STMICROELECTRONICS TS4995

TS4995
1.2 W fully differential audio power amplifier
with selectable standby and 6 dB fixed gain
Features
■
Differential inputs
■
90 dB PSRR @ 217 Hz with grounded inputs
■
Operates from VCC = 2.5 V to 5.5 V
■
1.2 W rail-to-rail output power @ VCC=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 VCC=3.3 V
■
Available in 9-bump flip chip (300 mm bump
diameter)
■
TS4995 - Flip chip 9
Pin connections (top view)
Gnd
VO-
7
6
5
VO+
Bypass
8
9
4
Stdby
1
2
3
VIN-
VIN+
VCC
Stdby Mode
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.
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 circuitry allowing outputs to be always
biased at VCC/2 regardless of the input common
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 tWU
4.7
Shutdown time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.8
Pop performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.9
Single-ended input configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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
(1)
VCC
Supply voltage
Vin
Input voltage (2)
6
V
GND to VCC
V
Toper
Operating free air temperature range
-40 to + 85
°C
Tstg
Storage temperature
-65 to +150
°C
Tj
Maximum junction temperature
150
°C
Rthja
Thermal resistance junction to ambient (3)
200
°C/W
Pdiss
Power dissipation
Internally limited
W
200
V
ESD
MM: machine model (4)
HBM: human body model
(5)
Latch-up Latch-up immunity
-
Lead temperature (soldering, 10sec)
1.5
kV
200
mA
260
°C
1. All voltage values are measured with respect to the ground pin.
2. The magnitude of input signal must never exceed VCC + 0.3 V / GND - 0.3 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
Symbol
Parameter
Value
Unit
VCC
Supply voltage
2.5 to 5.5
V
VSM
Standby mode voltage input:
Standby Active LOW
Standby Active HIGH
VSM=GND
VSM=VCC
V
1.5 ≤ VSTBY ≤ VCC
GND ≤ VSTBY ≤ 0.4 (1)
V
VSTBY
Standby voltage input:
Device ON (VSM=GND) or Device OFF (VSM=VCC)
Device OFF (VSM=GND) or Device ON (VSM=VCC)
TSD
Thermal shutdown temperature
150
°C
RL
Load resistor
≥4
Ω
Thermal resistance junction to ambient
100
°C/W
Rthja
1. The minimum current consumption (ISTBY) is guaranteed when VSTB Y= GND or VCC (the supply rails) for the whole
temperature range.
3/26
Typical application schematics
2
TS4995
Typical application schematics
Table 3.
External component descriptions
Component
Functional description
Cs
Supply bypass capacitor that provides power supply filtering.
Cb
Bypass capacitor that provides half supply filtering.
Cin
Optional input capacitor that forms a high pass filter together with Rin.
(Fcl = 1 / (2 x π x Rin x Cin)
Figure 1.
Typical application
VCC
Cs1
2
1uF
TS4995 FlipChip
Vcc
TS4995
Optional
Vin-
Cin1
3
Vin-
1
Vin+
8
BYP ASS
Vo-
7
Vo+
5
P1
330nF
Cin2
P2
330nF
BIAS
1uF
STDBY
4/26
STDBY MODE
1
2
6
STDBY MODE
3
STDBY / Operation
3
VCC
1
2
4
Cbypass1
GND
STBY
9
Vin+
+
8 Ohms
TS4995
Electrical characteristics
3
Electrical characteristics
Table 4.
VCC = +5V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Parameter
Test conditions
Min. Typ. Max. Unit
ICC
Supply current
No input signal, no load
4
7
mA
ISTBY
Standby current
No input signal, VSTBY = VSM = GND, RL = 8Ω
No input signal, VSTBY = VSM = VCC, RL = 8Ω
10
1000
nA
Voo
Differential output offset
voltage
No input signal, RL = 8Ω
0.1
10
mV
VIC
Input common mode voltage
4.5
V
Po
Output power
THD = 1% Max, F= 1kHz, RL = 8Ω
THD + N
Total harmonic distortion +
noise
Po = 850mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω
PSRRIG
Power supply rejection ratio
with inputs grounded(1)
F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
Vripple = 200mVPP
CMRR Common mode rejection ratio
0
0.8
75(2)
F = 217Hz, RL = 8Ω, Cin = 4.7µF, Cb =1µF
Vic = 200mVPP
1.2
W
0.5
%
90
dB
60
dB
SNR
Signal-to-noise ratio
A-weighted filter
RL = 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz
GBP
Gain bandwidth product
RL = 8Ω
VN
Output voltage noise
20Hz ≤ F ≤ 20kHz, RL = 8Ω
Unweighted
A-weighted
Unweighted, standby
A-weighted, standby
Zin
Input impedance
15
20
25
kΩ
-
Gain mismatch
5.5
6
6.5
dB
tWU
Wake-up time(3)
