STMICROELECTRONICS TS4909IQT

TS4909
Dual mode low power 150mW stereo headphone amplifier
with capacitor-less and single-ended outputs
Features
DFN10 (3x3)
■
No output coupling capacitors necessary
Pop-and-click noise reduction circuitry
■ Operating from VCC = 2.2V to 5.5V
■
■
■
Standby mode active low
Output power:
– 158mW @5V, into 16Ω with 1% THD+N
max (1kHz)
– 52mW @3.0V into 16Ω with 1% THD+N
max (1kHz)
Ultra low current consumption: 2.0mA typ.@3V
Ultra low standby consumption: 10nA typ.
High signal-to-noise ratio: 105 dB typ.@5V
High crosstalk immunity: 110dB (F=1kHz) for
single-ended outputs
PSRR: 72dB (F=1kHz), inputs grounded, for
phantom ground outputs
Low tWU: 50ms in PHG mode, 100ms in SE mode
■
Available in lead-free DFN10 3x3mm
■
■
■
■
■
■
Pin connections (top view)
Vin1
1
10
Stdby
2
9
Vout1
SE/PHG
3
8
Vout3
Bypass
4
7
Vout2
Vin2
5
6
Gnd
Vdd
Functional block diagram
Vdd
Vin1
SE/PHG
Vout1
Stdby
Applications
Bypass
Vout3
BIAS
■
Headphone amplifier
Mobile phone
■ PDA, portable audio player
■
Vout2
Vin2
Gnd
Description
The TS4909 is a stereo audio amplifier designed
to drive headphones in portable applications.
The integrated phantom ground is a circuit
topology that eliminates the heavy output coupling
capacitors. This is of primary importance in
portable applications where space constraints are
very high. A single-ended configuration is also
available, offering even lower power consumption
because the phantom ground can be switched off.
September 2007
Pop-and-click noise during switch-on and switchoff phases is eliminated by integrated circuitry.
Specially designed for applications requiring low
power supplies, the TS4909 is capable of
delivering 31mW of continuous average power
into a 32Ω load with less than 1% THD+N from a
3V power supply.
Featuring an active low standby mode, the
TS4909 reduces the supply current to only 10nA
(typ.). The TS4909 is unity gain stable and can be
configured by external gain-setting resistors.
Rev 8
1/32
www.st.com
32
Contents
TS4909
Contents
1
Typical application schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 4
3
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.1
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.2
Frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3
Gain using the typical application schematics . . . . . . . . . . . . . . . . . . . . . 23
4.4
Power dissipation and efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.4.1
Single-ended configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.4.2
Phantom ground configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.4.3
Total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.5
Decoupling of the circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.6
Wake-up time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.7
Pop performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.8
Standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2/32
TS4909
1
Typical application schematics
Typical application schematics
Figure 1.
Typical applications for the TS4909
Rfeed1
20k
Vcc
Cs
1µF
Phantom ground configuration
Vin1
Cin1
20k
330nF
Rin1
SE/PHG
Vout1
Standby
Vout3
Cb
BIAS
1µF
Vin2
330nF
Cin2
20k
Vout2
Rin2
Gnd
20k
Rfeed2
Rfeed1
20k
Vcc
Cs
Single-ended configuration
Vin1
Cin1
330nF
1µF
SE/PHG
20k
Vout1
Rin1
Cout1
Standby
Vout3
BIAS
Cb
1µF
Vin2
330nF
Cin2
Cout2
20k
Vout2
Rin2
Gnd
20k
Rfeed2
Table 1.
Application component information
Component
Functional description
Rin1,2
Inverting input resistor that sets the closed loop gain in conjunction with Rfeed. This
resistor also forms a high pass filter with Cin (fc = 1 / (2 x Pi x Rin x Cin)).
Cin1,2
Input coupling capacitor that blocks the DC voltage at the amplifier’s input terminal.
Rfeed1,2
Feedback resistor that sets the closed loop gain in conjunction with Rin.
AV= closed loop gain = -Rfeed/Rin.
Cb
Half supply bypass capacitor.
Cs
Supply bypass capacitor that provides power supply filtering.
3/32
Absolute maximum ratings and operating conditions
2
TS4909
Absolute maximum ratings and operating conditions
Table 2.
Absolute maximum ratings
Symbol
VCC
Vi
Tstg
Tj
Rthja
Parameter
Value
Unit
6
V
-0.3V to VCC +0.3V
V
-65 to +150
°C
Maximum junction temperature
150
°C
Thermal resistance junction to ambient DFN10
120
°C/W
1.79
W
2
kV
Supply voltage (1)
Input voltage
Storage temperature
(2)
Pdiss
Power dissipation
DFN10
ESD
Human body model (pin to pin)
ESD
Machine model
220pF - 240pF (pin to pin)
200
V
Latch-up
Latch-up immunity (all pins)
200
mA
Lead temperature (soldering, 10 sec)
260
°C
170 (3)
mA
Output current
1. All voltage values are measured with respect to the ground pin.
2. Pd is calculated with Tamb = 25°C, Tjunction = 150°C.
3. Caution: this device is not protected in the event of abnormal operating conditions, such as for example,
short-circuiting between any one output pin and ground, between any one output pin and VCC, and
between individual output pins.
Table 3.
Operating conditions
Symbol
VCC
RL
Toper
CL
VSTBY
Parameter
Supply voltage
Load resistor
Operating free air temperature range
Load capacitor
RL = 16 to 100Ω
RL > 100Ω
Standby voltage input
TS4909 in STANDBY
TS4909 in active state
Value
Unit
2.2 to 5.5
V
≥ 16
Ω
-40 to + 85
°C
400
100
pF
GND ≤ VSTBY ≤ 0.4 (1)
1.35V ≤ VSTBY ≤ VCC
V
VSE/PHG
Single-ended or phantom ground configuration
voltage Input
TS4909 outputs in single-ended configuration
TS4909 outputs in phantom ground configuration
VSE/PHG=VCC
VSE/PHG=0
Rthja
Thermal resistance junction to ambient DFN10(2)
41
1. The minimum current consumption (ISTBY) is guaranteed at ground for the whole temperature range.
2. When mounted on a 4-layer PCB.
4/32
V
°C/W
TS4909
Electrical characteristics
3
Electrical characteristics
Table 4.
