1W Differential Input/Output Audio Power Amplifier
with Selectable Standby
■Differential inputs
■Near zero pop & click
■100dB PSRR @ 217Hz with grounded inputs
■Operating from V
= 2.5V to 5.5V
CC
■1W RAIL to RAIL output power @ Vcc=5V,
THD=1%, F=1kHz, with 8
Ω load
■90dB CMRR @ 217Hz
■Ultra-low consumption in standby mode (10nA)
■Selectable standby mode (active low or
active high
■Ultra fast startup time: 15ms typ.
■Available in DFN10 3x3, 0.5mm pitch &
MiniSO8
■All lead-free packages
Description
The TS4994 is an audio power amplifier capable
of delivering 1W of continuous RMS output power
into an 8
inputs, it exhibits outstanding noise immunity.
An external standby mode control reduces the
supply current to less than 10nA. A STBY MODE
pin allows the standby pin to be active HIGH or
LOW (except in the MiniSO8 version). An internal
thermal shutdown protection is also provided,
making the device capable of sustaining shortcircuits.
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.
Ω load @ 5V. Thanks to its differential
Pin Connections (top view)
TS4994IQT - DFN10
STBY
STBY
STBY MODE
STBY MODE
BYPASS
BYPASS
1
1
1
2
2
2
V
V
IN -
IN -
3
3
3
V
V
4
4
4
IN +
IN +
5
5
5
10
10
10
V
V
V
V
9
9
9
N/C
N/C
8
8
8
GND
GND
7
7
7
6
6
6
V
V
TS4994IST - MiniSO8
STBY
STBY
V
V
IN-
IN-
V
V
IN+
IN+
BYPASS
BYPASS
1
1
2
2
3
3
4
4
V
V
8
8
Vcc
Vcc
7
7
GND
GND
6
6
V
V
5
5
Applications
■Mobile phones (cellular / cordless)
■Laptop / notebook computers
■PDAs
■Portable audio devices
■
■
O+
O+
DD
DD
O-
O-
O+
O+
O-
O-
The TS4994 has been designed for high quality
audio applications such as mobile phones and
requires few external components.
Order Codes
Part NumberTemperature RangePackagePackagingMarking
TS4994IQT-40°C to +85°CDFN10Tape & ReelK994
TS4994IST-40°C to +85°CMiniSO8Tape & ReelK994
April 2005Revision 41/31
TS4994Application Component Information
1Application Component Information
ComponentsFunctional Description
C
S
C
B
R
FEED
R
IN
C
IN
Figure 1. Typical Application DFN10 Version
Supply Bypass capacitor which provides power supply filtering.
Bypass capacitor which provides half supply filtering.
Feedback resistor which sets the closed loop gain in conjunction with RIN
= Closed Loop Gain= R
A
V
FEED/RIN
Inverting input resistor which sets the closed loop gain in conjunction with R
.
.
FEED
Optional input capacitor making a high pass filter together with RIN. (fcl = 1 / (2 x Pi x RIN x CIN)
VCC
+
Cs
Bias
GND
Rfeed2
20k
1u
Vo+
10
Vo-
6
8 Ohms
Diff. input -
GND
Diff. Input +
Cin1
220nF
Cin2
220nF
Optional
Rfeed1
20k
Rin1
+
20k
Rin2
+
20k
+
Cb
1u
GND
Vin-
2
Vin+
4
Bypass
5
ModeStdbyTS4994IQ
9
VCC
-
+
Standby
GND
1
73
GND
GNDGNDVCCVCC
Figure 2. Typical Application Mini-SO8 Version
Rfeed1
20k
Diff. input -
Cin1
Rin1
GND
Diff. Input +
220nF
Cin2
220nF
Optional
+
20k
Rin2
+
20k
+
GND
Vin-
2
Vin+
3
Bypass
4
Cb
1u
GNDVCC
Stdby
1
VCC
7
VCC
-
+
Bias
Standby
GND
6
GND
+
GND
Rfeed2
20k
Cs
1u
Vo+
8
Vo-
5
8 Ohms
TS4994IS
2/31
Absolute Maximum RatingsTS4994
2Absolute Maximum Ratings
Table 1. Key parameters and their absolute maximum ratings
SymbolParameterValueUnit
VCC
T
T
R
Supply voltage
V
iInput Voltage
Operating Free Air Temperature Range
oper
Storage Temperature
stg
T
Maximum Junction Temperature
j
Thermal Resistance Junction to Ambient
thja
DFN10
Mini-SO8
PdPower Dissipationinternally limitedW
ESDHuman Body Model2kV
ESDMachine Model200V
Latch-up Immunity200mA
Lead Temperature (soldering, 10sec)260°C
1) All voltages values are measured with respect to the ground pin.
2) The magnitude of input signal must never exceed VCC + 0.3V / GND - 0.3V
3) The device is protected by a thermal shutdown active at 150°C
1
2
6V
GND to V
CC
V
-40 to + 85°C
-65 to +150°C
150°C
3
120
°C/W
215
Table 2. Operating conditions
SymbolParameterValueUnit
V
V
V
T
R
1) The minimum current consum ption (I
range.
2) When mounted on a 4-layer PCB.
Supply Voltage
CC
Standby Mode Voltage Input:
Standby Active LOW
SM
Standby Active HIGH
Standby Voltage Input:
Device ON (V
STB
Device OFF (V
Thermal Shutdown Temperature
SD
Load Resistor
R
L
Thermal Resistance Junction to Ambient
2
DFN10
THJA
=GND) or Device OFF (VSM=VCC)
SM
=GND) or Device ON (VSM=VCC)
SM
Mini-SO8
STANDBY
) is guaranteed when V
2.5 to 5.5V
V
=GND
SM
V
SM=VCC
1.5
≤ V
≤ VCC
STB
≤ V
G
ND
STB
≤ 0.4
1
150°C
≥ 8Ω
80
190
=GND or VCC (i.e. supply rails) for the whole temperature