Cb =1µF
dB
100
2
MHz
11
7
3.5
1.5
µVRMS
15
ms
1. Dynamic measurements - 20*log(rms(Vout)/rms (Vripple)). Vripple is the super-imposed sinus signal relative to VCC.
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
5/26
Electrical characteristics
Table 5.
Symbol
TS4995
VCC = +3.3V (all electrical values are guaranteed with correlation measurements at
2.6V and 5V), GND = 0V, Tamb = 25°C (unless otherwise specified)
Parameter
Test conditions
Min. Typ. Max. Unit
ICC
Supply current
No input signal, no load
3
7
mA
ISTBY
Standby current
No input signal, VSTBY = VSM = GND, RL = 8Ω
No input signal, VSTBY = VSM = VCC, RL = 8Ω
10
1000
nA
Voo
Differential output offset
voltage
No input signal, RL = 8Ω
0.1
10
mV
VIC
Input common mode voltage
2.3
V
Po
Output power
THD = 1% max, F= 1kHz, RL = 8Ω
THD + N
Total harmonic distortion +
noise
Po = 300mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω
PSRRIG
Power supply rejection ratio
with inputs grounded(1)
F = 217Hz, R = 8Ω, Cin = 4.7µF, Cb =1µF
Vripple = 200mVPP
CMRR Common mode rejection ratio
0.4
300
75(2)
F = 217Hz, RL = 8Ω, Cin = 4.7µF, Cb =1µF
Vic = 200mVPP
500
mW
0.5
%
90
dB
60
dB
SNR
Signal-to-noise ratio
A-weighted filter
RL = 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz
GBP
Gain bandwidth product
RL = 8Ω
VN
Output voltage noise
20Hz ≤ F ≤ 20kHz, RL = 8Ω
Unweighted
A weighted
Unweighted, standby
A weighted, standby
Zin
Input impedance
15
20
25
kΩ
-
Gain mismatch
5.5
6
6.5
dB
tWU
Wake-up time(3)
Cb =1µF
dB
100
2
MHz
11
7
3.5
1.5
µVRMS
10
1. Dynamic measurements - 20*log(rms(Vout)/rms (Vripple)). Vripple is the super-imposed sinus signal relative to VCC.
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
6/26
ms
TS4995
Table 6.
Symbol
Electrical characteristics
VCC = +2.6V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Parameter
Test conditions
Min.
Typ. Max.
Unit
ICC
Supply current
No input signal, no load
3
7
mA
ISTBY
Standby current
No input signal, VSTBY = VSM = GND, RL = 8Ω
No input signal, VSTBY = VSM = VCC, RL = 8Ω
10
1000
nA
Voo
Differential output offset
voltage
No input signal, RL = 8Ω
0.1
10
mV
VIC
Input common mode voltage
1.5
V
Po
Output power
THD = 1% max, F= 1kHz, RL = 8Ω
THD + N
Total harmonic distortion +
noise
Po = 225mW rms, 20Hz ≤ F ≤ 20kHz, RL = 8Ω
PSRRIG
Power supply rejection ratio F = 217Hz, R = 8Ω, Cin = 4.7μF, Cb =1µF
with inputs grounded(1)
Vripple = 200mVPP
0.6
200
75(2)
300
mW
0.5
%
90
dB
60
dB
Common mode rejection
ratio
F = 217Hz, RL = 8Ω, Cin = 4.7μF, Cb =1µF
Vic = 200mVPP
SNR
Signal-to-noise ratio
A-weighted filter
RL = 8Ω, THD +N < 0.7%, 20Hz ≤ F ≤ 20kHz
GBP
Gain bandwidth product
RL = 8Ω
VN
Output voltage noise
20Hz ≤F ≤20kHz, RL = 8Ω
Unweighted
A weighted
Unweighted, standby
A weighted, standby
Zin
Input impedance
15
20
25
kΩ
-
Gain mismatch
5.5
6
6.5
dB
tWU
Wake-up time(3)
CMRR
Cb =1µF
dB
100
2
MHz
11
7
3.5
1.5
µVRMS
10
ms
1. Dynamic measurements - 20*log(rms(Vout)/rms (Vripple)). Vripple is the super-imposed sinus signal relative to VCC.
2. Guaranteed by design and evaluation.
3. Transition time from standby mode to fully operational amplifier.
7/26
Electrical characteristics
Figure 2.