Electrical characteristics at VCC = +5V with GND = 0V and Tamb = 25°C
(unless otherwise specified)
Symbol
Parameter
ICC
Supply current
ISTBY
Standby
current
Pout
THD+N
PSRR
Iout
VO
SNR
Crosstalk
Test conditions
2.1
3.1
3.2
4.8
mA
No input signal, RL=32Ω
10
1000
nA
RL = 32Ω,
RL = 16Ω,
RL = 32Ω,
RL = 16Ω,
single-ended
single-ended
phantom ground
phantom ground
60
95
60
95
Pout = 60mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 90mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 60mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Pout = 90mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Inputs grounded(1), Av = -1, RL>=16Ω, Cb=1μF, F = 217Hz,
V
Power supply
ripple = 200mVpp
rejection ratio
Single-ended output referenced to phantom ground
Single-ended output referenced to ground
Max output
current
Typ. Max. Unit
No input signal, no load, single-ended
No input signal, no load, phantom ground
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Output power
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Total
harmonic
distortion +
noise
(Av=-1)
Min.
66
61
THD +N ≤ 1%, RL = 16Ω connected between out and VCC/2
VOL: RL = 32Ω
VOH: RL = 32Ω
Output swing
VOL: RL = 16Ω
VOH: RL = 16Ω
Signal-tonoise ratio
A-weighted, Av=-1, RL = 32Ω, THD +N < 0.4%,
20Hz ≤ F ≤20kHz
Single-ended
Phantom ground
Channel
separation
RL = 32Ω, Av=-1, phantom ground
F = 1kHz
F = 20Hz to 20kHz
RL = 32Ω, Av=-1, single-ended
F = 1kHz
F = 20Hz to 20kHz
VOO
Output offset
voltage
Phantom ground configuration, floating inputs, Rfeed=22KΩ
tWU
Wake-up time
Phantom ground configuration
Single-ended configuration
88
158
85
150
mW
0.3
0.3
0.3
0.3
%
dB
72
67
140
4.39
4.17
0.14
4.75
0.25
4.55
mA
0.47
0.69
V
dB
104
105
-73
-68
dB
-110
-90
5
20
mV
50
100
80
160
ms
1. Guaranteed by design and evaluation.
5/32
Electrical characteristics
Table 5.
Electrical characteristics at VCC = +3.0V
with GND = 0V, Tamb = 25°C (unless otherwise specified) (1)
Symbol
Parameter
ICC
Supply current
ISTBY
Standby
current
Pout
Iout
VO
SNR
Crosstalk
Test conditions
Min.
2
2.8
2.8
4.2
mA
No input signal, RL=32Ω
10
1000
nA
RL = 32Ω,
RL = 16Ω,
RL = 32Ω,
RL = 16Ω,
single-ended
single-ended
phantom ground
phantom ground
Output swing
64
59
THD +N ≤ 1%, RL = 16Ω connected between out and VCC/2
VOL: RL = 32Ω
VOH: RL = 32Ω
VOL: RL = 16Ω
VOH: RL = 16Ω
Signal-tonoise ratio
A-weighted, Av=-1, RL = 32Ω, THD +N < 0.4%, 20Hz ≤F ≤
20kHz
Single-ended
Phantom ground
Channel
separation
RL = 32Ω, Av=-1, phantom ground
F = 1kHz
F = 20Hz to 20kHz
RL = 32Ω, Av=-1, single-ended
F = 1kHz
F = 20Hz to 20kHz
VOO
Output offset
voltage
Phantom ground configuration, floating inputs, Rfeed=22KΩ
tWU
Wake-up time
Phantom ground configuration
Single-ended configuration
1. All electrical values are guaranteed with correlation measurements at 2.6V and 5V.
2. Guaranteed by design and evaluation.
6/32
20
30
20
30
Pout = 25mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 40mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 25mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Pout = 40mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Inputs grounded (2), Av=-1, RL>=16Ω, Cb=1μF, F = 217Hz,
Power supply Vripple = 200mVpp
rejection ratio
Single-ended output referenced to phantom ground
Single-ended output referenced to ground
Max output
current
Typ. Max. Unit
No input signal, no load, single-ended
No input signal, no load, phantom ground
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Output power
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Total harmonic
distortion +
THD+N
noise
(Av=-1)
PSRR
TS4909
31
52
31
54
mW
0.3
0.3
0.3
0.3
%
dB
70
65
82
2.6
2.45
0.12
2.83
0.19
2.70
mA
0.34
0.49
V
dB
100
101
-73
-68
dB
-110
-90
5
20
mV
50
100
80
160
ms
TS4909
Table 6.
Electrical characteristics
Electrical characteristics at VCC = +2.6V
with GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Parameter
ICC
Supply
current
No input signal, no load, single-ended
No input signal, no load, phantom ground
1.9
2.8
2.7
4
mA
ISTBY
Standby
current
No input signal, RL=32Ω
10
1000
nA
Pout
THD+N
PSRR
Iout
VO
SNR
Crosstalk
VOO
tWU
Test conditions
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Output power
THD+N = 1% max, F = 1kHz, RL = 32Ω,
THD+N = 1% max, F = 1kHz, RL = 16Ω,
Total
harmonic
distortion +
noise
(Av=-1)
RL = 32Ω,
RL = 16Ω,
RL = 32Ω,
RL = 16Ω,
Min.
single-ended
single-ended
phantom ground
phantom ground
Pout = 20mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 30mW, 20Hz ≤ F ≤ 20kHz, single-ended
Pout = 20mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Pout = 30mW, 20Hz ≤ F ≤ 20kHz, phantom ground
Inputs grounded (1), Av=-1, RL>=16Ω, Cb=1μF, F = 217Hz,
Power supply Vripple = 200mVpp
rejection ratio
Single-ended output referenced to phantom ground
Single-ended output referenced to ground
Max output
current
64
59
THD +N ≤1%, RL = 16Ω connected between out and VCC/2
VOL: RL = 32Ω
V : R = 32Ω
Output swing OH L
VOL: RL = 16Ω
VOH: RL = 16Ω
Signal-tonoise ratio
A weighted, Av=-1, RL = 32Ω, THD +N < 0.4%,
20Hz ≤ F ≤ 20kHz
Single-ended
Phantom ground
Channel
separation
RL = 32Ω, Av=-1, phantom ground
F = 1kHz
F = 20Hz to 20kHz
RL = 32Ω, Av=-1, single-ended
F = 1kHz
F = 20Hz to 20kHz
Output offset
Phantom ground configuration, floating inputs, Rfeed=22KΩ
voltage
Wake-up
time
15
22
15
22
Phantom ground configuration
Single-ended configuration
Typ. Max. Unit
23
38
23
39
mW
0.3
0.3
0.3
0.3
%
dB
70
65
70
2.25
2.11
mA
0.11 0.3
2.45
0.18 0.44
2.32
V
dB
99
100
-73
-68
dB
-110
-90
5
20
mV
50
100
80
160
ms
1. Guaranteed by design and evaluation.
7/32
Electrical characteristics
Table 7.
