PHILIPS TFA9812

TFA9812
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
Preliminary data sheet
1. General description
The TFA9812 is a high-efficiency Bridge Tied Load (BTL) stereo Class-D audio amplifier
with a digital I2S audio input. It is available in a HVQFN48 package with exposed die
paddle. The exposed die paddle technology enhances the thermal and electrical
performances of the device.
The TFA9812 features digital sound processing and audio power amplification. It supports
I2C control mode and Legacy mode. In Legacy mode I2C involvement is not needed
because the key features are controlled by hardware pin connections.
A continuous time output power of 2 × 12 W (RL = 8 Ω, VDDP = 15 V) is supported without
an external heat sink. Due to the implementation of a programmable thermal foldback
even for high supply voltages, higher ambient temperatures, and/or lower load
impedances, the device operates without sound interrupting behavior.
TFA9812 is designed in such a way that it starts up easily (no special power-up sequence
required). It features various soft and hard impact protection mechanisms to ensure an
application that is both user friendly and robust.
A modulation technique is applied for the TFA9812, which supports common mode choke
approach (1 common mode choke only per BTL amplifier stage). This minimizes the
number of external components.
2. Features
2.1 General features
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3.3 V and 8 V to 20 V external power supply
High efficiency and low power dissipation
Speaker outputs fully short circuit proof across load, to supply lines and ground
Pop noise free at power-up/power-down and sample rate switching
Low power sleep mode
Overvoltage and undervoltage protection on the 8 V to 20 V power supply
Undervoltage protection on the 3.3 V power supply
Overcurrent protection (no audible interruptions)
Overdissipation protection
Thermally protected and programmable thermal foldback
Clock error protection
I2C mode control or Legacy mode (i.e. no I2C) control
Four different I2C addresses supported
Internal Phase-Locked Loop (PLL) without using external components
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
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No high system clock required (PLL is able to lock on BCK)
No external heat sink required
5 V tolerant digital inputs
Supports dual coil inductor application
Easy application and limited external components required
2.2 DSP features
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Digital parametric 10-band equalizer
Digital volume control per channel
Selectable +24 dB gain boost
Analog interface to digital volume control in Legacy mode
Digital clip level control
Soft and hard mute
Thermal foldback threshold temperature control
De-emphasis
Output power limiting control
Polarity switch
Four Pulse Width Modulation (PWM) switching frequency settings
2.3 Audio data input interface format support
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Master or slave Master Clock (MCLK), Bit Clock (BCK) and Word Select (WS) signals
Philips I2S, standard I2S
Japanese I2S, Most Significant Bit (MSB) justified
Sony I2S, Least Significant Bit (LSB) justified
Sample rates from 8 kHz to 192 kHz
3. Applications
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Digital-in Class-D audio amplifier applications
CRT and flat-panel television sets
Flat-panel monitors
Multimedia systems
Wireless speakers
Docking stations for MP3 players
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
2 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
4. Quick reference data
Table 1.
Quick reference table
Unless specified otherwise, VDDA = VDDP = 12 V, VSSP1 = VSSP2 = 0 V, VDDA(3V3) = VDDD(3V3) = 3.3 V,
VSS1 = VSS2 = REFD = REFA = 0 V, Tamb = 25 °C, RL = 8 Ω, fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz,
24-bit I2S input data, MCLK clock mode, typical application diagram (Figure 13).
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
General
VDDA
analog supply
voltage
8
12
20
V
VDDP
power supply
voltage
8
12
20
V
VDDA(3V3)
analog supply
voltage (3.3 V)
3.0
3.3
3.6
V
VDDD(3V3)
digital supply
voltage (3.3 V)
3.0
3.3
3.6
V
IP
supply current
IDDA(3V3)
analog supply
current (3.3 V)
soft mute mode, with load,
filter and snubbers
connected
[1]
-
38
45
mA
sleep mode
[1]
-
160
270
µA
I2S slave mode
-
2
4
mA
I2S
-
4
6
mA
VDDA = VDDP = 12 V
-
120
-
µA
VDDA = VDDP = 1 V
-
40
70
µA
I2S slave mode
-
15
25
mA
I2S
-
25
40
mA
-
4
30
µA
operating mode
master mode
sleep mode
IDDD(3V3)
digital supply
current (3.3 V)
operating mode
master mode
sleep mode;
DATA = WS = BCK =
MCLK = 0 V
Po(RMS)
RMS output power Continuous time output power per channel; THD = 10 %;
RL = 8 Ω
VDDA = VDDP = 12 V
-
8.3
-
W
VDDA = VDDP = 13.5 V
-
10
-
W
VDDA = VDDP = 15 V
-
12
-
W
Short time (≤ 10 s) output power per channel; THD = 10 %;
RL = 8 Ω
VDDA = VDDP = 17 V
ηpo
[1]
output power
efficiency
RL = 8 Ω; Po(RMS) = 8.3 W
15
-
W
-
88
-
%
IP is the current through the analog supply voltage (VDDA) pin added to the current through the power supply
voltage (VDDP) pin.
TFA9812_1
Preliminary data sheet
-
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
3 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
5. Ordering information
Table 2.
Ordering information
Type number
TFA9812HN
Package
Name
Description
Version
HVQFN48
plastic thermal enhanced very thin quad flat package; no leads;
48 terminals; body 7 × 7 × 0.85 mm
SOT619-8
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
4 of 66
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TEST1
TEST2
AVOL
43
32
7
VDDD(3V3)
VDDA(3V3)
40
3
VDDA
6
15
18, 19
REGISTER
ADDRESS
HEX 01
PHASED
LOCKED
LOOP
XTALIN 1
XTALOUT 2
CLOCK
PROTECTION
LP
UFP
OFP
IBP
OSCILLATOR
MCLK 47
1
TFA9812
DRIVER
LOW
PWM
CONTROLLER
STAB1
DRIVER
HIGH
23, 24 OUT1N
INTERPOLATION
FILTER AND
DE-EMPHASIS
GAIN
26, 27
VSSP1
28 STAB1
POWER
LIMITER
22 BOOT2P
VDDP
DRIVER
HIGH
20, 21 OUT2P
CONTROL
LOGIC
DRIVER
LOW
PWM
CONTROLLER
POWERUP 31
STAB2
ENABLE 33
VSSP2
12 BOOT2N
VDDP
GAIN 34
CSEL 35
ADSEL2/PLIM2 36
ADSEL1/PLIM1 37
CONTROL
INTERFACE
SCL/SFOR 38
DRIVER
HIGH
13, 14 OUT2N
CONTROL
LOGIC
REFERENCES
DRIVER
LOW
VSSP2
9
29
DIAG
Fig 1.