TS4995
THD+N vs. output power
Figure 3.
10
10
RL = 8 Ω
G = 6dB
F = 20Hz
Cb = 1 μ F
1 BW < 125kHz
Tamb = 25 ° C
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
RL = 8 Ω
G = 6dB
F = 20Hz
Cb = 0
1 BW < 125kHz
Tamb = 25 ° C
Vcc=5V
THD + N (%)
THD + N (%)
THD+N vs. output power
0.01
0.1
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
1
Vcc=5V
0.01
Output power (W)
Figure 4.
THD+N vs. output power
Figure 5.
10
1
THD+N vs. output power
10
RL = 16 Ω
G = 6dB
F = 20Hz
Cb = 1 μ F
1 BW < 125kHz
Tamb = 25 ° C
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
RL = 16 Ω
G = 6dB
F = 20Hz
Cb = 0
1 BW < 125kHz
Tamb = 25 ° C
Vcc=5V
THD + N (%)
THD + N (%)
0.1
Output power (W)
0.01
0.1
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
1
Vcc=5V
0.01
Output power (W)
Figure 6.
0.1
1
Output power (W)
THD+N vs. output power
Figure 7.
THD+N vs. output power
10
RL = 4 Ω
G = 6dB
F = 1kHz
Cb = 0
BW < 125kHz
Tamb = 25 ° C
RL = 4 Ω
G = 6dB
F = 1kHz
Cb = 1 μ F
BW < 125kHz
Tamb = 25 ° C
Vcc=5V
Vcc=3.3V
THD + N (%)
THD + N (%)
10
1
Vcc=2.6V
0.1
1E-3
0.01
0.1
Output power (W)
1
Vcc=5V
Vcc=3.3V
1
Vcc=2.6V
0.1
1E-3
0.01
0.1
Output power (W)
8/26
1
TS4995
Electrical characteristics
Figure 8.
THD+N vs. output power
Figure 9.
10
RL = 8 Ω
G = 6dB
F = 1kHz
Cb = 1 μ F
1 BW < 125kHz
Tamb = 25 ° C
Vcc=5V
Vcc=3.3V
THD + N (%)
THD + N (%)
10
THD+N vs. output power
Vcc=2.6V
0.1
0.01
1E-3
0.01
0.1
RL = 8 Ω
G = 6dB
F = 1kHz
Cb = 0
1 BW < 125kHz
Tamb = 25 ° C
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
1
Vcc=5V
0.01
Output power (W)
Figure 10. THD+N vs. output power
10
RL = 16 Ω
G = 6dB
F = 1kHz
Cb = 1 μ F
1 BW < 125kHz
Tamb = 25 ° C
Vcc=5V
Vcc=3.3V
THD + N (%)
THD + N (%)
1
Figure 11. THD+N vs. output power
10
Vcc=2.6V
0.1
0.01
1E-3
0.01
0.1
RL = 16 Ω
G = 6dB
F = 1kHz
Cb = 0
1 BW < 125kHz
Tamb = 25 ° C
Vcc=3.3V
Vcc=2.6V
0.1
0.01
1E-3
1
Vcc=5V
0.01
Output power (W)
0.1
1
Output power (W)
Figure 12. THD+N vs. output power
Figure 13. THD+N vs. output power
10
10
RL = 4 Ω
G = 6dB
F = 20kHz
Cb = 1 μ F
BW < 125kHz
Tamb = 25 ° C
Vcc=3.3V
1
0.1
1E-3
RL = 4 Ω
G = 6dB
F = 20kHz
Cb = 0
BW < 125kHz
Tamb = 25 ° C
Vcc=5V
THD + N (%)
THD + N (%)
0.1
Output power (W)
Vcc=2.6V
0.01
0.1
Output power (W)
1
Vcc=5V
Vcc=3.3V
1
0.1
1E-3
Vcc=2.6V
0.01
0.1
1
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 = 1 μ F
BW < 125kHz
Tamb = 25 ° C
1
RL = 8 Ω
G = 6dB
F = 20kHz