TS4909
Index of graphics
Description
Open-loop frequency response
Output swing vs. power supply voltage
Figure 2 to 6
Figure 7
THD+N vs. output power
Figure 8 to 23
THD+N vs. frequency
Figure 24 to 31
Output power vs. power supply voltage
Figure 32 to 35
Output power vs. load resistance
Figure 36 to 41
Power dissipation vs. output power
Figure 42 to 47
Crosstalk vs. frequency
Figure 48 to 53
Signal to noise ratio vs. power supply voltage
Figure 54 to 61
Power supply rejection ratio vs. frequency
Figure 62 to 67
Current consumption vs. power supply voltage
Current consumption vs. standby voltage
Power derating curves
8/32
Figure
Figure 68 and 69
Figure 70 to 75
Figure 76
TS4909
Electrical characteristics
Figure 2.
Open-loop frequency response
Figure 3.
Open-loop frequency response
90
100
125
45
75
100
0
50
0
75
-45
25
-45
50
-90
0
-90
25
-135
0
-180
-50
-25
-225
-75
150
90
gain
45
RL=1M Ω , T AMB=25°C
-50
-1
10
10
10
3
10
-270
5
10
-25
-135
phase
-180
10
Frequency (Hz)
Figure 4.
-225
RL=100 Ω , CL=400pF, T AMB =25°C
-100
-1
10
7
Phase (°)
Gain (dB)
phase
Phase (°)
Gain (dB)
gain
10
3
10
-270
5
10
7
Frequency (Hz)
Open-loop frequency response
150
Figure 5.
90
100
45
75
Open-loop frequency response
90
gain
125
45
0
25
-45
50
-90
Gain (dB)
25
-135
0
-180
-25
10
10
3
0
10
10
-25
-135
-50
-180
-75
-270
5
-90
phase
-225
RL=1M Ω , CL=100pF, T AMB=25°C
-50
-1
10
Gain (dB)
50
-45
phase
Phase (°)
0
75
100
10
Frequency (Hz)
Figure 6.
-225
RL=16 Ω , T AMB =25°C
-100
-1
10
7
Phase (°)
gain
10
3
10
-270
5
10
7
Frequency (Hz)
Open-loop frequency response
Figure 7.
Output swing vs. power supply
voltage
6
100
90
75
45
T AMB =25°C
5
25
-45
0
-90
phase
-25
-135
-50
-75
-100
-1
10
VOH & VOL (V)
0
Phase (°)
Gain (dB)
gain
50
4
3
RL=32Ω
2
RL=16Ω
-180
-225
RL=16 Ω , CL=400pF, TAMB=25°C
10
10
3
Frequency (Hz)
10
5
1
-270
10
7
0
2
3
4
5
6
Power Supply Voltage (V)
9/32
Electrical characteristics
Figure 8.
TS4909
THD+N vs. output power
Figure 9.
10
10
Phantom Ground
F=1kHz, RL=16Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Phantom Ground
F=20kHz, RL=16 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
1
THD+N vs. output power
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
1
Vcc=3V
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
Output Power (mW)
Figure 10. THD+N vs. output power
0.2
0.1
0.2
0.1
0.2
10
Phantom Ground
F=1kHz, RL=32Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Phantom Ground
F=20kHz, RL=32 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
THD+N (%)
THD+N (%)
0.1
Figure 11. THD+N vs. output power
10
1
0.01
Output Power (mW)
Vcc=5V
0.1
Vcc=3V
1
Vcc=5V
Vcc=3V
Vcc=2.6V
0.1
Vcc=2.6V
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
Output Power (mW)
Figure 12. THD+N vs. output power
Figure 13. THD+N vs. output power
10
10
Single Ended
F=1kHz, RL=16 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Single Ended
F=20kHz, RL=16 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
1
0.01
Output Power (mW)
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
1
Vcc=3V
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
Output Power (mW)
10/32
0.1
0.2
0.01
1E-3
0.01
Output Power (mW)
TS4909
Electrical characteristics
Figure 14. THD+N vs. output power
Figure 15. THD+N vs. output power
10
Single Ended
F=20kHz, RL=32 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
THD+N (%)
THD+N (%)
1
10
Single Ended
F=1kHz, RL=32 Ω
Av=-1, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
0.1
Vcc=3V
1
Vcc=5V
Vcc=3V
Vcc=2.6V
0.1
Vcc=2.6V
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
Output Power (mW)
Figure 16. THD+N vs. output power
0.2
0.1
0.2
0.1
0.2
10
Phantom Ground
F=1kHz, RL=16 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Phantom Ground
F=20kHz, RL=16 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
0.1
Figure 17. THD+N vs. output power
10
1
0.01
Output Power (mW)
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
Vcc=3V
1
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
Output Power (mW)
Figure 18. THD+N vs. output power
Figure 19. THD+N vs. output power
10
10
Phantom Ground
F=1kHz, RL=32 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Phantom Ground
F=20kHz, RL=32 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
1
0.01
Output Power (mW)
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
1
Vcc=3V
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
Output Power (mW)
0.1
0.2
0.01
1E-3
0.01