TFA9812 block diagram
41
42
CDELAY STABD
REFD
30
4
STABA
5
REFA
8
EXPOSED DIE PADDLE VSS1
STAB2
48
VSS2
010aaa217
TFA9812
5 of 66
© NXP B.V. 2008. All rights reserved.
SDA/MS 39
PROTECTION
OVP
UVP
OCP
OTP
ODP
WP
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
VOLUME
CONTROL
AND SOFT
MUTE
10-BAND
PARAMETRIC
EQUALIZER
25 BOOT1N
VDDP
DRIVER
LOW
SERIAL
AUDIO
DATA 44 INTERFACE
10, 11 VSSP2
CSEL
CONTROL
LOGIC
WS 45
VDDP
16, 17 OUT1P
CONTROL
LOGIC
THERMAL
FOLDBACK
BCK 46
BOOT1P
DRIVER
HIGH
ADC
0
NXP Semiconductors
TFA9812_1
Preliminary data sheet
6. Block diagram
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Figure 1 shows the block diagram of the TFA9812. For a detailed description of the audio
signal path see Section 8.1.
7. Pinning information
37 ADSEL1/PLIM1
38 SCL/SFOR
40 VDDD(3V3)
39 SDA/MS
41 STABD
42 REFD
43 TEST2
44 DATA
45 WS
46 BCK
terminal 1
index area
47 MCLK
48 VSS2
7.1 Pinning
XTALIN
1
36 ADSEL2PLIM2
XTALOUT
2
35 CSEL
VDDA(3V3)
3
34 TEST3
STABA
4
33 ENABLE
REFA
5
32 AVOL
VDDA
6
TEST1
7
VSS1
8
29 DIAG
STAB2
9
28 STAB1
31 POWERUP
TFA9812HN
30 CDELAY
VSSP2 10
27 VSSP1
VSSP2 11
26 VSSP1
OUT1N 24
OUT1N 23
BOOT1P 22
OUT1P 21
OUT1P 20
VDDP 19
VDDP 18
OUT2P 17
OUT2P 16
BOOT2P 15
OUT2N 14
25 BOOT1N
OUT2N 13
BOOT2N 12
010aaa218
Transparent top view
Fig 2.
Table 3.
Pin configuration, transparent top view
Pinning description TFA9812
Pin
Symbol
Type
Description
1
XTALIN
I
Crystal oscillator input
2
XTALOUT
O
Crystal oscillator output
3
VDDA(3V3)
P
Analog supply voltage (3.3 V)
4
STABA
O
1.8 V analog stabilizer output
5
REFA
P
Analog reference voltage
6
VDDA
P
Analog supply voltage (8 V to 20 V)
7
TEST1
I
Test signal input 1. For test purposes only (connect to VSS)
8
VSS1
P
PCB ground reference
9
STAB2
O
Decoupling of internal 11 V regulator for channel 2 drivers
10
VSSP2
P
Negative power supply voltage for channel 1 and channel 2
11
VSSP2
P
Negative power supply voltage for channel 1 and channel 2
12
BOOT2N
O
Bootstrap high-side driver negative PWM output channel 2
13
OUT2N
O
Negative PWM output channel 2
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
6 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 3.
Pinning description TFA9812 …continued
Pin
Symbol
Type
Description
14
OUT2N
O
Negative PWM output channel 2
15
BOOT1P
O
Bootstrap high-side driver positive PWM output channel 1
16
OUT1P
O
Positive PWM output channel 1
17
OUT1P
O
Positive PWM output channel 1
18
VDDP
P
Positive power supply voltage (8 V to 20 V)
19
VDDP
P
Positive power supply voltage (8 V to 20 V)
20
OUT2P
O
Positive PWM output channel 2
21
OUT2P
O
Positive PWM output channel 2
22
BOOT2P
O
Bootstrap high-side driver positive PWM output channel 2
23
OUT1N
O
Negative PWM output channel 1
24
OUT1N
O
Negative PWM output channel 1
25
BOOT1N
O
Bootstrap high-side driver negative PWM output channel 1
26
VSSP1
P
Negative power supply voltage for channel 1 and channel 2
27
VSSP1
P
Negative power supply voltage for channel 1 and channel 2
28
STAB1
O
Decoupling of internal 11 V regulator for channel 1 drivers
29
DIAG
O
Fault mode indication output (open-drain pin)
30
CDELAY
I
Timing reference
31
POWERUP
I
Power-up pin to switch between Sleep and other operational
modes
32
AVOL
I
Analog volume control (Legacy mode)
33
ENABLE
I
Enable input to switch between 3-state and other
operational modes
34
GAIN
I
Gain selection input to select between 0 dB and +24 dB
gain (Legacy mode)
35
CSEL
I
Control selection input to select between Legacy mode
(no I2C bus control) and I2C bus control
36
ADSEL2/PLIM2 I
Address selection in I2C mode input 2, power limiter
selection input 2 in Legacy mode
37
ADSEL1/PLIM1 I
Address selection in I2C mode input 1, power limiter
selection input 1 in Legacy mode
38
SCL/SFOR
I
I2C bus clock input in I2C mode, I2S serial data format
selection input in Legacy mode
39
SDA/MS
I/O
I2C bus data input and output in I2C mode, master/slave
selection input in Legacy mode
40
VDDD(3V3)
P
Digital supply voltage (3.3 V)
41
STABD
O
1.8 V digital stabilizer output
42
REFD
P
Digital reference voltage
43
TEST2
I
Test signal input 2; for test purposes only (connect to VSS)
44
DATA
I
I2S bus data input
45
WS
I/O
I2S bus word select input (I2S slave mode) or output (I2S
master mode)
46
BCK
I/O
I2S bus bit clock input (I2S slave mode) or output (I2S
master mode)
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
7 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 3.