Cb = 0
BW < 125kHz
Tamb = 25 ° C
Vcc=5V
Vcc=3.3V
THD + N (%)
THD + N (%)
10
Vcc=2.6V
0.1
1
Vcc=5V
Vcc=3.3V
Vcc=2.6V
0.1
1E-3
0.01
0.1
1
1E-3
0.01
Output power (W)
Figure 16. THD+N vs. output power
Vcc=5V
Vcc=3.3V
THD + N (%)
THD + N (%)
10
RL = 16 Ω
G = 6dB
F = 20kHz
Cb = 1 μ F
1 BW < 125kHz
Tamb = 25 ° C
Vcc=2.6V
0.1
0.01
1E-3
0.01
0.1
RL = 16 Ω
G = 6dB
F = 20kHz
Cb = 0
1 BW < 125kHz
Tamb = 25 ° C
0.01
1
Figure 19. THD+N vs. frequency
10
10
RL = 4 Ω
G = 6dB
Cb = 1 μ F
BW < 125kHz
Tamb = 25 ° C
Vcc=5V, Po=1000mW
1
Vcc=2.6V, Po=280mW
0.1
THD + N (%)
THD + N (%)
0.1
Output power (W)
Figure 18. THD+N vs. frequency
Vcc=3.3V, Po=500mW
100
1000
Frequency (Hz)
10/26
Vcc=3.3V
0.1
0.01
1E-3
1
Vcc=5V
Vcc=2.6V
Output power (W)
0.01
1
Figure 17. THD+N vs. output power
10
1
0.1
Output power (W)
10000
RL = 4 Ω
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25 ° C
Vcc=2.6V, Po=280mW
0.1
0.01
Vcc=5V, Po=1000mW
Vcc=3.3V, Po=500mW
100
1000
Frequency (Hz)
10000
TS4995
Electrical characteristics
Figure 20. THD+N vs. frequency
Figure 21. THD+N vs. frequency
10
Vcc=2.6V, Po=225mW
1
THD + N (%)
THD + N (%)
1
10
RL = 8 Ω
G = 6dB
Cb = 1 μ F
BW < 125kHz
Tamb = 25C
Vcc=5V, Po=850mW
0.1
100
1000
Vcc=2.6V, Po=225mW
Vcc=5V, Po=850mW
0.1
Vcc=3.3V, Po=300mW
0.01
RL = 8 Ω
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25C
Vcc=3.3V, Po=300mW
0.01
10000
100
1000
Frequency (Hz)
Figure 22. THD+N vs. frequency
Figure 23. THD+N vs. frequency
10
10
RL = 16 Ω
G = 6dB
Cb = 1 μ F
BW < 125kHz
Tamb = 25C
1
Vcc=5V, Po=500mW
THD + N (%)
THD + N (%)
1
Vcc=2.6V, Po=125mW
0.1
100
1000
RL = 16 Ω
G = 6dB
Cb = 0
BW < 125kHz
Tamb = 25C
Vcc=5V, Po=500mW
Vcc=2.6V, Po=125mW
0.1
Vcc=3.3V, Po=225mW
0.01
Vcc=3.3V, Po=225mW
0.01
10000
100
1000
Frequency (Hz)
Figure 25. Output power vs. power supply
voltage
10
Output power at 10% THD + N (W)
THD + N (%)
RL = 16 Ω
G = 6dB
Cb = 1 μ F
BW < 125kHz
Tamb = 25C
Vcc=5V, Po=500mW
Vcc=2.6V, Po=125mW
0.1
Vcc=3.3V, Po=225mW
0.01
100
1000
Frequency (Hz)
10000
Frequency (Hz)
Figure 24. Output power vs. power supply
voltage
1
10000
Frequency (Hz)
10000
2,4 Cb = 1μF
2,2 F = 1kHz
2,0 BW < 125 kHz
1,8 Tamb = 25°C
4Ω
1,6
1,4
1,2
8Ω
1,0
0,8
16Ω
0,6
0,4
32Ω
0,2
0,0
2,5
3,0
3,5
4,0
4,5
5,0
5,5
Vcc (V)
11/26
Electrical characteristics
TS4995
Figure 26. Output power vs. power supply
voltage
Figure 27. Power derating curves
Output power at 1% THD + N (W)