Output Power (mW)
11/32
Electrical characteristics
TS4909
Figure 20. THD+N vs. output power
Figure 21. THD+N vs. output power
10
Single Ended
F=20kHz, RL=16 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
1
10
Single Ended
F=1kHz, RL=16 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
1
Vcc=3V
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
0.01
Output Power (mW)
Figure 22. THD+N vs. output power
0.1
0.2
10
Single Ended
F=1kHz, RL=32 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Single Ended
F=20kHz, RL=32 Ω
Av=-4, Tamb=25°C
BW=20Hz-120kHz
Vcc=5V
THD+N (%)
THD+N (%)
0.2
Figure 23. THD+N vs. output power
10
1
0.1
Output Power (mW)
Vcc=3V
0.1
Vcc=2.6V
Vcc=5V
1
Vcc=3V
Vcc=2.6V
0.1
0.01
1E-3
1E-3
0.01
0.1
0.01
1E-3
0.2
0.01
Output Power (mW)
Output Power (mW)
Figure 24. THD+N vs. frequency
Figure 25. THD+N vs. frequency
1
1
0.1
Vcc=2.6V
Po=30mW
Phantom Ground
RL=32Ω , Av=-1
BW=20Hz-120kHz
T AMB =25°C
Vcc=3V
Po=40mW
THD+N (%)
THD+N (%)
Phantom Ground
RL=16Ω , Av=-1
BW=20Hz-120kHz
TAMB =25°C
Vcc=5V
Po=90mW
0.01
Vcc=2.6V
Po=20mW
0.01
0.002
Vcc=3V
Po=25mW
0.002
20
100
1k
Frequency (Hz)
12/32
Vcc=5V
Po=60mW
0.1
10k
20k
20
100
1k
Frequency (Hz)
10k
20k
TS4909
Electrical characteristics
Figure 26. THD+N vs. frequency
Figure 27. THD+N vs. frequency
1
1
Single Ended
RL=32Ω , Av=-1
BW=20Hz-120kHz
T AMB =25°C
Vcc=5V
Po=90mW
0.1
THD+N (%)
THD+N (%)
Single Ended
RL=16Ω , Av=-1
BW=20Hz-120kHz
TAMB =25°C
Vcc=3V
Po=40mW
Vcc=2.6V
Po=30mW
0.01
0.1
Vcc=2.6V
Po=20mW
0.01
0.002
Vcc=3V
Po=25mW
0.002
20
100
1k
10k
20k
20
100
Frequency (Hz)
1k
10k
20k
10k
20k
Frequency (Hz)
Figure 28. THD+N vs. frequency
Figure 29. THD+N vs. frequency
1
1
Phantom Ground
RL=16Ω , Av=-4
BW=20Hz-120kHz
TAMB =25°C
Phantom Ground
RL=32Ω , Av=-4
BW=20Hz-120kHz
T AMB =25°C
Vcc=5V
Po=90mW
THD+N (%)
THD+N (%)
Vcc=5V
Po=60mW
0.1
Vcc=2.6V
Po=30mW
Vcc=3V
Po=40mW
Vcc=5V
Po=60mW
0.1
Vcc=2.6V
Po=20mW
Vcc=3V
Po=25mW
0.01
0.01
0.005
0.002
20
100
1k
10k
20k
20
100
Frequency (Hz)
Figure 30. THD+N vs. frequency
Figure 31. THD+N vs. frequency
1
1
Single Ended
RL=16Ω , Av=-4
BW=20Hz-120kHz
TAMB =25°C
Single Ended
RL=32Ω , Av=-4
BW=20Hz-120kHz
T AMB =25°C
Vcc=5V
Po=90mW
THD+N (%)
THD+N (%)
1k
Frequency (Hz)
Vcc=3V
Po=40mW
0.1
Vcc=2.6V
Po=30mW
0.1
Vcc=5V
Po=60mW
Vcc=3V
Po=25mW
Vcc=2.6V
Po=20mW
0.01
0.01
0.005
0.002
20
100
1k
Frequency (Hz)
10k
20k
20
100
1k
10k
20k
Frequency (Hz)
13/32
Electrical characteristics
TS4909
Figure 32. Output power vs. power supply
voltage
Figure 33. Output power vs. power supply
voltage
240
140
Output Power (mW)
200
Output Power (mW)
Phantom Ground
RL=16 Ω , F=1kHz
Av=-1, T AMB =25°C
BW=20Hz-120kHz
160
120
THD+N=10%
80
THD+N=1%
40
0
2
3
4
120
Phantom Ground
RL=32 Ω , F=1kHz
Av=-1, T AMB =25°C
100
BW=20Hz-120kHz
80
60
THD+N=10%
40
THD+N=1%
20
5
0
6
2
3
Power Supply Voltage (V)
Figure 34. Output power vs. power supply
voltage
Output Power (mW)
Output Power (mW)
BW=20Hz-120kHz
160
120
THD+N=10%
80
THD+N=1%
40
2
3
4
120
Single Ended
RL=32 Ω , F=1kHz
Av=-1, T AMB =25°C
100
BW=20Hz-120kHz
80
60
THD+N=10%
40
THD+N=1%
20
5
0
6
2
3
Power Supply Voltage (V)
5
6
Figure 37. Output power vs. load resistance
50
50
Phantom Ground
Vcc=2.6V, F=1kHz
Av=-1, T AMB =25°C
BW=20Hz-120kHz
30
THD+N=1%
20
10
Single Ended
Vcc=2.6V, F=1kHz
Av=-1, T AMB=25°C
THD+N=10%
40
Output Power (mW)
THD+N=10%
40
0
16
4
Power Supply Voltage (V)
Figure 36. Output power vs. load resistance
Output Power (mW)
6
140
Single Ended
RL=16 Ω , F=1kHz
Av=-1, T AMB=25°C
200
BW=20Hz-120kHz
30
THD+N=1%
20
10
32
48
64
Load Resistance (Ω )
14/32
5
Figure 35. Output power vs. power supply
voltage
240
0
4
Power Supply Voltage (V)
80
96
0
16
32
48
64
Load Resistance (Ω )
80
96
TS4909
Electrical characteristics
Figure 38. Output power vs. load resistance
Figure 39. Output power vs. load resistance
80
Phantom Ground
Vcc=3V, F=1kHz
Av=-1, T AMB=25°C
60
THD+N=10%
40
Output Power (mW)
Output Power (mW)
80
BW=20Hz-120kHz
THD+N=1%
20
60
THD+N=10%
40
BW=20Hz-120kHz
THD+N=1%
20
0
16
32
48
64
80
0
16
96
32
48
Load Resistance (Ω )
64
80
96
Load Resistance (Ω )
Figure 40. Output power vs. load resistance
Figure 41. Output power vs. load resistance
200
200
150
Output Power (mW)
Phantom Ground
Vcc=5V, F=1kHz
Av=-1, T AMB=25°C
THD+N=10%
Output Power (mW)
Single Ended
Vcc=3V, F=1kHz
Av=-1, T AMB=25°C
BW=20Hz-120kHz
THD+N=1%
100
50
Single Ended
Vcc=5V, F=1kHz
Av=-1, T AMB=25°C
THD+N=10%
150
BW=20Hz-120kHz
THD+N=1%
100
50
0
16
32
48
64
80
0
16
96
32