Pinning description TFA9812 …continued
Pin
Symbol
Type
Description
47
MCLK
I/O
Master clock input (I2S slave mode) or output (I2S master
mode)
48
VSS2
P
PCB ground reference
P
PCB ground reference
Exposed
die-paddle
8. Functional description
8.1 General
The TFA9812 is a high-efficiency stereo BTL Class-D amplifier with a digital I2S audio
input. It supports all commonly used I2S formats.
Figure 1 shows the functional block diagram, which includes the key function blocks of the
TFA9812. In the digital domain the audio signal is processed and converted to a pulse
width modulated signal using BD modulation. A BTL configured power comparator carries
out power amplification.
The audio signal processing path is as follows:
1. The Digital Audio Input (DAI) block translates the I2S (-like) input signal into a
standard internal stereo audio stream.
2. The 10-band parametric equalizer can optionally equalize the stereo audio stream.
Both channels have separate equalization streams. It can be used for speaker transfer
curve compensation to optimize the audio performance of applied speakers.
3. Volume control in the TFA9812 is done by attenuation. The attenuation depends on
the volume control settings and the thermal foldback value. Soft mute is also arranged
at this part. In Legacy mode the volume control is done by an on-board
Analog-to-Digital Converter (ADC) which measures the analog voltage on pin 32.
4. The interpolation filter interpolates from 1 fs to the PWM controller sample rate
(2048 fs at 44.1 kHz) by cascading FIR filters.
5. The gain block can boost the signal with 0 dB or +24 dB. Four specific gain settings
are also provided in this block. These specific gain settings are related to maximum
clip levels of < 0.5 %, 10 %, 20 % or 30 % THD at the TFA9812 output. These
maximum clip levels are only valid with the gain boost set to 0 dB and a 0 dBFS input
signal.
6. The power limiter limits the maximum output signal of the TFA9812. The power limiter
settings are 0 dB, −1.5 dB, −3 dB, and −4.5 dB. This function can be used to reduce
the maximum output power delivered to the speakers at a fixed supply voltage and
speaker impedance.
7. The PWM controller block transforms the audio signal into a BD-modulated PWM
signal. The BD-modulation provides a high signal-to-noise performance and
eliminates clock jitter noise.
8. Via four differential comparators the PWM signals are amplified by two BTL power
output stages. By default the left audio signal is connected to channel 1 and the right
audio signal to channel 2.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
8 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
The block control defines the operational control settings of the TFA9812 in line with the
actual I2C settings and the pin-controlled settings.
The PLL block creates the system clock and can take the I2S BCK, the MCLK or an
external crystal as reference source.
The following protections are built into the TFA9812:
•
•
•
•
•
•
•
•
•
•
•
•
Thermal Foldback (TF)
OverTemperature Protection (OTP)
OverCurrent Protection (OCP)
OverVoltage Protection (OVP)
UnderVoltage Protection (UVP)
Window Protection (WP)
Lock Protection (LP)
UnderFrequency Protection (UFP)
OverFrequency Protection (OFP)
Invalid BCK Protection (IBP)
DC-blocking
ElectroStatic Discharge (ESD)
8.2 Functional modes
8.2.1 Control modes
The two control modes of the TFA9812 are I2C and legacy.
• In I2C mode the I2C format control is enabled.
• In Legacy mode a pin-based subset of the control options is available. The control
settings for features which are not available in Legacy mode are set to the default I2C
register settings.
The control mode is selected via pin CSEL as shown in Table 4.
Table 4.
Control mode selection
CSEL Pin value
Control mode
0
Legacy (no I2C)
1
I2C
In the functional descriptions below the control for the various functions will be described
for each control mode. Section 9.6 summarizes the support given by each control mode
for the various TFA9812 functions.
8.2.2 Key operating modes
There are six key operating modes:
• In Sleep mode the voltage supplies are present, but power consumption for the whole
device is reduced to the minimum level. The output stages in Sleep mode are 3-state
and I2C communication is disabled.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
9 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
• In Soft mute mode the I2S input signal is overruled with a soft mute.
– In Legacy control mode the analog input pin AVOL controls Soft mute mode.
– In I2C control mode I2C control can be used to enable an automatic soft mute
function. See also Section 8.5.3.
• In Hard mute mode the PWM controller is overruled with a 50 % duty cycle square
pulse. The Hard mute mode is only available in I2C control mode.
• In Operating mode the TFA9812 amplifies the I2S audio input signal in line with the
actual control setting.
• In 3-state mode the output stages are switched off.
• Fault mode is entered when a fault condition is detected by one or more of the
protection mechanisms implemented in the TFA9812. In Fault mode the actual device
configuration depends on the fault detected: see Section 8.7 for more information.
Fault mode is for a subset of the faults flagged on the DIAG output pin. When the
DIAG pin is flagged the output stages will be forced to enter 3-state mode. In Sleep
mode the DIAG pin will not flag fault modes.
Table 5.
Operational mode selection
Pin:
DIAG Output
Operational mode
selected:
POWERUP ENABLE
CSEL
AVOL
0
-
-
-
floating
Sleep mode
1
-
-
-
0 / floating
Fault mode (enabled by
system)[1]
1
1
1
-
floating
Soft mute mode (in I2C
control mode)[2]
1
1
0
< 0.8 V
floating
Soft mute (in Legacy control
mode)
1
0
-
-
floating
3-state mode
1
1
-
-
floating
Operational mode
[1]
Clocking faults do not trigger DIAG output.
[2]
Under these conditions soft mute still has to be enabled by the appropriate I2C setting.
8.2.3 I2S master/slave modes and MCLK/BCK clock modes
The I2S interface can be set in master or in slave.
• In I2S master mode the PLL locks to the output signal of the internal crystal oscillator
circuit which uses an external crystal. The BCK, WS and MCLK signals are generated
by the TFA9812. On the MCLK pin the TFA9812 delivers a master clock running at the
crystal frequency.
• In I2S slave mode the PLL can lock to:
– The external MCLK signal on the MCLK pin called MCLK clock mode.
– The I2S input BCK signal on the BCK pin called BCK clock mode.
The I2S master or slave mode can be selected:
• In I2C control mode by selecting the right I2C setting.
• In legacy control mode by selecting the right setting on the SDA/MS pin.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
10 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 6.