Cb = 1μF
1,8 F = 1kHz
1,6 BW < 125 kHz
Tamb = 25°C
1,4
Flip-Chip Package Power Dissipation (W)
2,0
4Ω
8Ω
1,2
1,0
16Ω
0,8
0,6
0,4
0,2
32Ω
0,0
2,5
3,0
3,5
4,0
4,5
5,0
5,5
1.2
1.0
Heat sink surface ≈ 100mm
2
0.8
0.6
0.4
No Heat sink
0.2
0.0
0
25
50
75
100
125
Ambiant Temperature ( ° C)
Vcc (V)
Figure 28. Output power vs. load resistance
Figure 29. Power dissipation vs. output power
1.4
1800
Vcc=5V
1600
Output power (W)
THD+N = 1%
F = 1kHz
Cb = 1μ F
BW < 125kHz
Tamb = 25°C
Vcc=5.5V
Vcc=4.5V
1400
Vcc=4V
1200
Vcc=3.3V
1000
Vcc=2.6V
800
600
Power Dissipation (W)
2000
Vcc=5V
1.2 F=1kHz
THD+N<1%
RL=4Ω
1.0
0.8
0.6
RL=8Ω
0.4
400
0.2
200
RL=16Ω
0
4
6
8
0.0
0.0
10 12 14 16 18 20 22 24 26 28 30 32
0.2
0.4
0.6
Load Resistance (Ω )
0.8
1.0
1.2
Output Power (W)
1.4
1.6
0.6
0.40
Vcc=3.3V
F=1kHz
0.5 THD+N<1%
0.35
RL=4Ω
Power Dissipation (W)
Power Dissipation (W)
Figure 30. Power dissipation vs. output power Figure 31. Power dissipation vs. output power
0.4
0.3
0.2
RL=8Ω
0.1
0.1
0.2
0.3
0.4
0.5
Output Power (W)
12/26
0.6
0.7
RL=4Ω
0.30
0.25
0.20
0.15
RL=8Ω
0.10
0.05
RL=16Ω
0.0
0.0
Vcc=2.6V
F=1kHz
THD+N<1%
0.00
0.0
RL=16Ω
0.1
0.2
Output Power (W)
0.3
0.4
TS4995
Electrical characteristics
Figure 32. PSSR vs. frequency
Figure 33. PSSR vs. frequency
0
-20
-30
PSRR (dB)
-40
-50
0
Vcc = 2.6V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB, Cin = 4.7 μ F
Inputs grounded
Tamb = 25 ° C
-10
-20
-30
-40
Cb=0
PSRR (dB)
-10
-60
-70
Cb=1 μ F, 0.47 μ F, 0.1 μ F
-80
-50
Vcc = 2.6V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB
Inputs floating
Tamb = 25 ° C
Cb=0
-60
-70
-80
-90
-90
-100
-100
-110
20
-110
20
100
1000
10000
Cb=1 μ F, 0.47 μ F, 0.1 μ F
100
1000
10000
Frequency (Hz)
Frequency (Hz)
Figure 34. PSSR vs. frequency
Figure 35. PSSR vs. frequency
0
-20
-30
PSRR (dB)
-40
-50
0
Vcc = 3.3V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB, Cin = 4.7 μ F
Inputs grounded
Tamb = 25 ° C
-10
-20
-30
-40
Cb=0
PSRR (dB)
-10
-60
-70
Cb=1 μ F, 0.47 μ F, 0.1 μ F
-80
-50
Cb=0
-60
-70
-80
-90
-90
-100
-100
-110
20
Vcc = 3.3V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB
Inputs floating
Tamb = 25 ° C
100
1000
-110
20
10000
Cb=1 μ F, 0.47 μ F, 0.1 μ F
100
1000
10000
Frequency (Hz)
Frequency (Hz)
Figure 36. PSSR vs. frequency
Figure 37. PSSR vs. frequency
0
-20
-30
PSRR (dB)
-40
-50
0
Vcc = 5V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB, Cin = 4.7 μ F
