NXP Semiconductors TFA9810 Operational manual

1. General description
The TFA9810 is a two-channel power comparator for high-efficiency class D audio
amplifier systems. It contains two full-bridge Bridge-Tied Load (BTL) power stages, drive
logic, protection control logic and full differential input comparators. By using this power
comparator a compact closed-loop self-oscillating digital amplifier system or open-loop
system can be built. The TFA9810 does not require a heat sink and operates using an
asymmetrical supply voltage.
2. Features
nStereo full-bridge power comparator for class D audio amplifier applications
nNo external heat sink required
nOperating voltage range: asymmetrical from 8 V to 20 V
nThermally protected
nZero dead-time switching
nCurrent-limiting (no audible interruptions)
3. Applications
nSelf-oscillating or open-loop class D audio amplifier applications
nFlat-panel television sets
nFlat-panel monitors
nMultimedia systems
nWireless speakers
nHigh-end CRT television sets
4. Quick reference data
TFA9810
Stereo full-bridge audio amplifier 2 x 12 W
Rev. 03 — 20 February 2008 Product data sheet
Table 1. Quick reference data
T
amb
= 25 ° C; V
P
= 12 V; f
osc
= 550 kHz; Figure 33 unless otherwise specified
Symbol Parameter Condition Min Typ Max Unit
VPsupply voltage VP= VDDPx −VSSPx 81220V
Ioff off-state current off mode - 110 200 µA
Iqquiescent current with load, filter and
snubbers connected -3545mA
ηpo output power
efficiency output power 2 x 9 W into 8 Ω;
Po=P
o(nom)
87 89 - %

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 2 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
5. Ordering information
Po(RMS) RMS output power RL= 8 Ω; VP= 12 V;
THD = 10 %;Twochannel
driven; no heat sink
required.
- 9.5 - W
Pooutput power VP= 12 V; RL= 8 Ω----
THD = 10 % 8.5 9.5 - W
THD = 1 % 6.5 7.5 - W
VP= 14 V; RL= 8 Ω;
THD = 10 %; thermally
limited
-15-W
VP= 16 V; RL= 8 Ω;
THD = 10 %; thermally
limited
-15-W
VP= 12 V; RL= 6 Ω;
THD = 10 %; thermally
limited
-12-W
VP= 12 V; RL= 4 Ω;
THD = 10 %; thermally
limited
-15-W
Table 1. Quick reference data
…continued
T
amb
= 25 ° C; V
P
= 12 V; f
osc
= 550 kHz; Figure 33 unless otherwise specified
Symbol Parameter Condition Min Typ Max Unit
Table 2. Ordering information
Type number Package
Name Description Version
TFA9810T SO32 SO32: plastic small outline package; 32 leads; body width 7.5 mm SOT287-1

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 3 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
6. Block diagram
Fig 1. Block diagram
27
26
25
30
29
28
VDDP1
VSSP1
22
BOOT1P
VDDP1
OUT1P
VSSP1
BOOT1N
OUT1N
STAB1
BOOT2P
STABI1
CONTROL
LOGIC 23
24
19
DRIVER
HIGH
20
21
VDDP2
VSSP2
VDDP2
OUT2P
VSSP2
BOOT2N
OUT2N
STAB2
STABI2
VDDA1
IN1P
IN1N
VSSA1
VDDA2
IN2P
IN2N
VSSA2
REFERENCE
PROTECTION
OVP
UVP
OCP
OTP
ODP
WP
HEATSPREADER
COMPARATOR 1
COMPARATOR 2
SO/OL
ENABLE
CDELAY
DIAG
TEST 11
4
2
3
5
10
6
7
8
13
15
14
12
1161732
VSSD(HW)
9
n.c.
TFA9810
010aaa016
CONTROL
LOGIC
DRIVER
HIGH
DRIVER
LOW
DRIVER
LOW
CONTROL
LOGIC
CONTROL
LOGIC
DRIVER
HIGH
DRIVER
LOW
DRIVER
HIGH
DRIVER
LOW
18
31

