Features
TS4995
1.2 W fully differential audio power amplifier
with selectable standby and 6 dB fixed gain
■ Differential inputs
■ 90 dB PSRR @ 217 Hz with grounded inputs
■ Operates from V
■ 1.2 W rail-to-rail output power @ V
= 2.5 V to 5.5 V
CC
CC
=5 V,
THD+N=1%, F=1 kHz, with an 8 Ω load
■ 6 dB integrated fixed gain
■ Ultra-low consumption in standby mode
(10 nA)
■ Selectable standby mode (active low or active
high)
■ Ultra-fast startup time: 10 ms typ. at V
■ Available in 9-bump flip chip (300 mm bump
CC
=3.3 V
diameter)
■ Ultra-low pop and click
Applications
■ Mobile phones (cellular / cordless)
■ PDAs
■ Laptop / notebook computers
■ Portable audio devices
Description
The TS4995 is an audio power amplifier capable
of delivering 1.2 W of continuous RMS output
power into an 8 Ω load at 5 V. Thanks to its
differential inputs, it exhibits outstanding noise
immunity.
TS4995 - Flip chip 9
Pin connections (top view)
Gnd
Gnd
V
V
Bypass Stdby
Bypass Stdby
V
V
765
765
O-
O-
8
8
IN+
IN+
1
1
9
9
2
2
V
V
CC
CC
V
V
O+
O+
4
4
V
V
3
3
IN-
IN-
Stdby Mode
Stdby Mode
The TS4995 features an internal fixed gain at 6dB
which reduces the number of external
components on the application board.
The device is equipped with common mode
feedback circu itry allowing outputs to be always
biased at V
/2 regardless of the input common
CC
mode voltage.
The TS4995 is specifically designed for high
quality audio applications such as mobile phones
and requires few external components.
An external standby mode control reduces the
supply current to less than 10 nA. A STBY MODE
pin allows the standby pin to be active high or
low. An internal thermal shutdown protection is
also provided, making the device capable of
sustaining short-circuits.
March 2008 Rev 3 1/26
www.st.com
26
Contents TS4995
Contents
1 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 3
2 Typical application schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1 Differential configuration principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 Common mode feedback loop limitations . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.3 Low frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.4 Power dissipation and efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.5 Decoupling of the circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.6 Wake-up time t
4.7 Shutdown time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.8 Pop performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.9 Single-ended input configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
WU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2/26
TS4995 Absolute maximum ratings and operating conditions
1 Absolute maximum ratings and operating conditions
Table 1. Absolute maximum ratings (AMR)
Symbol Parameter Value Unit
(2)
(1)
(4)
(5)
(3)
6V
GND to V
CC
V
200 °C/W
200 V
1.5 kV
V
CC
V
in
T
oper
T
stg
T
R
thja
P
diss
ESD
Supply voltage
Input voltage
Operating free air temperature range -40 to + 85 °C
Storage temperature -65 to +150 °C
Maximum junction temperature 150 °C
j
Thermal resistance junction to ambient
Power dissipation Internally limited W
MM: machine model
HBM: human body model
Latch-up Latch-up immunity 200 mA
- Lead temperature (soldering, 10sec) 260 °C
1. All voltage values are measured with respect to the ground pin.
2. The magnitude of input signal must never exceed V
3. The device is protected in case of over temperature by a thermal shutdown activated at 150° C.
4. Machine model: a 200 pF cap is charged to the specified voltage, then discharged directly between two pins of the device
with no external series resistor (internal resistor < 5 Ω), done for all couples of pin combinations with other pins floating.
5. Human body model: 100 pF discharged through a 1.5 kΩ resistor between two pins of the device, done for all couples of pin
combinations with other pins floating.
Table 2. Operating conditions
+ 0.3 V / GND - 0.3 V.
CC
Symbol Parameter Value Unit
V
Supply voltage 2.5 to 5.5 V
CC
Standby mode voltage input:
V
SM
Standby Active LOW
Standby Active HIGH
=GND
V
SM
VSM=V
CC
V
Standby voltage input:
V
STBY
T
SD
R
L
R
thja
1. The minimum current consumption (I
temperature range.
Device ON (V
Device OFF (V
=GND) or Device OFF (VSM=VCC)
SM
=GND) or Device ON (VSM=VCC)
SM
Thermal shutdown temperature 150 °C
Load resistor ≥ 4 Ω
Thermal resistance junction to ambient 100 °C/W
) is guaranteed when V
STBY
1.5 ≤ V
GND ≤ V
= GND or VCC (the supply rails) for the whole
STB Y
STBY
STBY
≤ VCC
≤ 0.4
(1)
V
3/26
Typical application schematics TS4995
2 Typical application schematics
Table 3. External component descriptions
Component Functional description
C
s
C
b
C
in
Supply bypass capacitor that provides power supply filtering.