I2S master/slave mode selection
Pin value
Clock mode
I2S mode
CSEL
SDA/MS
0
0
legacy
slave
0
1
legacy
master
-
I2 C
slave or master[1]
1
[1]
Under these conditions the mode is enabled by the appropriate I2C setting.
In I2S slave mode selection between BCK and MCLK clock modes is automatic.
MCLK clock mode is given higher priority than BCK. If the MCLK clock is judged valid by
the protection circuit then MCLK clock mode is enabled. BCK clock mode is enabled when
the MCLK clock is invalid (e.g. not available) and the BCK clock is judged valid by the
protection circuit (see Section 8.7.11).
Table 7 shows the supported crystal frequencies in I2S master mode.
Table 8 shows the supported MCLK frequencies in MCLK mode (I2S slave mode).
Table 9 shows the supported BCK frequencies in BCK mode (I2S slave mode).
Table 7.
Valid crystal frequencies in I2S master mode
Control mode
fs (kHz)
Crystal frequency (MHz)
I2C
8, 16, 32, 64, 128
8.192
11.025, 22.05, 44.1, 88.2,
176.4
11.2896
12, 24, 48, 96, 192
12.288
32
8.192
44.1
11.2896
48
12.288
Legacy
Table 8.
Valid MCLK frequencies in I2S slave mode
Control mode
fs (kHz)
MLCK frequency (MHz)
I2C
8, 16, 32, 64, 128
8.192
12.288
32
18.432 (576 fs)
11.025, 22.05, 44.1, 88.2,
176.4
11.2896
44.1
25.4016 (576 fs)
12, 24, 48, 96, 192
16.9344
12.288
18.432
48
TFA9812_1
Preliminary data sheet
27.648 (576 fs)
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
11 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 8.
Valid MCLK frequencies in I2S slave mode
Control mode
fs (kHz)
MLCK frequency (MHz)
Legacy
32
8.192
12.288
18.432 (576 fs)
44.1
11.2896
16.9344
25.4016 (576 fs)
48
12.288
18.432
27.648 (576 fs)
Table 9.
Valid BCK frequencies in I2S slave mode
Control mode
I2C
Legacy
[1]
fs (kHz)
8 to
32 fs
8 to
192[1]
48 fs
8 to
192[1]
64 fs
32, 44.1, 48
32 fs
32, 44.1, 48
48 fs
32, 44.1, 48
64 fs
The valid sample frequencies are shown in Section 9.5.7.
TFA9812_1
Preliminary data sheet
BCK (x fs input)
192[1]
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
12 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
8.3 Power-up/power-down
external
voltage
supplies
POWERUP
pin
ENABLE
pin
I2C
available
soft mute
setting in
I2C mode
AVOL pin
in Legacy
mode
PWM
outputs
Operating
mode active
twake
td(on)
td(mute_off)
td(soft_mute)
010aaa219
Fig 3.
Power-up/power-down timing
8.3.1 Power-up
Figure 3 and Table 10 describe the power-up timing while Table 11 shows the pin control
for initiating a power-up reset.
Table 10.
Power-up/power-down timing
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
twake
wake-up
time
I2C control
-
4
-
ms
td(on)
turn-on
delay time
-
70
-
135
ms
td(mute_off)
mute off
delay time
-
-
-
128/fs
s
td(soft_mute)
Soft mute
delay time
I2C control
-
-
128/fs
s
legacy
control[1]
-
15
-
ms
[1]
Mute in Legacy mode is controlled by AVOL pin.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
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TFA9812
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BTL stereo Class-D audio amplifier with I2S input
In I2C control mode communication is enabled after 4 ms. The preferred I2C settings can
be made within 66 ms before the PLL starts running. Finally, the output stages are
enabled and the audio level is increased via a demute sequence if mute has previously
been disabled.
Remark: In I2C mode soft mute is enabled by default. It can be disabled at any time while
I2C communication is valid. In order to prevent audio clicks volume control (default setting
is 0 dB) should be set before soft mute is disabled.
Remark: For a proper start-up in I2S master mode and I2C mode the following sequence
should be followed:
1. The I2S master setting should be set and keep the default sample rate setting active.
2. Next, another sample rate setting than the default one should be selected.
3. Finally, when the default sample rate is used the default sample rate setting should be
selected again.
8.3.2 Power-down
Figure 3 includes the power-down timing while Table 11 shows the pin control for enabling
power-down.
Table 11.
Power-up/power-down selection
Power-up pin
value
Description
0
Power-down (Sleep mode)
1
Power-up
Putting the TFA9812 into power-down is equivalent to enabling Sleep mode
(see Section 8.2.2). This mode is entered immediately and no additional clock cycles are
required.
In order to prevent audible clicks, soft mute should be enabled at least Td(soft_mute)
seconds before enabling Sleep mode.
The specified low current and power conditions in Table 1 are valid within 10 µs after
enabling Sleep mode.
8.4 Digital audio data input
8.4.1 Digital audio data format support
The TFA9812 supports a commonly used range of I2S and I2S-like digital audio data input
formats. These are listed in Table 12.
Table 12.
Supported digital audio data formats
BCK frequency
Interface format (MSB first)
Supported in I2C
control mode
Supported in Legacy
control mode
32 fs
I2S up to 16-bit data
yes
yes
32 fs
MSB-justified 16-bit data
yes
yes
32 fs
LSB-justified 16-bit data
yes
yes
48 fs
I2S
yes
yes
48 fs
MSB-justified up to 24-bit data yes
yes
up to 24-bit data
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BTL stereo Class-D audio amplifier with I2S input
Table 12.
Supported digital audio data formats
BCK frequency
Interface format (MSB first)
Supported in I2C
control mode
Supported in Legacy
control mode
48 fs
LSB-justified 16-bit data
yes
no
48 fs
LSB-justified 18-bit data
yes
no
48 fs
LSB-justified 20-bit data
yes
no
48 fs
LSB-justified 24-bit data
yes
yes
64 fs
I2S
yes
yes
64 fs
MSB-justified up to 24-bit data yes
yes
64 fs
LSB-justified 16-bit data
yes
no
64 fs
LSB-justified 18-bit data
yes
no
64 fs
LSB-justified 20-bit data
yes
no
64 fs
LSB-justified 24-bit data
yes
no
up to 24-bit data
Remark: Only MSB-first formats are supported.