Load Resistance (Ω )
48
64
80
96
Load Resistance (Ω )
Figure 42. Power dissipation vs. output power Figure 43. Power dissipation vs. output power
80
30
Power Dissipation (mW)
70
Power Dissipation (mW)
Phantom Ground
Vcc=2.6V, F=1kHz
THD+N<1%
60
50
RL=16Ω
40
30
20
RL=32 Ω
25
RL=16 Ω
20
15
RL=32 Ω
10
5
10
0
Single Ended
Vcc=2.6V, F=1kHz
THD+N<1%
0
5
10
15
20
25
30
Output Power (mW)
35
40
0
0
5
10
15
20
25
30
Output Power (mW)
35
40
15/32
Electrical characteristics
TS4909
Figure 44. Power dissipation vs. output power Figure 45. Power dissipation vs. output power
40
Phantom Ground
Vcc=3V, F=1kHz
THD+N<1%
100
80
RL=16 Ω
60
40
RL=32Ω
20
0
Single Ended
Vcc=3V, F=1kHz
THD+N<1%
35
Power Dissipation (mW)
Power Dissipation (mW)
120
RL=16 Ω
30
25
20
RL=32 Ω
15
10
5
0
10
20
30
40
Output Power (mW)
50
0
60
0
5
10
15
20
25 30 35 40
Output Power (mW)
45
50
55
Figure 46. Power dissipation vs. output power Figure 47. Power dissipation vs. output power
100
Single Ended
Vcc=5V, F=1kHz, THD+N<1%
Phantom Ground
Vcc=5V, F=1kHz
THD+N<1%
250
200
Power Dissipation (mW)
Power Dissipation (mW)
300
RL=16Ω
150
100
RL=32Ω
50
0
0
20
40
60
80
100
120
Output Power (mW)
140
60
RL=32 Ω
40
0
160
0
20
40
60
80
100
120
Output Power (mW)
140
160
Figure 49. Crosstalk vs. frequency
0
0
Single Ended
Vcc=5V, RL=16 Ω
Av=-1, Po=90mW
T AMB =25°C
-40
-60
OUT1 to OUT2
-80
Single Ended
Vcc=5V, RL=32Ω
Av=-1, Po=60mW
TAMB =25°C
-20
Crosstalk (dB)
-20
Crosstalk (dB)
80
20
Figure 48. Crosstalk vs. frequency
OUT2 to OUT1
-100
-40
-60
OUT2 to OUT1
-80
OUT1 to OUT2
-100
-120
20
100
1k
Frequency (Hz)
16/32
RL=16Ω
10k
20k
-120
20
100
1k
Frequency (Hz)
10k
20k
TS4909
Electrical characteristics
Figure 50. Crosstalk vs. frequency
Figure 51. Crosstalk vs. frequency
0
0
Single Ended
Vcc=5V, RL=16 Ω
Av=-4, Po=90mW
T AMB =25°C
-40
Single Ended
Vcc=5V, RL=32Ω
Av=-4, Po=60mW
TAMB =25°C
-20
Crosstalk (dB)
Crosstalk (dB)
-20
-60
OUT1 to OUT2
OUT2 to OUT1
-80
-100
-40
-60
OUT2 to OUT1
-80
OUT1 to OUT2
-100
-120
100
20
1k
10k
-120
20k
20
100
1k
Frequency (Hz)
Figure 52. Crosstalk vs. frequency
0
Phantom ground
Vcc=5V, Av=-1,
T AMB=25°C
-40
RL=16 Ω , Po=90mW
-60
-80
RL=32Ω , Po=60mW
-100
-120
20
Phantom ground
Vcc=5V, Av=-4,
T AMB=25°C
-20
Crosstalk (dB)
Crosstalk (dB)
-20
100
1k
-40
RL=16 Ω , Po=90mW
-60
-80
RL=32 Ω , Po=60mW
-100
10k
-120
20k
20
100
1k
Frequency (Hz)
10k
20k
Frequency (Hz)
Figure 54. Signal to noise ratio vs. power
supply voltage
Figure 55. Signal to noise ratio vs. power
supply voltage
104
106
Unweighted Filter (20Hz-20kHz)
Unweighted Filter (20Hz-20kHz)
Phantom Ground
Av=-1, T AMB =25°C
102
Signal to Noise Ratio (dB)
Signal to Noise Ratio (dB)
20k
Figure 53. Crosstalk vs. frequency
0
Cb=1 μ F
THD+N<0.4%
100
98
RL=16Ω
96
RL=32 Ω
94
92
10k
Frequency (Hz)
Single Ended
Av=-1, T AMB =25°C
104
Cb=1μ F
THD+N<0.4%
102
100
RL=16 Ω
98
RL=32 Ω
96
2
3
4
Power Supply Voltage (V)
5
6
94
2
3
4
5
6
Power Supply Voltage (V)
17/32
Electrical characteristics
TS4909
Figure 56. Signal to noise ratio vs. power
supply voltage
Figure 57. Signal to noise ratio vs. power
supply voltage
108
106
Phantom Ground
A-weighted Filter
Av=-1, T AMB =25°C
104
Cb=1 μ F
THD+N<0.4%
Signal to Noise Ratio (dB)
Signal to Noise Ratio (dB)
108
102
RL=16 Ω
100
RL=32 Ω
98
96
2
3
106
Single Ended
A-weighted Filter
Av=-1, T AMB =25°C
104
Cb=1 μ F
THD+N<0.4%
102
RL=16 Ω
100
RL=32 Ω
98
4
5
96
6
2
3
4
Power Supply Voltage (V)
Figure 58. Signal to noise ratio vs. power
supply voltage
6
Figure 59. Signal to noise ratio vs. power
supply voltage
98
96
Unweighted Filter (20Hz-20kHz)
96
Unweighted Filter (20Hz-20kHz)
Phantom Ground
Av=-4, T AMB =25°C
94
Signal to Noise Ratio (dB)
Signal to Noise Ratio (dB)
5
Power Supply Voltage (V)
Cb=1 μ F
THD+N<0.4%
92
RL=16 Ω
90
88
RL=32Ω
Phantom Ground
Av=-4, T AMB =25°C
94
Cb=1 μ F
THD+N<0.4%
92
RL=16 Ω
90
RL=32 Ω
88
86
84
2
3
4
5
86
6
2
3
Power Supply Voltage (V)
Figure 60. Signal to noise ratio vs. power
supply voltage
98
96
Cb=1 μ F
THD+N<0.4%
Signal to Noise Ratio (dB)
Signal to Noise Ratio (dB)
6
100
Phantom Ground
A-weighted Filter
Av=-4, T AMB =25°C
94
RL=16 Ω
92
RL=32 Ω
90
2
3
4
Power Supply Voltage (V)
18/32
5
Figure 61. Signal to noise ratio vs. power
supply voltage
100
88
4
Power Supply Voltage (V)
98
Phantom Ground
A-weighted Filter
Av=-4, T AMB =25°C
96
Cb=1 μ F
THD+N<0.4%
94
RL=16 Ω
92
RL=32 Ω
90
5
6
88
2
3
4
Power Supply Voltage (V)
5
6
TS4909
Electrical characteristics
Figure 62. Power supply rejection ratio vs.