Inputs grounded
Tamb = 25 ° C
-10
-20
-30
-40
Cb=0
PSRR (dB)
-10
-60
-70
Cb=1 μ F, 0.47 μ F, 0.1 μ F
-80
-50
Cb=0
-60
-70
-80
-90
-90
-100
-100
-110
20
Vcc = 5V
Vripple = 200mVpp
RL ≥ 8 Ω
G = 6dB
Inputs floating
Tamb = 25 ° C
100
1000
Frequency (Hz)
10000
-110
20
Cb=1, 0.47, 0.1 μ F
100
1000
10000
Frequency (Hz)
13/26
Electrical characteristics
TS4995
Figure 38. PSSR vs. common mode input
voltage
Figure 39. PSSR vs. common mode input
voltage
20
-40
Cb=0
20
Vcc = 3.3V
Vripple = 200mVpp
0 F = 217Hz
G = 6dB
-20 RL ≥ 8 Ω
Tamb = 25°C
Cb=0.1 μ F
Cb=0.47 μ F
Cb=1 μ F
PSRR (dB)
PSRR (dB)
Vcc = 5V
Vripple = 200mVpp
0 F = 217Hz
G = 6dB
-20 RL ≥ 8 Ω
Tamb = 25°C
-60
Cb=0
-60
-80
-80
-100
-100
0
1
2
3
4
5
0.0
Common Mode Input Voltage (V)
1.2
-10
CMRR (dB)
-20
-40
Cb=0.1 μ F
Cb=0.47 μ F
Cb=1 μ F
Cb=0
-60
-30
Vcc = 5V
G = 6dB
Vic = 200mVpp
RL ≥ 8 Ω
Cin = 470 μ F
Tamb = 25 ° C
-40
0.0
-50
0.5
1.0
1.5
2.0
-80
2.5
100
Common Mode Input Voltage (V)
10000
Figure 43. CMRR vs. frequency
0
0
Vcc = 3.3V
G = 6dB
Vic = 200mVpp
RL ≥ 8 Ω
Cin = 470 μ F
Tamb = 25 ° C
-40
-10
-20
Cb=1 μ F
Cb=0.47 μ F
Cb=0.1 μ F
Cb=0
CMRR (dB)
CMRR (dB)
1000
Frequency (dB)
Figure 42. CMRR vs. frequency
-50
-30
-60
-70
1000
10000
Cb=1 μ F
Cb=0.47 μ F
Cb=0.1 μ F
Cb=0
-50
-70
100
Vcc = 2.6V
G = 6dB
Vic = 200mVpp
RL ≥ 8 Ω
Cin = 470 μ F
Tamb = 25 ° C
-40
-60
Frequency (dB)
14/26
Cb=1 μ F
Cb=0.47 μ F
Cb=0.1 μ F
Cb=0
-70
-100
-80
3.0
-60
-80
-30
2.4
0
Vcc = 2.6V
Vripple = 200mVpp
0 F = 217Hz
G = 6dB
-20 RL ≥ 8 Ω
Tamb = 25°C
-20
1.8
Figure 41. CMRR vs. frequency
20
PSRR (dB)
0.6
Common Mode Input Voltage (V)
Figure 40. PSSR vs. common mode input
voltage
-10
Cb=0.1 μ F
Cb=0.47 μ F
Cb=1 μ F
-40
-80
100
1000
Frequency (dB)
10000
TS4995
Electrical characteristics
Figure 44. CMRR vs. common mode input
voltage
Figure 45. CMRR vs. common mode input
voltage
20
20
-30
Vic = 200mVpp
10 F = 217Hz
0 Cb = 0
RL ≥ 8 Ω
-10
Tamb = 25°C
-20
CMRR (dB)
CMRR (dB)
Vic = 200mVpp
10 F = 217Hz
0 Cb = 1 μ F
RL ≥ 8 Ω
-10
Tamb = 25°C
-20
Vcc=5V
Vcc=2.6V
-40
-50
-60
-30
-50
-60
-70
-70
Vcc=3.3V
-80
Vcc=3.3V
-80
-90
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
-90
0.0
5.0
0.5
1.0
Common Mode Input Voltage (V)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Common Mode Input Voltage (V)
Figure 46. Current consumption vs. power
supply voltage
Figure 47. Differential DC output voltage vs.