RIGHT
LEFT
WS
1
2
3
1
2
3
MSB
B2
BCK
MSB
DATA
B2
MSB
I2S-BUS FORMAT
LEFT
WS
1
2
RIGHT
3
1
2
3
BCK
DATA
MSB
B2
LSB
MSB
B2
LSB
MSB
B2
MSB-JUSTIFIED FORMAT
WS
LEFT
RIGHT
16
15
2
1
16
B15 LSB
MSB
15
2
1
BCK
DATA
MSB
B2
B2
B15 LSB
LSB-JUSTIFIED FORMAT 16 BITS
WS
LEFT
RIGHT
18
17
16
15
2
1
18
B17 LSB
MSB
17
16
15
2
1
BCK
DATA
MSB
B2
B3
B4
B2
B3
B4
B17 LSB
LSB-JUSTIFIED FORMAT 18 BITS
WS
LEFT
20
RIGHT
19
18
17
16
15
2
1
20
B19 LSB
MSB
19
18
17
16
15
2
1
BCK
DATA
MSB
B2
B3
B4
B5
B6
B2
B3
B4
B5
B6
B19 LSB
LSB-JUSTIFIED FORMAT 20 BITS
WS
LEFT
24
23
22
21
20
RIGHT
19
18
17
16
15
2
1
24
B23 LSB
MSB
23
22
21
20
19
18
17
16
15
2
1
BCK
DATA
MSB
B2
B3
B4
B5
B6
B7
B8
B9
B10
B2
B3
B4
B5
B6
B7
B8
B9
B10
B23 LSB
010aaa458
LSB-JUSTIFIED FORMAT 24 BITS
Fig 4.
Serial interface input and output formats
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BTL stereo Class-D audio amplifier with I2S input
In I2C control mode the following sample frequency fs can be used: 8 kHz, 11.025 kHz,
12 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, 48 kHz, 64 kHz, 88.2 kHz, 96 kHz,
128 kHz, 176.4 kHz or 192 kHz. The I2C control for fs selection can be found in
Section 9.5.7.
In Legacy control mode the following sample frequencies (fs) can be used: 32 kHz,
44.1 kHz or 48 kHz.
8.4.2 Digital audio data format control
The BCK-to-WS and MCLK-to-WS frequency ratios are automatically detected, so no
control settings need to be configured for these.
In I2C control mode all the formats listed in Table 12 are supported. The appropriate I2C
controls for selecting the supported formats can be found in Section 9. In the Legacy
control mode only a subset of the supported formats can be used. These are shown in
Table 12 and the required pin control is given in Table 13.
See Section 8.2.1 for details of how to enable Legacy control mode.
Table 13.
Digital audio data format selection in Legacy control mode
SCL/SFOR pin value
Interface formats (MSB-first)
0
I2S
1
MSB-justified
8.5 Digital signal-processing features
8.5.1 Equalizer
8.5.1.1
Equalizer options
The equalizer function can be bypassed and the equalizer can be configured to either a
5-band or 10-band function. These settings are for both audio channels simultaneously.
There are 20 bands in the equalizer. These are distributed as follows:
• Bands A1 to A5 are bands 1 to 5 of output 1 (used in 5-band and 10-band
configuration).
• Bands B1 to B5 are bands 1 to 5 of output 2 (used in 5-band and 10-band
configuration).
• Bands C1 to C5 are bands 6 to 10 of output 1 (used in 10-band configuration only).
• Bands D1 to D5 are bands 6 to 10 of output 2 (used in 10-band configuration only).
In I2C control mode each band can be configured separately using I2C register settings.
In Legacy control mode the equalizer is bypassed.
8.5.1.2
Equalizer band function
The shape of each parametric equalizer band is determined by the three filter parameters:
• (Relative) center frequency ω = 2π ( f c ⁄ f s ).
• Quality factor Q.
• Gain factor G.
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BTL stereo Class-D audio amplifier with I2S input
In the above equation fc is the center frequency and fs is the sample frequency.
The definition of the quality factor is the center frequency divided by the 3 dB bandwidth,
see Equation 1. In parametric equalizers this is only valid when the gain is set very small
(−30 dB).
f 1:
Af 
10
20 log  --------1
 A f c
= 3dB f c > f 1
f 2:
Af 
10
20 log  --------2
 A f c
= 3dB , f 2 > f c
fc
Q = -----------------;
f2 – f1
(1)
Each band filter can be programmed to perform a band-suppression (G < 1) or a
band-amplification (G > 1) function around the center frequency.
Each band of the TFA9812 equalizer has a second-order Regalia-Mitra all-pass filter
structure. The structure is shown in Figure 5.
+
½
+
Y(z)
+
X(z)
s
−
K0/2
A(z)
010aaa406
Fig 5.
Regalia filter flow-diagram
The transfer function of this all-pass filter is shown in Equation 2:
H (z) = 1 ⁄ 2 ⋅ (1 + A(z)) + K 0 ⁄ 2 ⋅ (1 – A(z))
(2)
A(z) is the second-order filter structure. The transfer function of A(z) is shown in
Equation 3:
–1
–2
K 1 + K 2 ⋅ (1 + K 1) ⋅ Z + Z
A ( z ) = -------------------------------------------------------------------------------–1
–2
1 + K 2 ⋅ (1 + K 1) ⋅ Z + K 1 ⋅ Z
(3)
The relationship between the programmable parameters K0, K1, and K2 and the filter
parameters G, ω, Q is shown in Equation 4 and Equation 5.
Use Equation 4 to calculate band suppression (G < 1) functions.
K0 = G
K 1 = – cos ω
K 2 = ( 2Q ⋅ G – sin ω ) ⁄ ( 2Q ⋅ G + sin ω )
(4)
G<1
Use Equation 5 to calculate band amplification (G ≥ 1) functions.
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BTL stereo Class-D audio amplifier with I2S input
K0 = G
K 1 = – cos ω
(5)
K 2 = ( 2Q – sin ω ) ⁄ ( 2Q + sin ω )
G≥1
The ranges of the TFA9812 parametric equalizer settings for each band are:
• The Gain, G is from −30 dB to +12 dB.
• The center frequency, fc is from 0.0004 * fs to 0.49 * fs.
• The quality factor Q is from 0.001 to 8.