frequency
Figure 63. Power supply rejection ratio vs.
frequency
0
0
Phantom Ground, Inputs grounded
Av=-1, RL≥ 16Ω , Cb=1μ F, T AMB =25°C
-20
-20
-30
-30
-40
Vcc=2.6V
-50
Vcc=3V
Vcc=5V
-60
Single Ended, Inputs grounded
Av=-1, RL ≥ 16 Ω , Cb=1 μ F, T AMB=25°C
-10
PSRR (dB)
PSRR (dB)
-10
-40
Vcc=2.6V
-50
Vcc=3V
Vcc=5V
-60
-70
-70
-80
20
100
1k
10k
-80
20k
20
100
1k
Frequency (Hz)
Figure 64. Power supply rejection ratio vs.
frequency
20k
Figure 65. Power supply rejection ratio vs.
frequency
0
0
Phantom Ground, Inputs grounded
Vcc=3V, RL≥ 16Ω , Cb=1μ F, T AMB =25°C
-10
Single Ended, Inputs grounded
Vcc=3V, RL ≥ 16 Ω , Cb=1 μ F, T AMB =25°C
-10
-20
-20
Av=-4
Av=-4
-30
PSRR (dB)
PSRR (dB)
10k
Frequency (Hz)
Av=-2
-40
Av=-1
-50
-30
Av=-2
-40
-50
-60
-60
-70
-70
-80
20
100
1k
10k
Av=-1
-80
20k
20
100
1k
Frequency (Hz)
10k
20k
Frequency (Hz)
Figure 66. Power supply rejection ratio vs.
frequency
Figure 67. Power supply rejection ratio vs.
frequency
0
0
Phantom Ground, Inputs grounded
Av=-1, RL≥ 16Ω , Vcc=3V, T AMB =25°C
-10
Single Ended, Inputs grounded
Av=-1, RL ≥ 16 Ω , Vcc=3V, T AMB =25°C
-10
-20
-20
Cb=1 μ F
PSRR (dB)
PSRR (dB)
Cb=1μ F
-30
Cb=470nF
-40
Cb=220nF
-50
Cb=100nF
-30
-60
-70
-70
20
100
1k
Frequency (Hz)
10k
20k
Cb=220nF
Cb=100nF
-50
-60
-80
Cb=470nF
-40
-80
20
100
1k
10k
20k
Frequency (Hz)
19/32
Electrical characteristics
TS4909
Figure 68. Current consumption vs. power
supply voltage
Figure 69. Current consumption vs. power
supply voltage
4.0
3.0
Current Consumption (mA)
Current Consumption (mA)
3.5
3.0
2.5
2.0
T AMB =85°C
1.5
T AMB=25°C
1.0
TAMB =-40°C
0.5
0.0
2
3
Phantom ground
No Loads
4
5
2.5
2.0
1.5
1.0
T AMB=85°C
T AMB =25°C
0.5
Single ended
No Loads
T AMB=-40°C
0.0
6
2
3
Power Supply Voltage (V)
4
5
6
Power Supply Voltage (V)
Figure 70. Current consumption vs. standby
voltage
Figure 71. Current consumption vs. standby
voltage
4
2.5
Current Consumption (mA)
Current Consumption (mA)
T AMB =85°C
T AMB =85°C
3
T AMB =25°C
2
T AMB =-40°C
1
2.0
TAMB =25°C
1.5
T AMB =-40°C
1.0
0.5
Phantom ground
V CC =2.6V
0
0.0
0.5
1.0
1.5
2.0
0.0
0.0
2.5
Single ended
V CC =2.6V
0.5
Standby Voltage (V)
1.0
1.5
2.0
2.5
Standby Voltage (V)
Figure 72. Current consumption vs. standby
voltage
Figure 73. Current consumption vs. standby
voltage
2.5
4
Current Consumption (mA)
Current Consumption (mA)
T AMB=85°C
T AMB=85°C
3
T AMB =25°C
TAMB =-40°C
2
1
2.0
T AMB =25°C
TAMB =-40°C
1.5
1.0
0.5
Phantom ground
V CC =3V
0
0.0
0.5
1.0
1.5
2.0
Standby Voltage (V)
20/32
2.5
3.0
0.0
0.0
Single ended
V CC =3V
0.5
1.0
1.5
2.0
Standby Voltage (V)
2.5
3.0
TS4909
Electrical characteristics
Figure 74. Current consumption vs. standby
voltage
Figure 75. Current consumption vs. standby
voltage
8
8
6
Current Consumption (mA)
Current Consumption (mA)
T AMB =85°C
T AMB =25°C
T AMB =-40°C
4
2
T AMB =85°C
6
T AMB=25°C
TAMB =-40°C
4
2
Phantom ground
V CC=5V
0
0.0
0.5
1.0
1.5
2.0
4
5
Standby Voltage (V)
0
0.0
Single ended
V CC =5V
0.5
1.0
1.5
2.0
4
5
Standby Voltage (V)
DFN10 Package Power Dissipation (W)
Figure 76. Power derating curves
3.5
3.0
Mounted on a 4-layer PCB
2.5
No Heat sink
2.0
1.5
1.0
0.5
0.0
0
25
50
75
100
125
150
Ambiant Temperature (° C )
21/32
Application information
TS4909
4
Application information
4.1
General description
The TS4909 integrates two monolithic power amplifiers. The amplifier output can be
configured to provide either single-ended (SE) capacitively-coupled output or phantom
ground (PHG) capacitor-less output. Figure 1: Typical applications for the TS4909 on page 3
shows schematics for each of these configurations.