common mode input voltage
5.0
No loads
4.5 Tamb = 25 ° C
G = 6dB
Tamb = 25 ° C
0.1
4.0
Vcc=2.6V
3.5
0.01
3.0
|Voo| (dB)
Current consumption (mA)
Vcc=5V
Vcc=2.6V
-40
2.5
2.0
Vcc=3.3V
1E-3
Vcc=5V
1.5
1E-4
1.0
0.5
0.0
1E-5
0
1
2
3
4
5
6
0
1
Power Supply Voltage (V)
Figure 48. Current consumption vs. standby
voltage
4
5
4.0
3.5
Standby mode=0V
3.0
2.5
Standby mode=5V
2.0
1.5
1.0
Vcc = 5V
No load
Tamb = 25 ° C
0.5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Standby Voltage (V)
4.0
4.5
5.0
Current Consumption (mA)
3.5
Current Consumption (mA)
3
Figure 49. Current consumption vs. standby
voltage
4.0
0.0
0.0
2
Common Mode Input Voltage (V)
3.0
Standby mode=0V
2.5
Standby mode=3.3V
2.0
1.5
1.0
Vcc = 3.3V
No load
Tamb = 25 ° C
0.5
0.0
0.0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
Standby Voltage (V)
15/26
Electrical characteristics
TS4995
Figure 51. Frequency response
4.0
8
3.5
7
3.0
Cin=4.7 μ F
6
Standby mode=0V
2.5
2.0
5
Gain (dB)
Current Consumption (mA)
Figure 50. Current consumption vs. standby
voltage
Standby mode=2.6V
1.5
1.0
4
Cin=330nF
3
2
Vcc = 2.6V
No load
Tamb = 25 ° C
0.5
Vcc = 5V
Gain = 6dB
ZL = 8 Ω + 500pF
Tamb = 25 ° C
1
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
0
20
100
Frequency (Hz)
Figure 52. Frequency response
Figure 53. Frequency response
8
8
Cin=4.7 μ F
6
6
5
5
4
Cin=330nF
3
2
1
100
Cin=330nF
3
Vcc = 2.6V
Gain = 6dB
ZL = 8 Ω + 500pF
Tamb = 25 ° C
1
0
10000 20k
1000
4
2
Vcc = 3.3V
Gain = 6dB
ZL = 8 Ω + 500pF
Tamb = 25 ° C
20
Cin=4.7 μ F
7
Gain (dB)
Gain (dB)
7
0
10000 20k
1000
Standby Voltage (V)
20
100
10000 20k
1000
Frequency (Hz)
Frequency (Hz)
Figure 54. SNR vs. power supply voltage with Figure 55. SNR vs. power supply voltage with
unweighted filter
A-weighted filter
Signal to Noise Ratio (dB)
118
116
114
120
F = 1kHz
G = 6dB
Cb = 1 μ F
THD + N < 0.7%
Tamb = 25°C
118
Signal to Noise Ratio (dB)
120
RL=16 Ω
112
110
108
RL=8 Ω
106
104
102
100
2.5
114
112
RL=8 Ω
110
108
RL=16 Ω
106
104
102
3.0
3.5
4.0
4.5
Power Supply Voltage (V)
16/26
116
F = 1kHz
G = 6dB
Cb = 1 μ F
THD + N < 0.7%
Tamb = 25°C
5.0
5.5
100
2.5
3.0
3.5
4.0
4.5
Power Supply Voltage (V)
5.0
5.5
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 VCC/2 for any DC common mode input voltage. This allows maximum
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.
4.2
Common mode feedback loop limitations
As explained previously, the common mode feedback loop allows the output DC bias voltage
to be averaged at VCC/2 for any DC common mode bias input voltage.
Due to the VIC limitation of the input stage (see Table 4 on page 5), the common mode
feedback loop can fulfil its role only within the defined range.
4.3
Low frequency response
The input coupling capacitors block the DC part of the input signal at the amplifier inputs. Cin
and Rin form a first-order high pass filter with -3 dB cut-off frequency.
FCL =
Note:
1
2 × π × Rin × Cin
(Hz)
The input impedance for the TS4995 is typically 20kΩ and there is tolerance around this
value.
From Figure 56, you can easily establish the Cin value required for a -3 dB cut-off frequency.
17/26
Application information
TS4995
Figure 56. -3 dB lower cut-off frequency vs. input capacitance
Low -3dB Cut Off Frequency (Hz)
All gain setting
Tamb=25 ° C
100
Minimum Input
Impedance
Typical Input
Impedance
10
Maximum Input
Impedance
0.1
0.5
Input Capacitor Cin (μ F)
4.4
Power dissipation and efficiency
Assumptions:
●
Load voltage and current are sinusoidal (Vout and Iout)
●
Supply voltage is a pure DC source (VCC)
The output voltage is:
V out = V peak sinωt (V)
and
V out
I out = ------------- (A)
RL
and
V peak 2
P out = --------------------- (W)
2R L
Therefore, the average current delivered by the supply voltage is:
Equation 1
V peak
Icc AVG = 2 ----------------- (A)
πR L
The power delivered by the supply voltage is:
Equation 2
Psupply = VCC IccAVG (W)
18/26
1
TS4995
Application information
Therefore, the power dissipated by each amplifier is:
Pdiss = Psupply - Pout (W)
2 2V CC
P diss = ---------------------- P out – P out
π RL
and the maximum value is obtained when:
∂Pdiss
--------------------- = 0
∂P out
and its value is:
Equation 3
Pdiss max =
Note:
2 Vcc 2
π2RL
(W)
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 out
πV peak
η = ------------------- = -------------------P supply
4V CC
The maximum theoretical value is reached when Vpeak = VCC, so:
π
η = ---- = 78.5%
4
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 Tamb allowable, you need to know:
●
The power supply voltage, VCC
●
The load resistor value, RL
●
The package type, Rthja
Example: VCC=5 V, RL=8 Ω, Rthja-flipchip= 100° C/W (100 mm2 copper heatsink).
