ST TS4995 User Manual
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
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