Bypass capacitor that provides half supply filtering.
Optional input capacitor that forms a high pass filter together with Rin.
= 1 / (2 x π x Rin x Cin)
(F
cl
Figure 1. Typical application
Optional
VinP1
P2
Vin+
Cin1
330nF
Cin2
330nF
3
1
8
TS4995
Vin-
Vin+
BYPASS
BIAS
VCC
2
Cs1
1uF
TS4995 FlipChip
Vcc
Vo-
7
Vo+
+
5
8 Ohms
1uF
3
STDBY
2
1
Cbypass1
VCC
4/26
4
STDBY / Operation
STBY
STDBY MODE
9
2
3
GND
6
STDBY MODE
1
TS4995 Electrical characteristics
3 Electrical characteristics
Table 4. VCC = +5V, GND = 0V, T
= 25°C (unless otherwise specified)
amb
Symbol Parameter Test conditions Min. Typ. Max. Unit
Supply current No input signal, no load 4 7 mA
I
CC
I
THD + N
PSRR
Standby current
STBY
Differential output offset
V
oo
voltage
V
Input common mode voltage 0 4.5 V
IC
Output power THD = 1% Max, F= 1kHz, RL = 8Ω 0.8 1.2 W
P
o
Total harmonic distortion +
noise
Power supply rejection ratio
IG
with inputs grounded
(1)
CMRR Common mode rejection ratio
SNR Signal-to-noise ratio
GBP Gain bandwidth product R
No input signal, V
No input signal, V
No input signal, R
Po = 850mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %
F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
V
= 200mV
ripple
F = 217Hz, RL = 8Ω, Cin = 4.7µF, Cb =1µF
= 200mV
V
ic
PP
A-weighted filter
= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100
R
L
= 8Ω 2MHz
L
= VSM = GND, RL = 8Ω
STBY
= VSM = VCC, RL = 8Ω
STBY
= 8Ω 0.110mV
L
PP
75
10 1000 nA
(2)
90 dB
60 dB
20Hz ≤ F ≤ 20kHz, RL = 8Ω
Unweighted
Output voltage noise
V
N
A-weighted
Unweighted, standby
A-weighted, standby
Z
Input impedance 15 20 25 kΩ
in
11
7
3.5
1.5
µV
- Gain mismatch 5.5 6 6.5 dB
t
Wake-up time
WU
1. Dynamic measurements - 20*log(rms(V
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
(3)
Cb =1µF 15 ms
)/rms (V
out
ripple
)). V
is the super-imposed sinus signal relative to VCC.
ripple
dB
RMS
5/26
Electrical characteristics TS4995
Table 5. VCC = +3.3V (all electrical values are guaranteed with correlation measurements at
2.6V and 5V), GND = 0V , T
= 25°C (unless otherwise specified)
amb
Symbol Parameter Test conditions Min. Typ. Max. Unit
I
Supply current No input signal, no load 3 7 mA
CC
I
THD + N
PSRR
Standby current
STBY
Differential output offset
V
oo
voltage
V
Input common mode voltage 0.4 2.3 V
IC
P
Output power THD = 1% max, F= 1kHz, RL = 8Ω 300 500 mW
o
Total harmonic distortion +
noise
Power supply rejection ratio
IG
with inputs grounded
(1)
CMRR Common mode rejection ratio
SNR Signal-to-noise ratio
GBP Gain bandwidth product R
Output voltage noise
V
N
No input signal, V
No input signal, V
No input signal, R
Po = 300mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %
F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
V
= 200mV
ripple
F = 217Hz, R
Vic = 200mV
= 8Ω, Cin = 4.7µF, Cb =1µF
L
PP
A-weighted filter
= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100
R
L
= 8Ω 2MHz
L
20Hz ≤ F ≤ 20kHz, R
Unweighted
A weighted
Unweighted, standby
A weighted, standby
= VSM = GND, RL = 8Ω
STBY
= VSM = VCC, RL = 8Ω
STBY
= 8Ω 0.110mV
L
PP
75
10 1000 nA
(2)
90 dB
60 dB
= 8Ω
L
11
7
µV
3.5
1.5
dB
RMS
Z
Input impedance 15 20 25 kΩ
in
- Gain mismatch 5.5 6 6.5 dB
Wake-up time
t
WU
1. Dynamic measurements - 20*log(rms(V
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
(3)
Cb =1µF 10 ms
)/rms (V
out
ripple
)). V
is the super-imposed sinus signal relative to VCC.
