V
SINGLE SUPPLY
MINIMUM EXTERNAL COMPONENTS:
– NO SVR CAPACITOR
– NO BOOTSTRAP
– NO BOUCHEROT CELLS
– INTERNALLY FIXED GAIN
STAND-BY & MUTE FUNCTIONS
SHORT CIRCUIT PROTECTION
THERMAL OVERLOAD PROTECTION
Figure 1. Package
PowerSSO24 (Slug Down)
Table 1. Order Codes
Part Number
Package
TDA7266P
PowerSSO24 (Slug Down)
2
DESCRIPTION
The TDA7266P is a dual bridge amplifier specially
designed for LCD TV/Monitor, PC Motherboard, TV
and Portable Audio applications.
Figure 2. Test and Application Diagram
VCC
C3 0.22µF
+5V
S-GND
ST-BY
7
8
+
5
OUT1+
6
OUT1-
20
OUT2+
19
OUT2-
C2
100nF
C7
100nF
14
R3 10K
11
C4
10µF
Vref
C5 0.22µF
IN2
MUTE
C1
470µF
18
17
R4 10K
10
+
+
-
C6
1µF
1
PW-GND
24
+
D03AU1531A
July 2004
This is preliminary information on a new product foreseen to be developed. Details are subject to change without notice.
REV. 2
1/12
TDA7266P
Table 2. Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
Vs
Supply Voltage
20
V
IO
Output Peak Current (internally limited)
1.5
A
Top
Operating Temperature
0 to 70
°C
-40 to 150
°C
Tstg, Tj
Storage and Junction Temperature
Figure 3. Pin Connection (Top view)
PW GND
1
24
PW GND
N.C.
2
23
N.C.
N.C.
3
22
N.C.
N.C.
4
21
N.C.
OUT1+
5
20
OUT2+
OUT1-
6
19
OUT2-
+VS
7
18
+VS
IN1
8
17
IN2
N.C.
9
16
N.C.
MUTE
10
15
N.C.
STBY
11
14
SGND
N.C.
12
13
N.C.
D03AU1532
Table 3. Themal Data
Symbol
R th j-case
2/12
Parameters
Thermal Resistance Junction to Case
Typ.
Value
Unit
1.5
°C/W
TDA7266P
Table 4. Electrical Characteristcs
(Refer to test circuit; VCC = 7.5V, RL = 8Ω, f = 1KHz, Tamb = 25°C unless otherwise specified)
Symbol
VCC
Iq
Parameter
Supply Range
Min.
Output Offset Voltage
PO
Output Power
PO
Output Music Power (*)
Total Harmonic Distortion
Typ.
3.5
Total Quiescent Current
VOS
THD
Test Condition
CT
AMUTE
Supply Voltage Rejection
120
THD 10%
PO = 1W
f = 100Hz, VR =0.5V
mV
3
W
4
W
0.03
0.2
%
1
%
Crosstalk
46
60
dB
Mute Attenuation
60
80
dB
150
°C
Closed Loop Voltage Gain
25
26
Voltage Gain Matching
Ri
Input Resistance
VTMUTE
Mute Threshold
eN
mA
dB
GV
IST-BY
V
56
Thermal Threshold
VTST-BY
12
40
Tw
∆GV
Unit
40
PO = 0.1W to 2W
f = 100Hz to 15KHz
SVR
Max.
dB
0.5
dB
25
30
for VCC > 6.4V; Vo = -30dB
2.3
2.9
4.1
V
for VCC < 6.4V; Vo = -30dB
VCC/2
-1
VCC/2
-0.75
VCC/2
-0.5
V
0.8
1.3
1.8
V
100
µA
St-by Threshold
St-by Current V6 = GND
Total Output Voltage
27
A Curve
150
KΩ
µV
(*) Measured on demoboard of figure 8 with gaussian noise signal which simulates Music/Speech programmes.
3/12
TDA7266P
3
APPLICATIVE SUGGESTIONS
3.1 STAND-BY AND MUTE FUNCTIONS
3.1.1 (A) Microprocessor Application
In order to avoid annoying "Pop-Noise" during Turn-On/Off transients, it is necessary to guarantee the right Stby and mute signals sequence.It is quite simple to obtain this function using a microprocessor (Fig. 4 and 5).
At first St-by signal (from µP) goes high and the voltage across the St-by terminal (Pin 11) starts to increase
exponentially. The external RC network is intended to turn-on slowly the biasing circuits of the amplifier, this to
avoid "POP" and "CLICK" on the outputs.