Using the power dissipation formula given above in Equation 3, this gives a result of:
Pdissmax = 633mW
Tamb is calculated as follows:
Equation 5
T amb = 125° C – R thja × P dissmax
Therefore, the maximum allowable value for Tamb is:
Tamb = 125-100x0.633=61.7° C
19/26
Application information
4.5
TS4995
Decoupling of the circuit
Two capacitors are needed to correctly bypass the TS4995: a power supply bypass
capacitor CS and a bias voltage bypass capacitor Cb.
The CS capacitor has particular influence on the THD+N at high frequencies (above 7 kHz)
and an indirect influence on power supply disturbances. With a value for CS of 1 µF, one can
expect THD+N performance similar to that shown in the datasheet.
In the high frequency region, if CS is lower than 1 µF, then THD+N increases and
disturbances on the power supply rail are less filtered.
On the other hand, if CS is greater than 1 µF, then those disturbances on the power supply
rail are more filtered.
The Cb capacitor has an influence on the THD+N at lower frequencies, but also impacts
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 capacitor Cb is not charged
immediately. Because 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 is called the wake-up
time or tWU and is specified in Table 4 on page 5, with Cb=1 µF. During the wake-up phase,
the TS4995 gain is close to zero. After the wake-up time, the gain is released and set to its
nominal value.
If Cb has a value different from 1 µF, then refer to the graph in Figure 57 to establish the
corresponding wake-up time.
Figure 57. Startup time vs. bypass capacitor
15
Tamb=25 ° C
Startup Time (ms)
Vcc=5V
10
5
Vcc=3.3V
Vcc=2.6V
0
0.0
20/26
0.4
0.8
1.2
1.6
Bypass Capacitor Cb (μ F)
2.0
TS4995
4.7
Application information
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 microseconds.
Note:
In shutdown mode, the Bypass pin and Vin+, Vin- pins are shorted to ground by internal
switches. This allows a quick discharge of Cb and Cin.
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 Rin, Rfeed, and external input
capacitors Cin, some noise might remain at startup. To eliminate the effect of mismatched
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 standby mode, due to the high impedance output stage in
this configuration, no pop is heard.
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.
21/26
Application information
TS4995
Figure 58. Typical single-ended input application
VCC
Cs1
2
1uF
Ve
P1
TS4995 FlipChip
Vcc
TS4995
Cin1
3
Vin-
1
Vin+
8
BYP ASS
7
Vo+
5
330nF
Cin2
+
330nF
BIAS
1uF
STDBY MODE
1
2
9
3
4
STDBY / Operation
2
1
3
VCC
6
STDBY MODE
STDBY
GND
STBY
Cbypass1
22/26
Vo-
8 Ohms
TS4995
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 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 59. 9-bump flip-chip package mechanical drawing
1.63 mm
0.5mm
0.5mm
∅ 0.25mm
–
–
–
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
Die height: 350µm ±20µm
Pitch: 500µm ±50µm
Coplanarity: 60µm max
600µm
Figure 60. Tape and reel schematics
1.5
4
1
1
A
A
Die size Y + 70µm
5
Package information
8
Die size X + 70µm
4
All dimensions are in mm
User direction of feed
23/26
Package information
TS4995
Figure 61. Pin out (top view)
Figure 62. Marking (top view)
Gnd
VO-
7
6
5
VO+
Bypass
8
9
4
Stdby
3
VIN-
E
95
VIN+
1
2
A94
YWW
VCC
– Balls are underneath
24/26
Stdby Mode
TS4995
6
Ordering information
Ordering information
Table 7.
Order code
Order code
TS4995EIJT
7
Temperature
range
Package
Packing
Marking
-40° C to +85° C
Lead free flip chip 9
Tape & reel
95
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
Modified Figure 60: Tape and reel schematics to correct die
orientation.
25/26
TS4995
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26/26