TS4962
2.8 W filter-free mono class D audio power amplifier
Features
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■
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Operating from V
CC
= 2.4 V to 5.5 V
Standby mode active low
Output power: 2.8 W into 4
Ω
and 1.7 W into
8
Ω
with 10% THD+N maximum and 5 V power
supply
Output power: 2.2 W at 5 V or 0.7 W at 3.0 V
into 4
Ω
with 1% THD+N maximum
Output power: 1.4 W at 5 V or 0.5 W at 3.0 V
into 8
Ω
with 1% THD+N maximum
Adjustable gain via external resistors
Low current consumption 2 mA at 3 V
Efficiency: 88% typical
Signal to noise ratio: 85 dB typical
PSRR: 63 dB typical at 217 Hz with 6 dB gain
PWM base frequency: 280 kHz
Low pop & click noise
Thermal shutdown protection
Available in DFN8 3 x 3 mm package
1
2
3
4
DFN8 3 x 3 mm
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TS4962IQT pinout
8
EXPOSED
PAD
7
6
5
Applications
■
■
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Cellular phones
PDAs
Notebook PCs
The gain of the device can be controlled via two
external gain setting resistors. Pop & click
reduction circuitry provides low on/off switch noise
while allowing the device to start within 5 ms. A
standby function (active low) enables the current
consumption to be reduced to 10 nA typical.
Description
The TS4962 is a differential class-D BTL power
amplifier. It can drive up to 2.2 W into a 4
Ω
load
and 1.4 W into an 8
Ω
load at 5 V. It achieves
outstanding efficiency (88% typ.) compared to
standard AB-class audio amps.
January 2010
Doc ID 10968 Rev 8
1/44
www.st.com
44
Contents
TS4962
Contents
1
2
3
Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 3
Application overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1
Electrical characteristics curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
Differential configuration principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Gain in typical application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Common-mode feedback loop limitations . . . . . . . . . . . . . . . . . . . . . . . . 31
Low frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Decoupling of the circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Wake-up time (t
WU
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Shutdown time (t
STBY
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Consumption in standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Single-ended input configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Output filter considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Several examples with summed inputs . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.11.1
4.11.2
Example 1: dual differential inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Example 2: one differential input plus one single-ended input . . . . . . . . 36
5
6
7
8
9
Demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2/44
Doc ID 10968 Rev 8
TS4962
Absolute maximum ratings and operating conditions
1
Absolute maximum ratings and operating conditions
Table 1.
Symbol
V
CC
V
i
T
oper
T
stg
T
j
R
thja
Pd
Absolute maximum ratings
Parameter
Supply voltage
(1) (2)
Input voltage
(3)
Operating free air temperature range
Storage temperature
Maximum junction temperature
Thermal resistance junction to ambient
DFN8 package
Power dissipation
Human body model
(5)
Value
6
GND to V
CC
-40 to + 85
-65 to +150
150
120
Internally limited
(4)
2
200
kV
V
Unit
V
V
°C
°C
°C
°C/W
ESD
Machine model
(6)
Charged device model
(7)
Latch-up
V
STBY
Latch-up immunity
Standby pin maximum voltage
(8)
Lead temperature (soldering, 10sec)
200
GND to V
CC
260
mA
V
°C
1. Caution: this device is not protected in the event of abnormal operating conditions such as short-circuiting
between any one output pin and ground or between any one output pin and V
CC
, and between individual
output pins.
2. All voltage values are measured with respect to the ground pin.
3. The magnitude of the input signal must never exceed V
CC
+ 0.3 V/GND - 0.3 V.
4. Exceeding the power derating curves during a long period will provoke abnormal operation.
5. Human body model: a 100 pF capacitor is charged to the specified voltage, then discharged through a
1.5 kΩ resistor between two pins of the device. This is done for all couples of connected pin combinations
while the other pins are floating.
6. Machine model: a 200 pF capacitor is charged to the specified voltage, then discharged directly between
two pins of the device with no external series resistor (internal resistor < 5
Ω).
This is done for all couples of
connected pin combinations while the other pins are floating.
7. Charged device model: all pins and the package are charged together to the specified voltage and then
discharged directly to the ground through only one pin. This is done for all pins.
8. The magnitude of the standby signal must never exceed V
CC
+ 0.3 V/GND - 0.3 V.
Table 2.
Dissipation ratings
Derating factor
20 mW/°C
Power rating at 25°C
2.5 W
Power rating at 85°C
1.3 W
Package
DFN8
Doc ID 10968 Rev 8
3/44
Absolute maximum ratings and operating conditions
Table 3.
Symbol
V
CC
V
IC
V
STBY
R
L
R
thja
TS4962
Operating conditions
Parameter
Supply voltage
(1)
Common mode input voltage range
(2)
Standby voltage input:
(3)
Device ON
Device OFF
Load resistor
Thermal resistance junction to ambient
DFN8 package
(5)
Value
2.4 to 5.5
0.5 to V
CC
-0.8
1.4
≤
V
STBY
≤
V
CC
GND
≤
V
STBY
≤
0.4
(4)
≥
4
50
Unit
V
V
V
Ω
°C/W
1. For V
CC
between 2.4 V and 2.5 V, the operating temperature range is reduced to 0°C
≤
T
amb
2. For V
CC
between 2.4V and 2.5V, the common mode input range must be set at V
CC
/2.
3. Without any signal on V
STBY
, the device will be in standby.
4. Minimum current consumption is obtained when V
STBY
= GND.
5.
When mounted on a 4-layer PCB.
≤
70°C.
4/44
Doc ID 10968 Rev 8
TS4962
Application overview
2
Application overview
Table 4.
External component information
Functional description
Bypass supply capacitor. Install as close as possible to the TS4962 to
minimize high-frequency ripple. A 100 nF ceramic capacitor should be added
to enhance the power supply filtering at high frequencies.
Input resistor used to program the TS4962’s differential gain
(gain = 300 kΩ/R
in
with R
in
in kΩ).
Because of common-mode feedback, these input capacitors are optional.
However, they can be added to form with R
in
a 1st order high-pass filter with
-3 dB cut-off frequency = 1/(2*
π
*R
in
*C
in
).
Component
C
S
R
in
Input capacitor
Table 5.
Pin description
Pin name
STBY
NC
IN+
IN-
OUT+
VCC
GND
OUT-
Exposed pad
Description
Standby input pin (active low)
No internal connection pin
Positive input pin
Negative input pin
Positive output pin
Power supply input pin
Ground input pin
Negative output pin
Exposed pad can be connected to ground (pin 7) or left
floating
Pin number
1
2
3
4
5
6
7
8
Doc ID 10968 Rev 8
5/44
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