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 4 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
7. Pinning information
7.1 Pinning
The SO32 package has four corner leads. These leads (1, 16, 17, and 32) are internally
connected to the die pad and must be connected to VSSA in the application. Together with
the applied copper area on the Printed Circuit Board (PCB) these leads determine the
ambient temperature, which affects the thermal resistance of the junction.
7.2 Pin description
Fig 2. Pin configuration
TFA9810
SO32
VSSD(HW) VSSD(HW)
IN1P STAB1
IN1N VSSP1
VDDA1 BOOT1N
VSSA1 OUT1N
SO/OL BOOT1P
ENABLE OUT1P
CDELAY VDDP1
n.c. VDDP2
DIAG OUT2P
TEST BOOT2P
VSSA2 OUT2N
VDDA2 BOOT2N
IN2N VSSP2
IN2P STAB2
VSSD(HW) VSSD(HW)
010aaa017
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
18
17
20
19
22
21
24
23
26
25
32
31
30
29
28
27
Table 3. Pin description
Symbol Pin Description
VSSD(HW) 1, 16, 17,
32 Negative digital supply voltage and handle wafer
IN1P 2 Positive input comparator channel 1
IN1N 3 Negative input comparator channel 1
VDDA1 4 Positive analog supply voltage channel 1
VSSA1 5 Negative analog supply voltage channel 1
SO/OL 6 SO/OL input enables self-oscillating / open-loop configuration
ENABLE 7 Enable input to switch between SLEEP and OPERATING
CDELAY 8 CDELAY input determines the switch on/off timing
n.c. 9 Not connected
DIAG 10 Diagnostic output; open drain
TEST 11 Test signal input; for testing purposes only
VSSA2 12 Negative analog supply voltage channel 2
VDDA2 13 Positive analog supply voltage channel 2

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 5 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
8. Functional description
8.1 General
The TFA9810 is a dual-switching power comparator. It is the main building block for a
stereo high-efficiency Class D audio power amplifier system. It contains two full-bridge
BTL power stages, drive logic, protection-control logic and full differential input
comparators and references (see Figure 1). By using this power comparator a compact
closed-loop self-oscillating digital amplifier system or open-loop system can be built. A
second-order low-pass filter converts the Pulse Width Modulation (PWM) output signal
into an analog audio signal across the speaker.
8.2 Interfacing
The pins ENABLE and SO/OL control the operating mode of the TFA9810. Both the
ENABLE and the SO/OL pins refer to VSSD(HW).
When the SO/OL pin is connected to VSSA the TFA9810 is in self-oscillating mode: when
the SO/OL pin is floating the TFA9810 is in open-loop mode.
The TEST pin needs to be connected to VDDA in both situations.
The device has two modes: SLEEP and OPERATING.
IN2N 14 Negative input comparator channel 2
IN2P 15 Positive input comparator channel 2
STAB2 18 Decoupling of internal 11 V regulator for channel 2 drivers
VSSP2 19 Negative power-supply voltage channel 2
BOOT2N 20 Bootstrap high-side driver negative output channel 2
OUT2N 21 Negative output channel 2
BOOT2P 22 Bootstrap high-side driver positive output channel 2
OUT2P 23 Positive output channel 2
VDDP2 24 Positive supply voltage power channel 2
VDDP1 25 Positive power supply voltage channel 1
OUT1P 26 Positive output channel 1
BOOT1P 27 Bootstrap high-side driver positive output channel 1
OUT1N 28 Negative output channel 1
BOOT1N 29 Bootstrap high-side driver negative output channel 1
VSSP1 30 Negative supply voltage power channel 1
STAB1 31 Decoupling of internal 11 V regulator for channel 1 drivers
Table 3. Pin description
…continued
Symbol Pin Description
Table 4. SO/OL connections
Interfacing
SO/OL connected to Configuration
VSSD(HW) Self-oscillating
Open Open-loop