Using I2C control, filter coefficients need to be entered for each filter stage to configure it
as desired.
Figure 6, Figure 7 and Figure 8 show some of the possible transfer functions of the
equalizer bands. The relations are symmetrical for the suppression and amplification
functions. A skewing effect can be observed for the higher frequencies.
Different configurations are available for the same filter transfer function, thus allowing
optimum numerical noise performance. The binary filter configuration parameters t1 and t2
control the actual configuration and should be chosen according to Equation 6.
0
t 1 = 1

0
t 2 = 1

ω<=π ⁄ 2
ω>π ⁄ 2
k 2 >=0
k 2 <0
(6)
A maximum of 12 dB amplification per equalizer stage can be achieved with respect to the
input signal. Each band of the equalizer is provided with a −6 dB amplification, so in order
to prevent numerical clipping for some filter settings with over 6 dB of amplification, band
filters can be scaled by 0 dB or −6 dB. For optimum numerical noise performance steps of
−6 dB amplification should be applied to the highest possible sections that are still within
scale signal processing safeguards. Band filters can be scaled with the binary parameters
listed in Table 14.
Table 14.
8.5.1.3
Equalizer scale factor coding
s
scale factor (dB)
0
0
1
−6
Equalizer band control
For compact representation with positive signed parameters, parameters k1’ and k2’ are
introduced in Equation 7.
The parameters k0, k1', k2', t1, t2 and s must be combined in two 16-bit control words,
word1 and word2, and must fit within the representation given in Table 15. Parameters k1'
and k2' are unsigned floating-point representations in Equation 8.
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BTL stereo Class-D audio amplifier with I2S input
 1 – k1
k1′ = 
1 + k1
t1 = 1
 1 – k2
k2′ = 
1 + k2
t2 = 0
kx = M ⋅ 2
t1 = 0
(7)
t2 = 1
–E
(8)
M<1
In Equation 8, M is the unsigned mantissa and E the negative signed exponent. For
example, in word2 bits [14:8] = [0111 010] represent k2' = (7/24) × 2−2 = 1.09375 10−1.
Table 15.
Equalizer control word construction
Word
Section
Data
word1
15
t1
word1
[14:4]
11 mantissa bits of k1’
word1
[3:0]
Four exponent bits of k1’
word2
15
t2
word2
[14:11]
Four mantissa bits of k2’
word2
[10:8]
Three exponents bits of k2’
word2
[7:1]
k0
word2
0
s
Section 9.5.4 shows the I2C address locations of the controls for various bands of the
equalizer.
010aaa222
12
Q1 = 0.27
Gain
(dB)
Q2 = 0.61
8
Q3 = 1.65
4
0
101
Fig 6.
102
103
Transfer functions for several quality factors Q
TFA9812_1
Preliminary data sheet
104
105
Frequency (Hz)
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BTL stereo Class-D audio amplifier with I2S input
010aaa223
12
Gain
(dB)
8
4
0
101
102
103
104
105
Frequency (Hz)
Fig 7.
Transfer functions for several center frequencies fc
010aaa224
12
Gain
(dB)
6
0
-6
-12
101
102
103
104
105
Frequency (Hz)
Fig 8.
Transfer functions for several gain factors G
8.5.2 Digital volume control
In I2C control mode both audio channels have separate digital volume control. In Legacy
control mode the volume control of both channels is common and the volume control
setting depends on the supply voltage on the pin AVOL (32).
8-bit volume control is available per channel. This is dB-linear down to −124 dB in steps of
0.5 dB. The last step of the volume control is mute.
Table 16 shows the various settings and their related channel suppression:
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BTL stereo Class-D audio amplifier with I2S input
Table 16.
Volume control channel suppression table
[7:0] control value (hexadecimal)
Gain (dB)
00
0
01
−0.5
...
steps of 0.5 dB
F7
−123.5
F8
−124
F9
mute
Section 9 shows the I2C address locations for the digital gain control for both channels.
In Legacy mode the pin AVOL (32) can be used to control the volume.
Voltage levels of 0.8 V to 2.8 V correspond linearly to control values of 00h (0 dB) to F9h
(mute). See Table 16.
An external pull-up resistor connected to the VDDD(3V3) can be applied to provide a default
volume of 0 dB. Pin AVOL has no function in I2C mode.
8.5.3 Soft mute and mute
Soft mute is available in I2C and in Legacy control modes: hard mute can be enabled only
in I2C control mode.
In I2C control mode the soft mute function smoothly reduces the gain setting for both
channels to mute level over a duration of 128/fs seconds. The smooth shape is
implemented as a raised cosine function. Soft demute results in a similar gain increase.
This implementation avoids audible plops.
A different soft mute and soft demute function is implemented in Legacy mode. This works
via the analog gain control under the control of pin AVOL. The analog volume control input
signal is first-order low-pass filtered with a time constant of 10 ms in the digital domain.
Suddenly switching on or switching off volume by setting the control voltage to
> 2.8 V or < 0.8 V respectively will result in a fading which lasts approximately 15 ms
(switching between 0 V and 3.3 V at AVOL).
In Legacy mode the soft demute function that is part of the automatic power-up sequence
is similar to the I2C mode soft demute function described above. The I2C control for the
soft and hard mute functions can be found In Section 9.
8.5.4 Output signal and word-select polarity control
In I2C control mode the TFA9812 can switch the polarity of the stereo output signal. The
effect is a 180 degree phase shift of both output signals.
The TFA9812 also has the option of switching the polarity of the WS signal. Without
polarity inversion the left audio signal is connected to channel 1 and the right audio signal
is connected to channel 2.
The I2C control for the polarity switch can be found in Section 9.5.1.
8.5.5 Gain boost and clip level control
An additional gain boost of +24 dB can be selected in the TFA9812. In Legacy mode this
feature can be selected with the GAIN pin, see Table 17.
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BTL stereo Class-D audio amplifier with I2S input
Table 17.
GAIN pin functionality
GAIN pin value
Function
0
0 dB gain
1
+24 dB gain
The I2C controls for selecting the +24 dB gain can be found in Section 9.5.6. The GAIN
pin has no function In I2C mode.
The TFA9812 features also specific gain settings which are related to < 0.5 %, 10 %, 20 %
or 30 % clipping at the output of the TFA9812. These clipping values are only valid under
the following conditions:
• The volume control is set to 0 dB.