ripple
6/26
TS4995 Electrical characteristics
Table 6. VCC = +2.6V, GND = 0V, T
= 25°C (unless otherwise specified)
amb
Symbol P arameter Test condition s Min. Ty p. Max. Unit
I
Supply current No input signal, no load 3 7 mA
CC
I
STBY
THD + N
PSRR
CMRR
Standby current
Differential output offset
V
oo
voltage
V
Input common mode voltage 0.6 1.5 V
IC
P
Output power THD = 1% max, F= 1kHz, RL = 8Ω 200 300 mW
o
Total harmonic distortion +
noise
Power supply rejection ratio
IG
with inputs grounded
(1)
Common mode rejection
ratio
SNR Signal-to-noise ratio
GBP Gain bandwidth product R
Output voltage noise
V
N
No input signal, V
No input signal, V
No input signal, R
Po = 225mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω 0.5 %
F = 217Hz, R = 8Ω, Cin = 4.7μF, Cb =1µF
V
= 200mV
ripple
F = 217Hz, RL = 8Ω, Cin = 4.7μF, Cb =1µF
= 200mV
V
ic
PP
A-weighted filter
= 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz 100
R
L
= 8Ω 2MHz
L
20Hz ≤ F ≤ 20kHz, R
Unweighted
A weighted
Unweighted, standby
A weighted, standby
= VSM = GND, RL = 8Ω
STBY
= VSM = VCC, RL = 8Ω
STBY
= 8Ω 0.1 10 mV
L
PP
75
10 1000 nA
(2)
90 dB
60 dB
= 8Ω
L
11
7
3.5
1.5
µV
dB
RMS
Z
Input impedance 15 20 25 kΩ
in
- Gain mismatch 5.5 6 6.5 dB
Wake-up time
t
WU
1. Dynamic measurements - 20*log(rms(V
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
(3)
Cb =1µF 10 ms
)/rms (V
out
ripple
)). V
is the super-imposed sinus signal relative to VCC.
ripple
7/26
Electrical characteristics TS4995
Figure 2. THD+N vs. output power Figure 3. THD+N vs. output power
10
RL = 8
Ω
G = 6dB
F = 20Hz
Cb = 1μF
BW < 125kHz
1
Tamb = 25°C
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 8
Ω
G = 6dB
F = 20Hz
Cb = 0
BW < 125kHz
1
Tamb = 25°C
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
Figure 4. THD+N vs. output power Figure 5. THD+N vs. output power
10
RL = 16
G = 6dB
F = 20Hz
Cb = 1μF
BW < 125kHz
1
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 16
G = 6dB
F = 20Hz
Cb = 0
BW < 125kHz
1
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Figure 6. THD+N vs. output power Figure 7. THD+N vs. output power
10
RL = 4
Ω
G = 6dB
F = 1kHz
Cb = 1μF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 4
Ω
G = 6dB
F = 1kHz
Vcc=5V
Cb = 0
BW < 125kHz
Tamb = 25°C
Vcc=3.3V
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Vcc=2.6V
Output power (W)
8/26
TS4995 Electrical characteristics
Figure 8. THD+N vs. output power Figure 9. THD+N vs. output power
10
RL = 8
Ω
G = 6dB
F = 1kHz
Cb = 1μF
BW < 125kHz
1
Tamb = 25°C
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 8
Ω
G = 6dB
F = 1kHz
Cb = 0
BW < 125kHz
1
Tamb = 25°C
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
Figure 10. THD+N vs. output power Figure 11. THD+N vs. output power
10
RL = 16
G = 6dB
F = 1kHz
Cb = 1μF
1
BW < 125kHz
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 16
G = 6dB
F = 1kHz
Cb = 0
1
BW < 125kHz
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Figure 12. THD+N vs. output power Figure 13. THD+N vs. output power
10
RL = 4
Ω
G = 6dB
F = 20kHz
Vcc=5V
Cb = 1μF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Vcc=3.3V
Vcc=2.6V
Output power (W)
10
RL = 4
Ω
G = 6dB
F = 20kHz
Vcc=5V
Cb = 0
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Vcc=3.3V