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 6 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
In SLEEP mode the TFA9810 is not biased and has a very low supply current.
When the TFA9810 is set to OPERATING mode the device is started via the start-up
sequence, which provides a pop-free start-up behavior. After start-up the reference
voltages STAB are present and the outputs start switching.
8.3 Input comparators
The input stages have a differential input and are optimized for low noise and low offset.
This results in maximum flexibility in the application.
8.3.1 Operating in self-oscillating configuration
The inputs (IN1P, IN1N, IN2P, IN2N) of the comparators are internally set to a voltage level
of 0.5VP, but only during the start-up sequence. In operating mode the inputs are
high-ohmic.
8.3.2 Operating in open-loop configuration
No internal voltages are applied to the inputs. The input pins (IN1P, IN1N, IN2P, IN2N) are
pulled down to VSSA level by internal resistors.
8.4 Diagnostic
The DIAG output is an open-drain output. The maximum current is 2 mA. Whenever one
of the protections is triggered the DIAG output is activated low. The DIAG output refers to
VSSD.
8.5 Protections
Overtemperature, overcurrent, overvoltage, undervoltage, overdissipation sensors, and
window protection are included in the TFA9810. When one of these sensors exceeds its
threshold level either the output power stage is switched off and the outputs (OUT1N,
OUT1P, OUT2N, OUT2P) become floating, or the TFA9810 shuts down and starts up
immediately.
•OverTemperature Protection (OTP)
If the junction temperature (Tj) exceeds a threshold level of about 150 °C then the
outputs become floating. The device will start switching again after 5 µs and when the
temperature is below 150 °C. This is thermal limitation without audible interruptions.
•OverCurrent Protection (OCP)
If the output current exceeds the maximum output current threshold level the output
becomes floating. The device will start switching again after 5 µs. This is current
limitation without audible interruptions.
Table 5. Start-up
Interfacing
ENABLE [V] Mode
ENABLE < 0.8 V SLEEP
ENABLE > 3 V OPERATING

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 7 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
•OverVoltage Protection (OVP)
When the supply voltage applied to the TFA9810 exceeds the maximum supply
voltage threshold level the device will shut down. The device will restart when the
supply voltage is within the operating range.
•UnderVoltage Protection (UVP)
When the supply voltage applied to the TFA9810 falls below the minimum supply
voltage threshold level the device will shut down. The device will restart when the
supply voltage is within the operating range.
•OverDissipation Protection (ODP)
The ODP in the TFA9810 is a combination of two protections. Exceeding a
temperature threshold level of 135 °C an internal pre-warning is generated. When an
overcurrent is detected during the pre-warning the device will shut down. When the
ENABLE pin is high the TFA9810 will restart automatically. The restart sequence
(switch-off →switch-on) will take 200 ms to 500 ms.
•Window Protection (WP)
During start-up, if one of the outputs is shorted to VSS or VDD the device will not start.
This is an effective measure to protect the device against shorts between the outputs
(before the filter) and the ground or supply lines. The supply must be switched off prior
to removing any short. The WP protects the device against failure during board
assembly.
Table 6. Overview protections
Protections
Symbol Condition DIAG Outputs Recovering
OTP Tj> 150 °C LOW Floating Automatic, after 5 µs and Tj< 150 °C
OCP IO> IORM LOW Floating Automatic, after 5 µs and IO< IORM
OVP VP> 20 V LOW Floating Restart (switch-off →switch-on when VP< 20 V)
UVP VP< 8 V LOW Floating Restart (switch-off →switch-on when VP> 8 V)
ODP Tj> 135 °C and IO> IORM LOW Floating Restart (switch-off →switch-on when
Tj< 135 °CorI
O<I ORM)
WP OUTX > VDDA - 1 V or
OUTX < VSSA + 1 V LOW

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 8 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
8.6 Start-up sequence
9. Internal circuitry
Fig 3. Start-up sequence
SLEEP START-UP OPERATING FAULT RESTART OPERATING SHUT-DOWN SLEEP
FLOATING
AUDIO
PWM
010aaa018
AUDIO
PWM
FLOATING
VP
ENABLE
STAB1
CDELAY
V IN x
OUT x
AUDIO
DIAG
Fig 4. Internal circuitry 0001
22 V
VDDA
VSSA
1,16, 17, 32
010aaa024