Single-ended configuration
In the single-ended configuration, an output coupling capacitor, Cout, on the output of the
power amplifier (Vout1 and Vout2) is mandatory. The output of the power amplifier is biased to
a DC voltage equal to VCC/2 and the output coupling capacitor blocks this reference voltage.
Phantom ground configuration
In the phantom ground configuration, an internal buffer (Vout3) maintains the VCC/2 voltage
and the output of the power amplifiers are also biased to the VCC/2 voltage. Therefore, no
output coupling capacitors are needed. This is of primary importance in portable
applications where space constraints are continually present.
4.2
Frequency response
Higher cut-off frequency
In the high frequency region, you can limit the bandwidth by adding a capacitor Cfeed in
parallel with Rfeed. It forms a low-pass filter with a -3dB cut-off frequency FCH. Assuming
that FCH is the highest frequency to be amplified (with a 3dB attenuation), the maximum
value of Cfeed is:
1
F CH = -------------------------------------------------2π ⋅ R feed ⋅ C feed
Figure 77. Higher cut-off frequency vs. feedback capacitor
Higher Cut-off Frequency (kHz)
100k
Rfeed=10kΩ
Rfeed=40kΩ
1k
Rfeed=80k Ω
100
0.01
22/32
Rfeed=20kΩ
10k
0.1
1
Cfeed (μ F )
10
100
TS4909
Application information
Lower cut-off frequency
The lower cut-off frequency FCL of the TS4909 depends on input capacitors Cin1,2. In the
single-ended configuration, FCL depends on output capacitors Cout1,2 as well.
The input capacitor Cin in series with the input resistor Rin of the amplifier is equivalent to a
first-order high-pass filter. Assuming that FCL is the lowest frequency to be amplified (with a
3dB attenuation), the minimum value of Cin is:
1
C in = --------------------------------------2π ⋅ F CL ⋅ R in
In the single-ended configuration, the capacitor Cout in series with the load resistor RL is
equivalent to a first-order high-pass filter. Assuming that FCL is the lowest frequency to be
amplified (with a 3dB attenuation), the minimum value of Cout is:
1
C out = -------------------------------------2π ⋅ F CL ⋅ R L
Figure 78. Lower cut-off frequency vs. input
capacitor
Figure 79. Lower cut-off frequency vs. output
capacitor
10k
10k
R L=16 Ω
Lower Cut-off frequency (Hz)
Lower Cut-off frequency (Hz)
Rin=10kΩ
Rin=20kΩ
1k
Rin=50kΩ
Rin=100kΩ
100
10
1
10
100
1000
R L=32 Ω
1k
R L=300 Ω
R L=600 Ω
100
10
0.1
1
Cin (nF)
10
Cout (μ F )
100
1000
Note:
If FCL is kept the same for calculation purposes, it must be taken in account that the 1storder high-pass filter on the input and the 1st-order high-pass filter on the output create a
2nd-order high-pass filter in the audio signal path with an attenuation 6dB on FCL and a rolloff of 40db ⁄ decade.
4.3
Gain using the typical application schematics
In the flat region (no Cin effect), the output voltage of a channel is:
R feed⎞
V OUT = V IN ⋅ ⎛ – ------------- = V IN ⋅ A V
⎝ R ⎠
in
The gain AV is:
R feed
A V = – ------------R in
Note:
The configuration (either single-ended or phantom ground) has no effect on the value of the
gain.
23/32
Application information
4.4
TS4909
Power dissipation and efficiency
Hypotheses:
●
Voltage and current (Vout and Iout) in the load are sinusoidal.
●
Supply voltage (VCC) is a pure DC source.
Regarding the load we have:
V OUT = V PEAK sin ωt ( V )
and
V OUT
I OUT = -------------- ( A )
RL
and
2
V PEAK
P OUT = ----------------- ( A )
2R L
4.4.1
Single-ended configuration
The average current delivered by the power supply voltage is:
π
Icc AVG
V PEAK
V PEAK
1
= ------ ∫ ----------------- sin ( t ) dt = ----------------- ( A )
RL
πR L
2π
0
Figure 80. Current delivered by power supply voltage in single-ended configuration
Icc (t)
Vpeak/RL
IccAVG
0
T/2
T
2T Time
3T/2
The power delivered by the power supply voltage is:
P supply = V CC I CC
AVG
(W)
Therefore, the power dissipation by each power amplifier is
P diss = P supply – P OUT ( W )
2V CC
P diss = ------------------- P OUT – P OUT ( W )
π RL
and the maximum value is obtained when:
∂P diss
= 0
∂P OUT
24/32
TS4909
Application information
and its value is:
2
P diss
Note:
MAX
V CC
-(W)
= -----------2
π RL
This maximum value depends only on the power supply voltage and load values.
The efficiency is the ratio between the output power and the power supply:
P OUT
πV PEAK
η = ------------------ = -------------------P supply
2V CC
The maximum theoretical value is reached when VPEAK = VCC/2, so:
η = --π- = 78.5%
4
4.4.2
Phantom ground configuration
The average current delivered by the power supply voltage is:
π
Icc AVG
2V PEAK
1 V PEAK
= --- ∫ ----------------- sin ( t ) dt = --------------------- ( A )
π
RL
πR L
0
Figure 81. Current delivered by power supply voltage in phantom ground
configuration
Icc (t)
Vpeak/RL
IccAVG
0
T/2
T
2T Time
3T/2
The power delivered by the power supply voltage is:
P supply = V CC I CC
AVG
(W)
Therefore, the power dissipation by each amplifier is
2 2V CC
P diss = ---------------------- P OUT – P OUT ( W )
π RL
and the maximum value is obtained when:
∂P diss
= 0
∂ P OUT
and its value is:
2
P diss
Note:
MAX
2V CC
-(W)
= -------------2
π RL
This maximum value depends only on power supply voltage and load values.
25/32
Application information
TS4909
The efficiency is the ratio between the output power and the power supply:
P OUT
πV PEAK
η = ------------------ = -------------------P supply
4V CC
The maximum theoretical value is reached when VPEAK = VCC/2, so:
η = --π- = 39.25%
8
4.4.3
Total power dissipation
The TS4909 is a stereo (dual channel) amplifier. It has two independent power amplifiers.