Vcc=2.6V
Output power (W)
9/26
Electrical characteristics TS4995
Figure 14. THD+N vs. output power Figure 15. THD+N vs. output power
10
RL = 8
Ω
G = 6dB
F = 20kHz
Cb = 1μF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 8
Ω
G = 6dB
F = 20kHz
Cb = 0
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
0.1
1E-3 0.01 0.1 1
Output power (W)
Vcc=5V
Vcc=3.3V
Vcc=2.6V
Figure 16. THD+N vs. output power Figure 17. THD+N vs. output power
10
RL = 16
G = 6dB
F = 20kHz
Cb = 1μF
1
BW < 125kHz
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
10
RL = 16
G = 6dB
F = 20kHz
Cb = 0
1
BW < 125kHz
Tamb = 25°C
Ω
Vcc=5V
Vcc=3.3V
Vcc=2.6V
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
0.1
THD + N (%)
0.01
1E-3 0.01 0.1 1
Output power (W)
Figure 18. THD+N vs. frequency Figure 19. THD+N vs. frequency
THD + N (%)
0.01
10
1
0.1
RL = 4
Ω
G = 6dB
Cb = 1μF
BW < 125kHz
Vcc=5V, Po=1000mW
Tamb = 25°C
Vcc=2.6V, Po=280mW
Vcc=3.3V, Po=500mW
100 1000 10000
Frequency (Hz)
THD + N (%)
0.1
0.01
10
RL = 4
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25°C
1
Ω
Vcc=5V, Po=1000mW
Vcc=2.6V, Po=280mW
Vcc=3.3V, Po=500mW
100 1000 10000
Frequency (Hz)
10/26
TS4995 Electrical characteristics
Figure 20. THD+N vs. frequency Figure 21. THD+N vs. frequency
THD + N (%)
0.01
10
RL = 8
G = 6dB
Cb = 1μF
BW < 125kHz
Tamb = 25C
1
Vcc=5V, Po=850mW
0.1
Ω
Vcc=2.6V, Po=225mW
Vcc=3.3V, Po=300mW
100 1000 10000
Frequency (Hz)
THD + N (%)
0.01
10
RL = 8
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25C
1
Vcc=5V, Po=850mW
0.1
Ω
Vcc=2.6V, Po=225mW
Vcc=3.3V, Po=300mW
100 1000 10000
Frequency (Hz)
Figure 22. THD+N vs. frequency Figure 23. THD+N vs. frequency
10
RL = 16
G = 6dB
Cb = 1μF
BW < 125kHz
Tamb = 25C
1
Ω
Vcc=5V, Po=500mW
10
RL = 16
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25C
1
Ω
Vcc=5V, Po=500mW
THD + N (%)
0.1
0.01
Vcc=2.6V, Po=125mW
Vcc=3.3V, Po=225mW
100 1000 10000
Frequency (Hz)
Figure 24. Output power vs. power supply
voltage
10
RL = 16
Ω
G = 6dB
Cb = 1μF
BW < 125kHz
Tamb = 25C
1
Vcc=5V, Po=500mW
THD + N (%)
0.1
0.01
Vcc=2.6V, Po=125mW
Vcc=3.3V, Po=225mW
100 1000 10000
Frequency (Hz)
THD + N (%)
0.1
0.01
Vcc=2.6V, Po=125mW
Vcc=3.3V, Po=225mW
100 1000 10000
Frequency (Hz)
Figure 25. Output power vs. power supply
voltage
2,4
Cb = 1μF
2,2
F = 1kHz
BW < 125 kHz
2,0
Tamb = 25°C
1,8
1,6
1,4
1,2
1,0
0,8
0,6
0,4
0,2
Output power at 10% THD + N (W )
0,0
2,5 3,0 3,5 4,0 4,5 5,0 5,5
4Ω
8Ω
16Ω
32Ω
Vcc (V)
11/26
Electrical characteristics TS4995
0.0 0.1 0.2 0.3 0.4
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
RL=4
Ω
RL=8
Ω
Vcc=2.6V
F=1kHz
THD+N<1%
RL=16
Ω
Power Dissipation (W)
Output Power (W)
Figure 26. Output power vs. power supply
Figure 27. Power derating curves
voltage
2,0
Cb = 1μF
1,8
F = 1kHz
BW < 125 kHz
1,6
1,4
1,2
Tamb = 25°C
4
Ω
8
Ω
1,0
16
0,8
Ω
0,6
0,4
0,2
Output power at 1% THD + N (W )
0,0
2,5 3,0 3,5 4,0 4,5 5,0 5,5
32
Ω
1.2
1.0
0.8
0.6
0.4
No Heat sink
0.2
Flip-Chip Package Power Dissipation (W)
0.0
0255075100125
Ambiant Temperature (°C)
Heat sink surface ≈ 100mm
2
Vcc (V)
Figure 28. Output power vs. load resistance Figure 29. Power dissipation vs. output power
1.4
Vcc=5V
F=1kHz
1.2
THD+N<1%
1.0
0.8
0.6
0.4
Power Dissipation (W)
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