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 9 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
Fig 5. Internal circuitry 0002
Fig 6. Internal circuitry 0003
Fig 7. Internal circuitry 0004
hvp VSSA
135 kΩ
135 kΩ
5.5 V
5.5 V
VSSA1
VDDA1
2
3
010aaa025
22 V
4
5
010aaa026
110 kΩ
6
VSSA
010aaa027
VDDA1
VSSA1
VDDA1
50 µA

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 10 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
Fig 8. Internal circuitry 0005
Fig 9. Internal circuitry 0006
Fig 10. Internal circuitry 0007
3 kΩ
VSSA
250 nA
7
VDDA1
010aaa028
8
VDDA1
DISCHARGE
VSSA1
010aaa029
2 nA
200 nA 5 kΩ
VDDA1
VSSA1 V
SSD
10
010aaa030

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 11 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
Fig 11. Internal circuitry 0008
Fig 12. Internal circuitry 0009
Fig 13. Internal circuitry 0010
Fig 14. Internal circuitry 0011
VDDA1
VSSA1
11
010aaa031
13 kΩ
VSSA2
VDDA2
14
15
hvp
130 kΩ
130 kΩ
VSSA2
010aaa033
5.5 V
5.5 V
VSSD
100 mA
18
VDDA2
12 V
010aaa034

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 12 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
Fig 15. Internal circuitry 0012
Fig 16. Internal circuitry 0013
Fig 17. Internal circuitry 0014
Fig 18. Internal circuitry 0015
19
24
23.5 V
010aaa035
12 V
OUT2N
20
010aaa036
VDDP2
21
VSSP2
010aaa037
12 V
OUT2P
22
010aaa038

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 13 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
Fig 19. Internal circuitry 0016
Fig 20. Internal circuitry 0017
Fig 21. Internal circuitry 0018
Fig 22. Internal circuitry 0019
VDDP2
23
VSSP2
010aaa039
23.5 V
25
30
010aaa040
VDDP1
26
VSSP1
010aaa041

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 14 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
10. Limiting values
Fig 23. Internal circuitry 0020
Fig 24. Internal circuitry 0021
Fig 25. Internal circuitry 0022
VDDP1
28
VSSP1
010aaa043
12 V
OUT1N
29
010aaa044
VSSD
100 mA
31
VDDA1
12 V
010aaa045
Table 7. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
VPsupply voltage asymmetrical −0.3 +23 V
IORM repetitive peak output current 3 - A
Tjjunction temperature - +150 °C
Tstg storage temperature −55 +150 °C
Tamb ambient temperature −40 +85 °C
Pmax maximum power dissipation - 2.5 W

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 15 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
11. Thermal characteristics
[1] Measured in a JEDEC high K-factor test board (standard EIA/JESD 51-7) in free air with natural convection.
[2] Strongly depends on where the measurement is taken on the case.
12. Characteristics
12.1 Static characteristics
Vxvoltage on pin x DIAG VSS −0.3 +12 V
IN1P - IN1N −12 +12 V
IN2P - IN2N −12 +12 V
all other pins VSS −0.3 VDD + 0.3 V
Vesd electrostatic discharge voltage VINX with
respect to
other pins
−1500 +1500 V
all other pins −2000 +2000 V
Table 7. Limiting values
…continued
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
Table 8. Characteristics
Symbol Parameter Conditions Min Typ Max Unit
Rth(j-a) thermal resistance
from junction to
ambient
SO32. JEDEC test board
SO32. Two-layer application
board
[1] -
-41 44 44 -K/W K/W
Ψj-lead thermal
characterization
parameter from
junction to lead
SO32 [1] 30 K/W
Ψj-top thermal
characterization
parameter from
junction to top of
package
SO32 [1] [2] 4 8 K/W
Table 9. Static characteristics
T
amb
= 25 ° C; V
P
= 12 V; f
osc
= 550 kHz; Figure 33 unless otherwise specified
Symbol Parameter Conditions Min Typ Max Unit
Supply voltage
VPsupply voltage VP= VDDPx −VSSPx 8 1220V
Ioff off-state current off mode - 110 200 µA
Iqquiescent current with load, filter, and snubbers
connected - 3545mA
ENABLE input
VIL LOW-level input voltage with respect to VSSD −0.3 - +0.8 V
VIH HIGH-level input voltage with respect to VSSD 3- V
PV