• The gain boost is set to 0 dB.
• A 0 dBFs I2S input signal is obtained.
The I2C controls for selecting a specific clip level can be found in Section 9.5.6. In Legacy
mode the clip level is set to 10 %.
8.5.6 Output power limiter
Output power can be limited to three discrete levels with respect to the maximum power.
The maximum power output value is determined by the value of the high voltage supply.
Clipping levels (see Section 8.5.5) still apply to the maximum levels of reduced output
voltage swings.
In I2C control mode the same output power limiting levels can be selected, see
Section 9.5.6. In Legacy control mode two pins can be used to select the output power
limit level as shown in Table 18.
Table 18.
Legacy mode output power limiter control
Pin value
Function
ADSEL2/PLIM2
ADSEL1/PLIM1
0
0
Maximum power
0
1
Maximum power − 1.5 dB
1
0
Maximum power − 3.0 dB
1
1
Maximum power − 4.5 dB
8.5.7 PWM control for performance improvement
The PWM switching frequency of the TFA9812 is dependent on:
• The sampling frequency, fs.
• The sampling frequency setting, fs(selected) (see Section 9.5.7).
• The PWM switching frequency setting, fsw (selected) (see Section 9.5.6).
Equation 9 shows the relationship between these settings and the PWM carrier
frequency:
fs
f sw = ---------------------------- ⋅ f sw ( selected )
f s ( selected ) )
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The selected PWM switching frequency is 400 kHz by default and can be set to 350 kHz,
700 kHz and 750 kHz in I2C control mode. In Legacy mode 400 kHz is the only option and
this scales linearly if 32 kHz or 48 kHz is used as fs.
Remark: The selected sample frequency, fs (selected) must be equal to the sample
frequency (fs) in I2C control mode.
Remark: The performance of AM radio reception can sometimes be improved by
selecting non-interfering frequencies for the PWM signal.
8.6 Class-D amplification
The Class-D power amplification of the PWM signal is carried out in two BTL power
stages. The output signal voltage level is determined by the values on the VDDP pins.
The power amplifiers can be explicitly put into 3-state mode by using the pin ENABLE as
shown in Table 19. The ENABLE pin is functional in Legacy mode and in I2C mode.
Table 19.
ENABLE pin functionality
ENABLE pin value
Function
0
Output stages in 3-state mode.
1
Switching enabled [1].
[1]
Can be overruled by a forced 3-state in Sleep or Fault mode.
8.7 Protection mechanisms
The TFA9812 has a wide range of protection mechanisms to facilitate optimal and safe
application. All of these are active in both I2C and Legacy control modes.
The following protections are included in the TFA9812:
•
•
•
•
•
•
•
•
•
•
•
•
Thermal Foldback (TF)
OverTemperature Protection (OTP)
OverCurrent Protection (OCP)
OverVoltage Protection (OVP)
UnderVoltage Protection (UVP)
Window Protection (WP)
Lock Protection (LP)
UnderFrequency Protection (UFP)
OverFrequency Protection (OFP)
Invalid BCK Protection (IBP)
DC-blocking
ESD
The reaction of the device to the different fault conditions differs per protection.
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8.7.1 Thermal foldback
If the junction temperature of the TFA9812 exceeds the programmable Thermal foldback
threshold temperature the gain of the amplifier is decreased gradually to a level where the
combination of dissipation (P) and the thermal resistance from junction to ambient (Rth(j-a))
results in a junction temperature around the threshold temperature.
This means that the device will not completely switch off, but remains operational at lower
output power levels. Especially with music output signals this feature enables high peak
output power while still operating without any external heat sink other than the
printed-circuit board area. If the junction temperature still increases due to external
causes, the OTP switches the amplifier to 3-state mode.
Under I2C control the Thermal foldback threshold temperature value can be lowered
(see Section 9.5.8): In Legacy control mode the default threshold value of 125 °C is fixed.
8.7.2 Overtemperature protection
This is a ‘hard’ protection to prevent heat damage to the TFA9812. The overtemperature
threshold level is the 160 °C junction temperature.
When the threshold temperature is exceeded the output stages are set to 3-state mode.
The temperature is then checked at 1 µs intervals and the output stages will operate
normally again once the temperature has dropped below the threshold level.
OTP is flagged by a low DIAG pin. The TFA9812 temperature is an I2C reading, see
Section 9.5.9.
Under normal conditions thermal foldback prevents the overtemperature protection from
being triggered.
8.7.3 Overcurrent protection
The output current of the power amplifiers is current-limited. When an output stage
exceeds a current of 3 A typical, the output stages are set to 3-state mode and after 1 µs
the stages will start operating normally again. These interruptions are not audible.
OCP is flagged by a low DIAG pin and by a high DIAG I2C status bit, see Section 9.5.10.
I2C settings remain valid.
8.7.4 Overvoltage protection
The supply for the power stages (VDDA, VDDP) is protected against overvoltage. When a
supply voltage exceeds 20 V the device will enter Sleep mode. When the supply voltage
has fallen below 20 V again the power-up sequence is started.
OVP is flagged by a low DIAG pin and by a high DIAG I2C status bit, see Section 9.5.10.
I2C settings remain valid.
8.7.5 Undervoltage protections
The supplies are protected against undervoltage. When this is detected the device will
enter Sleep mode. When the supply voltage has risen to a sufficient level again the
power-up sequence is started.
Table 20 shows the UVP trigger levels for the VDDA and VDDA(3V3) supplies:
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Table 20.
Undervoltage trigger levels
Pin name
UVP level
DIAG pin (protection active)
Min
Max
VDDA
≥7V
<8V
LOW
VDDA(3V3)
≥ 1.6 V
<3V
-
8.7.6 Overdissipation protection
When the output current of the power amplifiers exceeds a current value of 3 A and the
temperature is above 140 °C, overdissipation protection is activated and the device enters
Sleep mode. A restart will be initiated automatically when the two overdissipation
conditions are both changed to ‘false’.
Overdissipation is flagged by a low DIAG pin and by a high DIAG I2C status bit, see
Section 9.5.10.
Under normal conditions thermal foldback prevents overdissipation protection from being
triggered. I2C settings remain valid.