When this voltage reaches the St-by threshold level, the amplifier is switched-on and the external capacitors in
series to the input terminals (C1, C3) start to charge.
It's necessary to mantain the mute signal low until the capacitors are fully charged, this to avoid that the device
goes in play mode causing a loud "Pop Noise" on the speakers.
A delay of 100-200ms between St-by and mute signals is suitable for a proper operation.
Figure 4. Microprocessor Application
VCC
C1 0.22µF
IN1
7
8
+
5
C5
470µF
OUT1+
6
OUT1-
20
OUT2+
19
OUT2-
18
-
ST-BY R1 10K
11
C2
10µF
S-GND
µP
14
Vref
C3 0.22µF
IN2
MUTE R2 10K
17
+
+
-
10
C4
1µF
PW-GND
1
-
24
+
D03AU1533
4/12
C6
100nF
TDA7266P
Figure 5. Microprocessor Driving Signals
+VS(V)
+7.5
VIN
(mV)
VST-BY
pin 11
1.8
1.3
0.8
VMUTE
pin 10
4.1
2.9
2.3
Iq
(mA)
VOUT
(V)
OFF
ST-BY
PLAY
MUTE
MUTE
ST-BY
OFF
D03AU1535A
3.1.2 B) Low Cost Application
In low cost applications where the µP is not present, the suggested circuit is shown in fig.6.
The St-by and mute terminals are tied together and they are connected to the supply line via an external voltage
divider.
The device is switched-on/off from the supply line and the external capacitor C4 is intended to delay the St-by
and mute threshold exceeding, avoiding "Popping" problems.
So to avoid any popping or clicking sond, it is important to clock:
a Correct Sequence: At turn-ON, the Stand-by must be removed at first, then the Mute must be released after a delay of about 100-200ms. On the contrary at turn-OFF the Mute must be activated
as first and then the Stand-by.
With the values suggested in the Application circuit the right operation is guaranteed.
b Correct Threshold Voltages: In order to avoid that due to the spread in the internal thresholds (see
the above limits) a wrong external voltage causes uncertain commutations for the two functions we
suggest to use the following values:
Mute for Vcc>6.4V
: VT = 2.3V
Mute for Vcc<6.4V
: VT = Vcc/2 - 1
Stand-by
: VT = 0.8V
5/12
TDA7266P
Figure 6. Stand-alone low-cost Application
VCC
C3 0.22µF
R1
24K
5
C1
470µF
OUT1+
6
OUT1-
20
OUT2+
19
OUT2-
18
+
IN1
ST-BY
R2
47K
7
8
C2
100nF
C7
100nF
11
C4
10µF
S-GND
14
-
Vref
C5 0.22µF
+
17
+
IN2
-
MUTE
PW-GND
10
1
-
24
+
D03AU1534A
Figure 7. Application Circuit
VCC
R1
+5V
JP1
C3 0.22µF
R2
IN1
S-GND
ST-BY
7
8
+
5
OUT1+
6
OUT1-
20
OUT2+
19
OUT2-
14
R3 10K
11
C4
10µF
Vref
C5 0.22µF
IN2
MUTE
C1
470µF
18
17
R4 10K
10
+
+
-
C6
1µF
1
PW-GND
24
+
D03AU1551
6/12
C2
100nF
C7
100nF
TDA7266P
Figure 8. PCB Component Layout
Figure 9. PCB Copper Top (Top view)
Figure 10. PCB Copper Bottom (Top view)
7/12
TDA7266P
4
PCB LAYOUT AND EXTERNAL COMPONENTS
Regarding the PCB layout care must be taken for three main subjects:
1) Signal and Power Gnd separation
2) Dissipating Copper Area
3) Filter Capacitors positioning
1) Signal and Power Gnd separation:
To the Signal GND must be referred the Audio Input Signals, the Mute and Stand-by Voltages and the
device PIN.14. This Gnd path must be as clean as possible in order to improve the device THD+Noise
and to avoid spurious oscillations across the speakers.
The Power GND is directly connected to the Output power Stage transistors (Emitters) and is crossed
by large amount of current, this path is also used in this device to dissipate the heating generated (no
needs of external heatsinker).
Referring to the typical application circuit, the separation between the two GND paths must be obtained
connecting them separately (star routing) to the bulk
Electrolithic capacitor C1 (470µF).