RL=16
Ω
Output Power (W)
RL=4
RL=8
Ω
Ω
Output power (W)
2000
1800
1600
1400
1200
1000
800
600
400
200
0
Vcc=5.5V
Vcc=5V
Vcc=4.5V
Vcc=4V
4 6 8101214161820222426283032
Load Resistance (Ω)
THD+N = 1%
F = 1kHz
Cb = 1μF
BW < 125kHz
Tamb = 25°C
Vcc=3.3V
Vcc=2.6V
Figure 30. Power dissipation vs. output power Figure 31. Power dissipation vs. output power
0.6
Vcc=3.3V
F=1kHz
0.5
THD+N<1%
0.4
0.3
0.2
Power Dissipation (W)
0.1
0.0
12/26
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
RL=16
Ω
Output Power (W)
RL=8
RL=4
Ω
Ω
TS4995 Electrical characteristics
Figure 32. PSSR vs. frequency Figure 33. PSSR vs. frequency
0
Vcc = 2.6V
-10
Vripple = 200mVpp
-20
RL ≥ 8
-30
G = 6dB, Cin = 4.7μF
Inputs grounded
-40
Tamb = 25°C
-50
-60
-70
PSRR (dB)
-80
-90
-100
-110
20
Ω
Cb=0
Cb=1μF, 0.47μF, 0.1μF
100 1000 10000
Frequency (Hz)
PSRR (dB)
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
0
20
Vcc = 2.6V
Vripple = 200mVpp
RL ≥ 8
Ω
G = 6dB
Inputs flo at ing
Tamb = 25°C
100 1000 10000
Cb=0
Cb=1μF, 0.47μF, 0.1μF
Frequency (Hz)
Figure 34. PSSR vs. frequency Figure 35. PSSR vs. frequency
0
Vcc = 3.3V
-10
Vripple = 200mVpp
-20
RL ≥ 8
-30
G = 6dB, Cin = 4.7μF
Inputs grounded
-40
Tamb = 25°C
-50
-60
-70
PSRR (dB)
-80
-90
-100
-110
20
Ω
Cb=0
Cb=1μF, 0.47μF, 0.1μF
100 1000 10000
Frequency (Hz)
PSRR (dB)
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
0
20
Vcc = 3.3V
Vripple = 200mVpp
RL ≥ 8
Ω
G = 6dB
Inputs flo at ing
Tamb = 25°C
100 1000 10000
Cb=0
Cb=1μF, 0.47μF, 0.1μF
Frequency (Hz)
Figure 36. PSSR vs. frequency Figure 37. PSSR vs. frequency
0
Vcc = 5V
-10
Vripple = 200mVpp
-20
RL ≥ 8
-30
G = 6dB, Cin = 4.7μF
Inputs grounded
-40
Tamb = 25°C
-50
-60
-70
PSRR (dB)
-80
-90
-100
-110
20
Ω
Cb=0
Cb=1μF, 0.47μF, 0.1μF
100 1000 10000
Frequency (Hz)
13/26
PSRR (dB)
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
0
20
Vcc = 5V
Vripple = 200mVpp
RL ≥ 8
Ω
G = 6dB
Inputs flo at ing
Tamb = 25°C
100 1000 10000
Cb=0
Frequency (Hz)
Cb=1, 0.4 7 , 0 .1μF
Electrical characteristics TS4995
Figure 38. PSSR vs. common mode input
voltage
20
Vcc = 5V
Vripple = 200mVpp
0
F = 217Hz
G = 6dB
-20
RL ≥ 8
Ω
Tamb = 25°C
PSRR (dB)
-40
-60
-80
-100
Cb=0
012345
Common Mode Input Voltage (V)
Cb=0.1μF
Cb=0.47μF
Cb=1μF
Figure 40. PSSR vs. common mode input
voltage
20
Vcc = 2.6V
Vripple = 200mVpp
0
F = 217Hz
G = 6dB
-20
RL ≥ 8
Ω
Tamb = 25°C
-40
-60
PSRR (dB)
-80
-100
0.00.51.01.52.02.5
Cb=0
Common Mode Input Voltage (V)
Cb=0.1μF
Cb=0.47μF
Cb=1μF
Figure 39. PSSR vs. common mode input
voltage
20
Vcc = 3.3V
Vripple = 200mVpp
0
F = 217Hz
G = 6dB
-20
RL ≥ 8
Ω
Tamb = 25°C
PSRR (dB)
-40
-60
-80
-100
Cb=0
0.0 0.6 1.2 1.8 2.4 3.0
Common Mode Input Voltage (V)
Cb=0.1μF
Cb=0.47μF
Cb=1μF
Figure 41. CMRR vs. frequency
0
Vcc = 5V
-10
G = 6dB
Vic = 200mVpp
-20
RL ≥ 8
-30
-40
-50
CMRR (dB)
-60
-70
-80
Ω
Cin = 470μF
Tamb = 25°C
100 1000 10000
Cb=1μF
Cb=0.47μF
Cb=0.1μF
Cb=0
Frequency (dB)
Figure 42. CMRR vs. frequency Figure 43. CMRR vs. frequency
0
Vcc = 3.3V
-10
G = 6dB
Vic = 200mVpp
-20
RL ≥ 8
-30
-40
-50
CMRR (dB)
-60
-70
-80
Ω
Cin = 470μF
Tamb = 25°C
100 1000 10000
Cb=1μF
Cb=0.47μF
Cb=0.1μF
Cb=0
Frequency (dB)
14/26
-10
-20
-30
-40
-50
CMRR (dB)
-60
-70
-80
0
Vcc = 2.6V
G = 6dB
Vic = 200mVpp
RL ≥ 8
Ω
Cin = 470μF
Tamb = 25°C
100 1000 10000