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 16 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
[1] Current limiting concept: in overcurrent condition no interruption of the audio signal in case of impedance drop.
12.2 Dynamic characteristics
IIinput current VI= 5 V - 1 20 µA
SO/OL input
VIL LOW-level input voltage with respect to VSSD - - 0.4 V
VIH HIGH-level input voltage with respect to VSSD 3 4 4.5 V
STABI
VSTABI voltage on pin STABI with respect to VSS 10 11 12 V
Comparator full-differential input stage
Voffset(i)(eq) equivalent input offset
voltage --1mV
20 Hz < f < 20 kHz - - 15 µV
Vcm common mode voltage VSSA + 3 - VDDA −1V
IIB input bias current - - 1 µA
OverTemperature Protection (OTP)
Tprot protection temperature 150 - - °C
OverVoltage Protection (OVP)
Vth(ovp) overvoltage protection
threshold voltage level internal fixed 20 21.5 23 V
UnderVoltage Protection (UVP)
VP(uvp) undervoltage protection
supply voltage level internal fixed 7 7.5 8 V
OverCurrent Protection (OCP)
IO(ocp) overcurrent protection
output current [1] 3 3.5 - A
Window Protection (WP)
VOoutput voltage high level - VDDA − 1- V
low level - VSSA + 1 - V
Table 9. Static characteristics
…continued
T
amb
= 25 ° C; V
P
= 12 V; f
osc
= 550 kHz; Figure 33 unless otherwise specified
Symbol Parameter Conditions Min Typ Max Unit
Table 10. Dynamic characteristics
T
amb
= 25 ° C; V
P
= 12 V; R
L
= 8 Ω ;Figure 33 unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
PWM output
trrise time - 10 - ns
tffall time - 10 - ns

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 17 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
[1] High-side and low-side power switch have the same series resistance.
[2] Output power measured across the loudspeaker load. Output power is measured indirectly via RDSon.
12.3 AC characteristics measured in a typical application
tresp response time transition PWM output from
LOW to HIGH
VI= 70 mV
VI= 3.3 V
-
-60 50 - -ns ns
transition PWM output from
HIGH to LOW
VI= 70 mV
VI= 3.3 V
-
-60 50 - -ns ns
tw(min) minimum pulse width PWM output - 60 - ns
RDSon drain-source on-state
resistance [1] - 0.28 0.35 Ω
ηpo output power
efficiency output power 2x9Winto 8 Ω. Po= Po(nom)
[2] 87 89 - %
Table 10. Dynamic characteristics
…continued
T
amb
= 25 ° C; V
P
= 12 V; R
L
= 8 Ω ;Figure 33 unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
Table 11. AC characteristics measured in typical application
T
amb
= 25 ° C; V
P
= 12 V; R
L
= 8 Ω; f
osc
= 550 kHz; Figure 33 unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
VPsupply voltage VP= VDDPx −VSSPx 8 1220V
Po(RMS) RMS output power RL= 8 Ω; VP= 12 V;
THD = 10 %; Two channel
driven; no heat sink required.
- 9.5 - W
Pooutput power VP= 12 V; RL= 8 Ω
THD = 10 % 8.5 9.5 - W
THD = 1 % 6.5 7.5 - W
VP= 14 V; RL= 8 Ω;
THD = 10 %; thermally limited -12-W
VP= 16 V; RL= 8 Ω;
THD = 10 %; thermally limited -15-W
VP= 12 V; RL= 6 Ω;
THD = 10 %; thermally limited -12-W
VP= 12 V; RL= 4 Ω;
THD = 10 %; thermally limited -15-W
THD+N total harmonic
distortion-plus-noise Pois 1 W; f = 1 kHz; AES17
brick-wall filter - 0.04 0.1 %
ηpo output power
efficiency Po= 9 W 87 89 - %
Gv(cl) closed-loop voltage
gain VI= 100 mV (RMS); fi= 1 kHz 19 19.7 21 dB
Vn(o) output noise voltage Inputs shorted;
AES17 brick-wall filter - 150 - µV