Regarding the Power Gnd dimensioning we have to consider the Dissipated Power the Thermal Protection Threshold and the Package thermal Characteristics.
2) Dissipating Copper Area:
Dissipated Power:
The max dissipated power happens for a THD near 1% and is given by the formula:
2
V CC
P dmax ( W ) = 2 ⋅ -------------- + Iq V CC
2 Rl
π -----2
This gives for: Vcc = 7.5V, Rl = 8Ω ,Iq = 40mA a dissipated power of Pd = 3W.
Thermal Protection:
The thermal protection threshold is placed at a junction temperature of 150°C.
Package Thermal Characteristics:
The thermal resistance Junction to Ambient obtainable with a GND copper Area of 3x3 cm and with 16 via
holes (see picture) is about 25°C/W. This means that with the above mentioned max dissipated Power
(Pd=3W) we can expect a 75°C, this gives a safety margin before the thermal protection intervention in the
consumer environments where a 50°C ambient is specified as maximum
Figure 11.
3)Filter Capacitors Positioning:
The two Ceramic capacitors C2/C7 (100nF) must be placed as close as possible
respectively to the two Vcc pins ( 7 - 18) in order to avoid the possibiltiy of oscillations arising on the
output Audio signals.
8/12
TDA7266P
5
TYPICAL CHARACTERISTICS (Referred to application circuit of figure 8 unless otherwise specified)
Figure 15. Gain vs Frequency
Figure 12. Distortion vs Frequency
Level(dBr)
THD(%)
5.0000
10
4.0000
Vcc = 7.5V
Rl = 8 ohm
Pout = 1W
3.0000
Vcc = 7.5V
Rl = 8 ohm
1
2.0000
1.0000
0.0
-1.000
Pout = 100mW
0.1
-2.000
-3.000
Pout = 2W
-4.000
-5.000
0.010
100
1k
10
20k
10k
100
1k
10k
100k
frequency (Hz)
frequency (Hz)
Figure 16. Mute Attenuation vs Vpin.10
Figure 13. Distortion vs Output Power
% 10
5
2
Attenuation (dB)
10
Vs= 7.5V
Rl= 8 Ohm
F= 1 KHz
0
-10
-20
1
-30
0.5
-40
-50
0.2
-60
0.1
-70
0.05
-80
-90
0.02
-100
0.01
100m
200m
300m 400m500m
W
700m
1
2
3
1
2.5
3
3.5
4
4.5
5
Vpin.10(V)
Attenuation (dB)
% 10
5
Vs= 8 .5V
Rl= 8 Ohm
F= 1 KHz
1
0.5
0.2
0.1
0.05
0.02
0.01
100m
2
Figure 17. Stand-By attenuation vs Vpin 11
Figure 14. Distortion vs Output Power
2
1.5
200m
300m 400m
600m 800m
W
1
2
3
4
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
2
2.2 2.4
Vpin.11 (V)
9/12
TDA7266P
Figure 18. PowerSSO24 Mechanical Data & Package Dimensions
DIM.
mm
MIN.
TYP.
inch
MAX.
MIN.
2.47
0.084
TYP.
MAX.
A
2.15
A2
2.15
2.40
0.084
0.094
a1
0
0.075
0
0.003
b
0.33
0.51
0.013
0.020
c
D
(1)
E (1)
0.23
0.32
0.009
0.012
10.10
10.50
0.398
0.413
7.4
7.6
0.291
0.299
e
0.8
e3
8.8
G
h
L
0.346
0.004
0.06
10.10
10.50
0.002
0.398
0.40
0.55
N
OUTLINE AND
MECHANICAL DATA
0.031
0.10
G1
H
0.097
0.85
0.413
0.016
0.022
0.033
10˚ (max)
X
4.10
4.70
0.161
0.185
Y
6.50
7.10
0.256
0.279
(1) “D and E1” do not include mold flash or protusions.
Mold flash or protusions shall not exceed 0.15mm (0.006”)
(2) No intrusion allowed inwards the leads.
(3) Flash or bleeds on exposed die pad shall not exceed 0.4 mm
per side
PowerSSO24
7412828 A
10/12
TDA7266P
Table 5. Revision History
Date
Revision
Description of Changes
May 2004
1
First Issue
July 2004
2
Electrical Characteristics: Deleted TYP. Value VCC
11/12
TDA7266P
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics.
All other names are the property of their respective owners
© 2004 STMicroelectronics - All rights reserved
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