Cb=1μF
Cb=0.47μF
Cb=0.1μF
Cb=0
Frequency (dB)
TS4995 Electrical characteristics
Figure 44. CMRR vs. common mode input
voltage
20
Vic = 200mVpp
10
F = 217Hz
Cb = 1μF
0
RL ≥ 8
-10
-20
-30
-40
-50
CMRR (dB)
-60
-70
-80
-90
Ω
Tamb = 25°C
Vcc=2.6V
0.00.51.01.52.02.53.03.54.04.55.0
Common Mode Input Voltage (V)
Vcc=5V
Vcc=3.3V
Figure 46. Current consumption vs. power
supply voltage
5.0
No loads
4.5
Tamb = 25°C
4.0
3.5
3.0
2.5
2.0
1.5
1.0
Current consumption (mA)
0.5
0.0
0123456
Power Supply Voltage (V)
Figure 45. CMRR vs. common mode input
voltage
20
Vic = 200mVpp
10
F = 217Hz
Cb = 0
0
RL ≥ 8
-10
-20
-30
-40
-50
CMRR (dB)
-60
-70
-80
-90
Ω
Tamb = 25°C
Vcc=2.6V
0.00.51.01.52.02.53.03.54.04.55.0
Common Mode Input Voltage (V)
Vcc=5V
Vcc=3.3V
Figure 47. Differential DC output voltage vs.
common mode input voltage
G = 6dB
Tamb = 25°C
0.1
Vcc=2.6V
Vcc=3.3V
Vcc=5V
012345
Common Mode Input Voltage (V)
|Voo| (dB)
0.01
1E-3
1E-4
1E-5
Figure 48. Current consumption vs. standby
voltage
4.0
3.5
3.0
2.5
2.0
1.5
1.0
Current Consumption (mA)
0.5
0.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Standby mode=0V
Standby mode=5V
Standby Voltage (V)
Vcc = 5V
No load
Tamb = 25°C
Figure 49. Current consumption vs. standby
voltage
4.0
3.5
3.0
2.5
2.0
1.5
1.0
Current Consumption (mA)
0.5
0.0
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2
15/26
Standby mode=0V
Standby mode=3.3V
Standby Voltage (V)
Vcc = 3.3V
No load
Tamb = 25°C
Electrical characteristics TS4995
Figure 50. Current consumption vs. standby
Figure 51. Frequency response
voltage
4.0
3.5
3.0
2.5
2.0
1.5
1.0
Current Consumption (mA)
0.5
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6
Standby mode=2.6V
Standby Voltage (V)
Standby mode=0V
Vcc = 2.6V
No load
Tamb = 25°C
8
7
6
5
4
3
Gain (dB)
2
1
0
20
Cin=4.7μF
Cin=330nF
100 1000 10000
Frequency (Hz)
Figure 52. Frequency response Figure 53. Frequency response
8
7
6
5
4
3
Gain (dB)
2
1
0
20
Cin=4.7μF
Cin=330nF
Vcc = 3.3V
Gain = 6dB
ZL = 8Ω + 500pF
Tamb = 25°C
100 1000 10000
Frequency (Hz)
20k
8
7
6
5
4
3
Gain (dB)
2
1
0
20
Cin=4.7μF
Cin=330nF
100 1000 10000
Frequency (Hz)
Vcc = 5V
Gain = 6dB
ZL = 8Ω + 500pF
Tamb = 25°C
Vcc = 2.6V
Gain = 6dB
ZL = 8Ω + 500pF
Tamb = 25°C
20k
20k
Figure 54. SNR vs. power supply voltage with
unweighted filter
120
F = 1kHz
118
G = 6dB
Cb = 1μF
116
THD + N < 0.7%
114
Tamb = 25°C
112
110
108
106
104
Signal to Noise Ratio (dB)
102
100
2.5 3 .0 3.5 4.0 4.5 5 .0 5.5
16/26
RL=16Ω
RL=8Ω
Power Supply Voltage (V)
Figure 55. SNR vs. power supply voltage with
A-weighted filter
120
F = 1kHz
118
G = 6dB
Cb = 1μF
116
THD + N < 0.7%
114
Tamb = 25°C
112
110
108
106
104
Signal to Noise Ratio (dB)
102
100
2.5 3 .0 3.5 4.0 4.5 5 .0 5.5
RL=16Ω
Power Supply Voltage (V)
RL=8Ω
TS4995 Application information
4 Application information
4.1 Differential configuration principle
The TS4995 is a monolithic full-differential input/ output power amplifier with fixed +6 dB
gain. The TS4995 also includes a common mode feedback loop that controls the output bias
value to average it at V
output voltage swing, and therefore, to maximize the output power. Moreover, as the load is
connected differentially instead of single-ended, output power is four times higher for the
same power supply voltage.