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 18 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
[1] Minimum value determined by R5, R10, R17, R22 equalling +1 % and R7, R14, R18, R20 equalling −1 %.
13. Quality specification
In accordance with SNW-FQ-611-E, ‘if this type is used as an audio amplifier’. The
number of the quality specification can be found in the Quality Reference Handbook. The
handbook can be ordered using the code 9398 510 63011.
14. Application information
14.1 Output power estimation
For BTL configuration the output power just before clipping can be estimated using
Equation 1:
(1)
Where,
•VP= supply voltage (VDDPx −VSSPx) [V]
•RL= load resistance [Ω]
•RDSon = drain-source on-state resistance [Ω]
•Rs= series resistance [Ω]
•Po0.5 % = output power at the THD level of 0.5 % [W]
The output power at 10 % THD can be estimated by using Equation 2:
(2)
Figure 26 and Figure 27 below show the estimated output power at THD = 0.5 % and
THD = 10 % as a function of the BLT supply voltage for different load impedances.
S/N signal-to-noise ratio Vo= 10 V (RMS); gain 20 dB - 96 - dB
SVRR supply voltage ripple
rejection Vripple = 2 V(p-p); fi= 1 kHz [1] 34 45 - dB
αcs channel separation Po= 1 W; fi= 1 kHz 55 70 - dB
Table 11. AC characteristics measured in typical application
…continued
T
amb
= 25 ° C; V
P
= 12 V; R
L
= 8 Ω; f
osc
= 550 kHz; Figure 33 unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
BTL : Po0.5 %
RL
RL2+RDSon Rs +()×
------------------------------------------------------VP
×2
2R
L
×
---------------------------------------------------------------------------------
=
Po10 % 1.25 P×o0.5 % =

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 19 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
14.2 Output current limiting
The peak output current is internally limited above a level of 3 A minimum. During normal
operation the output current should not exceed this threshold level of 3 A, otherwise the
output signal will be distorted. The peak output current in BTL can be estimated using
Equation 3:
(3)
Where:
•VP= supply voltage (VDDPx −VSSPx) [V].
(1) RL= 4 Ω
(2) RL= 6 Ω
(3) RL= 8 Ω
Fig 26. BTL output power as function of supply voltage: THD = 0.5 %. 3 A
(1) RL= 4 Ω
(2) RL= 6 Ω
(3) RL= 8 Ω
Fig 27. BTL output power as function of supply voltage: THD = 10 %. 3 A
(1)
(2)
(3)
VP(V)
8 201612
010aaa019
10
15
5
20
25
Po
(W)
0
(1)
(2)
(3)
VP(V)
8 201612
010aaa020
10
20
30
Po
(W)
0
IOmax VP
RL2R
DSon Rs
+()×+
------------------------------------------------------3 A≤≤

TFA9810_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 February 2008 20 of 29
NXP Semiconductors TFA9810
Audio amplifier 2 x 12 W
•RL= load resistance [Ω].
•RDSon = drain-source on-state resistance [Ω].
•Rs= series resistance [Ω].
Example:
A4Ωspeaker in BTL configuration can be used up to a supply voltage of 12 V without
running into current limiting. Current limiting (clipping) will avoid audio holes, but it causes
a sound distortion similar to voltage clipping.
14.3 Speaker configuration and impedance
For a flat-frequency response (second-order Butterworth filter) it is necessary to change
the low-pass filter components LLC and CLC according to the speaker configuration and
impedance. Table 12 shows the practical required values:
14.4 Differential input
For a high common-mode rejection ratio and a maximum of flexibility in the application,
the audio inputs of the application are fully differential.
The input configuration for a differential-input application is illustrated in Figure 28.
14.5 Single-ended input
When using an audio source with a single-ended ‘out’, it is important to connect the IN1N
from the application board to the VSS/GND of the audio source (e.g. Audio DSP).
The input configuration for single-ended ‘in’ application is illustrated in Figure 29.
Table 12. Filter component values
Configuration Impedance [Ω] LLC [µF] CLC [nF]
BTL 4 10 1500
6 16 1000
8 22 680
Fig 28. Input configuration for differential input
IN1P
IN1N
AUDIO
DSP
OUT1P
OUT1N
010aaa021
+
−
VSS