Each amplifier produces heat due to its power dissipation. Therefore the maximum die
temperature is the sum of each amplifier’s maximum power dissipation. It is calculated as
follows:
●
Pdiss 1 = power dissipation due to the first channel power amplifier (Vout1).
●
Pdiss 2 = power dissipation due to the second channel power amplifier (Vout2).
●
Total Pdiss = Pdiss 1 + Pdiss 2 (W)
In most cases, Pdiss 1 = Pdiss 2, giving:
TotalPdiss = 2Pdiss1 = 2P diss2
Single-ended configuration:
2 2V CC
TotalP diss = ---------------------- P OUT – 2P OUT
π RL
Phantom ground configuration:
4 2V CC
TotalP diss = ---------------------- P OUT – 2P OUT
π RL
4.5
Decoupling of the circuit
Two capacitors are needed to properly bypass the TS4909 — a power supply capacitor Cs
and a bias voltage bypass capacitor Cb.
Cs has a strong influence on the THD+N at high frequencies (above 7kHz) and indirectly on
the power supply disturbances. With 1 μF, you could expect the THD+N performance to be
similar to the values shown in this datasheet. If Cs is lower than 1 μF, THD+N increases at
high frequencies and disturbances on the power supply rail are less filtered. On the contrary,
if Cs is higher than 1 μF, those disturbances on the power supply rail are more filtered.
Cb has an influence on THD+N at lower frequencies, but its value is critical on the final result
of PSRR with inputs grounded in lower frequencies:
26/32
●
If Cb is lower than 1 μF, THD+N increases at lower frequencies and the PSRR worsens
(increases).
●
If Cb is higher than 1 μF, the benefit on THD+N and PSRR in the lower frequency range
is small.
TS4909
4.6
Application information
Wake-up time
When the standby is released to turn the device ON, the bypass capacitor Cb is charged
immediately. As Cb is directly linked to the bias of the amplifier, the bias will not work
properly until the Cb voltage is correct. The time to reach this voltage plus a time delay of
40ms (pop precaution) is called the wake-up time or tWU. It is specified in the electrical
characteristics tables with Cb=1µF (see Section 3: Electrical characteristics on page 5).
If Cb has a value other than 1µF, you can calculate tWU by using the following formulas, or
read it directly from the graph in Figure 82.
●
Single-ended configuration
Cb ⋅ 2.5
t WU = ----------------------- + 40
0.042
●
[ms;μF ]
Phantom ground configuration
Cb ⋅ 2.5
t WU = ----------------------- + 40
0.417
[ms;μF ]
Figure 82. Typical wake-up time vs. bypass capacitance
350
T AMB=25°C
300
Wake-up Time (ms)
Single Ended
250
200
150
Phantom Ground
100
50
0
0
1
2
3
4
5
Cb (μ F )
Note:
It is assumed the Cb voltage is equal to 0 V. If the Cb voltage is not equal 0 V, the wake-up
time is lower.
4.7
Pop performance
Pop performance in the phantom ground configuration is closely linked with the size of the
input capacitor Cin. The size of Cin is dependent on the lower cut-off frequency and PSRR
values requested.
In order to reach low pop, Cin must be charged to VCC/2 in less than 40ms. To follow this
rule, the equivalent input constant time (RinCin) should be less then 8ms:
τ in = Rin x Cin < 0.008 s
By following the previous rules, the TS4909 can reach low pop even with a high gain such as
20dB.
27/32
Application information
TS4909
Example calculation:
With Rin = 20kΩ and FCL = 20Hz, -3db low cut-off frequency, Cin = 398nF. So, Cin = 390nF
with standard value which gives a lower cut-off frequency equal to 20.4Hz.
In this case,
τ in = Rin x Cin = 7.8ms
This value is sufficient with regards to the previous formula, so we can state that the pop will
be imperceptible.
Connecting the headphones
Generally headphones are connected using a jack connector. To prevent pop in the
headphones while plugging in the jack, a pulldown resistor should be connected in parallel
with each headphone output. This allows the capacitors Cout to be charged even when no
headphones are plugged in.
A resistor of 1 kΩ is high enough to be a negligible load, and low enough to charge the
capacitors Cout in less than one second.
4.8
Standby mode
When the TS4909 is in standby mode, the time required to put the output stages (Vout1,
Vout2 and Vout3) into a high impedance state with reference to ground, and the internal
circuitry in standby mode, is a few microseconds.
Figure 83. Internal equivalent circuit schematics of the TS4909 in standby mode
Vin1
Vout1
25K
1M
BYPASS
Vout3
25K
Vin2
Vout2
1M
GND
28/32
TS4909
5
Package information
Package information
In order to meet environmental requirements, STMicroelectronics offers these devices in
ECOPACK® packages. These packages have a lead-free second level interconnect. The
category of second level interconnect is marked on the package and on the inner box label,
in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics
trademark. ECOPACK specifications are available at: www.st.com.
Figure 84. TS4909 footprint recommendation
29/32
Package information
TS4909
Figure 85. DFN10 3x3 exposed pad package mechanical data
Dimensions
Ref.
Millimeters
Min.
Typ.
Max.
Min.
Typ.
Max.
0.80
0.90
1.00
31.5
35.4
39.4
A1
0.02
0.05
0.8
2.0
A2
0.70
25.6
A3
0.20
7.9
A
b
0.18
D
D2
E2
2.21
0.30
7.1
2.26
1.49
1.64
2.31
87.0
0.4
11.8
89.0
91.0
118.1
1.74
58.7
0.50
0.3
9.1
118.1
3.00
e
L
0.23
3.00
E
30/32
Mils
64.6
68.5
19.7
0.5
11.8
15.7
19.7
TS4909
6
Ordering information
Ordering information
Table 8.
Order code
Part number
TS4909IQT
7
Temperature range
Package
Packing
Marking
-40°C to +85°C
DFN10
Tape & reel
K909
Revision history
Table 9.
Document revision history
Date
Revision
Changes
1-Dec-2006
6
Release to production of the device.
2-Jan-2007
7
Correction of revision number of December revision (revision 6
instead of revision 5).
26-Sep-2007
8
Updated Table 2: Absolute maximum ratings.
31/32
TS4909
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