The advantages of a full-differential amplifier are:
● Very high PSRR (power supply rejection ratio)
● High common mode noise rejection
● Virtually no pop and click without additional circuitry, giving a faster start-up time
compared to conventional single-ended input amplifiers
● Easier interfacing with differential output audio DAC
● No input coupling capacitors required due to common mode feedback loop
In theory, the filtering of the internal bias by an external bypass capacitor is not necessary.
However, to reach maximum performance in all tolerance situations, it is recommended to
keep this option.
/2 for any DC com mon mode input voltage. This allows maximum
CC
4.2 Common mode feedback loop limitations
As explained pre viously, the common mode feedback loop allo ws the output DC bias v oltage
to be averaged at V
Due to the V
limitation of the input stage (see Table 4 on page 5), the common mode
IC
/2 for any DC common mode bias input voltage.
CC
feedback loop can fulfil its role only within the defined range.
4.3 Low frequency response
The input coupling capacitors bloc k the DC part of the input signal at the amplifier inputs. Cin
and R
Note: The input impedance for the TS4995 is typically 20k
value.
From Figure 56, you can easily establish the C
form a first-order high pass filter with -3 dB cut-off frequency.
in
F
CL
1
=
CR2
××π×
value required f or a -3 dB cut- off freq uency.
in
)Hz(
inin
Ω
and there is tolerance around this
17/26
Application information TS4995
Figure 56. -3 dB lower cut-off frequency vs. input capacitance
All gain se ttin g
100
Typical Input
Impedance
10
Low -3dB Cut Off Frequency (Hz)
Maximum Input
Impedance
Tamb=25°C
Minimum Input
Impedance
0.1
Input Capacitor Cin (μF)
4.4 Power dissipation and efficiency
Assumptions:
● Load voltage and current are sinusoidal (V
● Supply voltage is a pure DC source (V
The output voltage is:
V
out
and
I
out
and
=
P
out
CC
= V
peak
V
out
------------ -
=
R
V
peak
-------------------- -
2R
out
)
L
L
and I
sinωt (V)
(A)
2
(W)
0.5 1
)
out
Therefore, the average current delivered by the supply voltage is:
Equation 1
Icc
AVG
The power delivered by the supply voltage is:
Equation 2
P
= VCC I
supply
18/26
= 2
ccAVG
V
peak
---------------- -
πR
L
(W)
(A)
TS4995 Application information
Therefore, the power dissipated by each amplifier is:
P
diss
= P
supply
- P
out
(W)
P
diss
22V
CC
----------------------
π R
L
P
–=
outPout
and the maximum value is obtained when:
∂Pdiss
-------------------- -
∂P
= 0
out
and its value is:
Equation 3
2
Vcc2
=
maxPdiss
π
)W(
2
R
L
Note: This maximum value is only dependent on the power supply voltage and load values.
The efficiency is the ratio between the output power and the power supply:
Equation 4
P
-------------------
η =
P
supply
The maximum theoretical value is reached when V
η =
πV
out
--------------------
=
peak
π
---- - = 78.5%
4
peak
4V
CC
= VCC, so:
The maximum die temperature allowable for the TS4995 is 125° C. However, in case of
overheating, a thermal shutdown set to 150° C, puts the TS4995 in standby until the
temperature of the die is reduced by about 5° C.
To calculate the maximum ambient temperature T
● The power supply voltage, V
●
The load resistor value, R
●
The package type, R
thja
Example: VCC=5 V, RL=8 Ω, R
CC
L
thja-flipchip
= 100° C/W (100 mm2 copper heatsink).
allowable, you need to know:
amb
Using the power dissipation formula given above in Equation 3, this gives a result of:
P
T
is calculated as follows:
amb
dissmax
= 633mW
Equation 5
T
125° CR
amb
Therefore, the maximum allowable value for T
T
= 125-100x0.633=61.7° C
amb
19/26
×–=
thjaPdissmax
is:
amb
Application information TS4995
4.5 Decoupling of the circuit
Two capacitors ar e ne ed e d to co rr ec tly bypass the TS4995: a power supply bypass
capacitor C
The C
and an indirect influence on pow er supply di sturbances . With a v alue for C
expect THD+N performance similar to that shown in the datasheet.
and a bias voltage bypass capacitor Cb.
S
capacitor has particular influence on the THD+N at high frequen cies (above 7 kHz)
S
of 1 µF, one can
S
In the high frequency region, if C
disturbances on the power supply rail ar e less filtered.
On the other hand, if C
is greater than 1 µF, then those disturbances on the power supply
S
rail are more filtered.
The C
capacitor has an influence on the THD+N at lower freque ncies, but also impacts
b
PSRR performance (with grounded input and in the lower frequency region) .
4.6 Wake-up time tWU
When the standby is released to put the device ON, the bypass ca pacit or Cb is not charged
immediately. Because C
properly until the C
time or t
and is specified in Table 4 on page 5, with Cb=1 µF. During the wake-up phase,
WU
the TS4995 gain is close to zero. After the wake-up time, the gain is released and set to its
nominal value.
If C
has a value different from 1 µF, then refer to the graph in Figure 57 to estab lish the
b
corresponding wake-up time.
Figure 57. Startup time vs. bypass capacitor
is directly linked to the bias of the amplifier, the bias will not work
b
voltage is correct. The time to reach this voltage is called the wake-up
b
15
is lower than 1 µF, then THD+N increases and
S
Tamb=25°C
Vcc=5V
10
5
Startup Time (ms)
Vcc=2.6V
0
0.00.40.81.21.62.0
Bypass Capacitor Cb (μF)
20/26
Vcc=3.3V
TS4995 Application information
4.7 Shutdown time
When the standby command is set, the time required to put the two output stages in high
impedance and the internal circuitry in shutdown mode is a few micr oseconds.
Note: In shutdown mode, the Bypass pin and V
switches. This allows a quick discharge of C
+, Vin- pins are shorted to ground by internal
in
and Cin.
b
4.8 Pop performance
Due to its fully differential structure, the pop performance of the TS4995 is close to perfect.
However, due to mismatching between internal resistors R
capacitors C
components, the TS4995 includes pop reduction circuitry . With this circuitry, the TS4995 is
close to zero pop for all possible common applications.
In addition, when the TS4995 is in standb y mode, due to the h igh impedance output stage in
this configuration, no pop is heard.
, some noise might remain at startup. To eliminate the effect of mismatched
in
4.9 Single-ended input configuration
It is possible to use the TS4995 in a single-ended input configuration. However, input
coupling capacitors are needed in this configuration. The schematic diagram in Figure 58
shows an example of this configuration.
, R
in
, and external input
feed
21/26
Application information TS4995
Figure 58. Typical single-ended input application
VCC
Cs1
1uF
2
TS4995
Ve
P1
Cin1
330nF
Cin2
330nF
Cbypass1
1uF
VCC
3
1
8
Vin-
Vin+
BYPASS
3
STDBY
2
1
BIAS
STBY
4
STD BY / Operatio n
Vcc
STDBY MODE
9
2
3
1
+
STDBY M OD E
TS4995 FlipChip
Vo-
Vo+
GND
6
7
5
8 Ohms
22/26
TS4995 Package information
5 Package information
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 marke d on the pa ckage and on the inner box label,
in compliance with JEDEC Standard JESD97. The maximum ratings related t o soldering
conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics
trademark. ECOPACK specifications are available at: www.st.com
.
Figure 59. 9-bump flip-chip package mechanical dra wing
1.63 mm
1.63 mm
– Die size: 1.63mm x 1.63mm ± 30µm
– Die height (including bumps): 600µm
– Bumps diameter: 315µm ±50µm
– Bump diameter before reflow: 300µm ±10µm
– Bumps height: 250µm ±40µm
0.5mm
0.5mm
1.63 mm
1.63 mm
– Die height: 350µm ±20µm
– Pitch: 500µm ±50µm
0.5mm
0.5mm
∅ 0.25mm
∅ 0.25mm
600µm600µm
– Coplanarity: 60µm max
Figure 60. Tape and reel schematics
1.5
4
4
1
1
A
A
8
8
Die size X + 70µm
Die size X + 70µm
4
4
All dimensions are in mm
All dimensions are in mm
User direction of feed
User direction of feed
A
A
Die size Y + 70µm
Die size Y + 70µm
1.5
1
1
23/26
Package information TS4995
Figure 61. Pin out (top view) Figure 62. Marking (top view)
Gnd
Gnd
E
V
V
Bypass Stdby
Bypass Stdby
V
V
765
765
O-
O-
8
8
1
1
IN+
IN+
4
4
9
9
2
2
3
3
V
V
CC
CC
Stdby Mode
Stdby Mode
– Balls are underneath
V
V
O+
O+
95
A94
V
V
IN-
IN-
A94
YWW
YWW
E
24/26
TS4995 Ordering information
6 Ordering information
Table 7. Order code
Order code
TS4995EIJT -40° C to +85° C Lead free flip chip 9 Tape & reel 95
Temperature
range
7 Revision history
Table 8. Document revision history
Date Revision Changes
1-Jun-2006 1 Final datasheet.
25-Oct-2006 2 Additional information for 4Ω load.
25-Mar-2008 3
Package Packing Marking
Modified Figure 60: Tape and reel schematics to correct die
orientation.
25/26
TS4995
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