8.7.7 Window protection
Window protection is a feature for protecting the device against shorts from the outputs to
the ground or supply lines. If during power-up one of the outputs is shorted to VSSPx or
VDDP, power-up does not proceed any further. The trigger levels for these conditions are:
• OUTxx > VDDA − 1 V, or
• OUTxx < REFA + 1 V.
The WP alarm is flagged by a low DIAG pin and by a high DIAG I2C status bit, see
Section 9.5.10.
8.7.8 Lock protection
When the selected clock input source (MCLK, BCK or crystal) stops running, the TFA9812
is able to detect this and set the output stages to 3-state mode. Without this protection
peripheral devices in an application might be damaged.
The PLL lock indication is an I2C reading and will be ‘false’ in the event of a clock
interruption, see Section 9.5.10.
8.7.9 Underfrequency protection
UFP sets the output stages to 3-state mode when the clock input source is too low. The
PWM switching frequency can becomes critically low when the clock input source is lower
than specified. Without UFP peripheral devices in an application might be damaged.
The status of the UFP is shown in I2C reading register, see Section 9.5.10.
8.7.10 Overfrequency protection
OFP sets the output stages to 3-state mode when the clock input source is too high. The
PWM controller can become unstable when the clock input source is higher than
specified. Without OFP peripheral devices in an application might be damaged.
The status of the OFP is shown in I2C reading register, see Section 9.5.10.
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8.7.11 Invalid BCK protection
The BCK clock signal is verified as being at one of the allowed relative frequencies: 32 fs,
48 fs or 64 fs. If it is not at one of these frequencies the TFA9812 will set the output stages
to 3-state mode to prevent audible effects.
The MCLK clock signal is also verified as being valid, see Section 8.2.3.
Detection of violation results in an automatic internal overruling of the MCLK assignment
to BCK.
8.7.12 DC blocking
The TFA9812 features a high pass filter after the I2S input to block DC signals. DC values
at the output can damage the peripheral devices. The high pass filter is always enabled.
8.7.13 Overview protections
Table 21 shows the overview of the protections.
Table 21.
Overview protections
Protections
Symbol Conditions
DIAG
pin
I2C
Output
flag[1]
TF
programmable
max. Tj > 125 °C
Floating
-
Switching Automatic, increasing
volume control back to
volume setting
OTP
Tj > 160 °C
LOW
DIAG
Floating
Automatic, after 1 µs and
Tj < 160 °C
OCP
IO > IORM
LOW
DIAG
Floating
Automatic, after 1 µs and
IO < IORM
OVP
VDDA > 20 V
LOW
DIAG
Floating
Restart (fault to operating
when VDDA > 8 V and
VDDA(3V3) > 3 V)
UVP
VDDA < 8 V or
VDDA(3V3) < 3 V
LOW
DIAG
Floating
Restart (fault to operating
when VDDA > 8 V and
VDDA(3V3) > 3 V)
ODP
Tj > 140 °C and IO > IORM
LOW
DIAG
Floating
Restart (fault to operating
when Tj < 140 °C or
IO < IORM)
WP[2]
OUTX > VDDA − 1 V or
OUTX < REFA + 1 V
LOW
DIAG
Floating
Restart (fault to operating
when OUTX < VDDA − 1 V
and OUTX > VSSA + 1 V)
LP
PLL out of lock
Floating
LP
Floating
Restart (fault to operating
when PLL is in lock)
UFP
PLL frequency < 45 MHz
Floating
UFP
Floating
Restart (fault to operating
when
PLL frequency > 45 MHz)
TFA9812_1
Preliminary data sheet
Recovering
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TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 21.
Overview protections …continued
Protections
Symbol Conditions
DIAG
pin
I2C
Output
flag[1]
Recovering
OFP
PLL frequency > 140 MHz Floating
OFP
Floating
Restart (fault to operating
when
PLL frequency < 140 MHz)
IBP
BCK/WS is not 32 ± 2,
48 2 or 64 2
-
Floating
Restart (fault to operating
when BCK/WS is 32 ± 2,
48 2 or 64 2)
Floating
[1]
See, Section 9.5.10.
[2]
Window Protection is only checked at power-up.
9. I2C bus interface and register settings
9.1 I2C bus interface
The TFA9812 supports the 400 kHz I2C bus microcontroller interface mode standard. This
can be used to control the TFA9812 and to exchange data with it when in I2C control
mode, see Section 8.2.1.
The TFA9812 can operate in I2C slave mode only as slave receiver or a slave transmitter.
The serial hardware interface involves the pins of the TFA9812 as described in Table 22.
Table 22.
I2C pins in I2C control mode
Pin name
Description
SCL/MUTE
I2C bus clock input
SDA/MS
I2C bus data input and output
ADSEL2/PLIM2
I2C bus device address bit A2
ADSEL1/PLIM1
I2C bus device address bit A1
Voltage values applied to the I2C bus device address pins are interpreted as described in
Table 23.
Table 23.
I2C pin voltages in I2C control mode
Logic value
Voltage A2/A1
0
< VIL
1
> VIH
9.2 I2C bus TFA9812 device addresses
Table 24 shows the register address options for the TFA9812 as part of the 8-bit byte that
contains the device address as well as the bit indicator read/write_not R/!W. The TFA9812
supports four different addresses, each of which can be configured using the pins
ADSEL1/PLIM1 and ADSEL2/PLIM2, see Table 22.
Table 24.
I2C bus device address
(MSB)
Bit
1
1
(LSB)
0
1
TFA9812_1
Preliminary data sheet
0
A2
A1
R/!W
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TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
9.3 I2C write cycle description
Table 25 shows the cycle required for writing data to the I2C registers of the TFA9812. The
byte size is 8 bits. The I2C registers of the TFA9812 store two data bytes. Data is always
written in pairs of two bytes. Data transfer is always MSB first.
The cycle format for writing to the TFA9812 using SDA is as follows:
1. The microcontroller asserts a start condition (S).
2. The microcontroller sends the device address (7 bits) of the TFA9812 followed by the
R/!W bit set to 0.
3. The TFA9812 asserts an acknowledge (A).
4. The microcontroller writes the 8-bit TFA9812 register address to which the first data
byte will be written.
5. The TFA9812 asserts an acknowledge.
6. The microcontroller sends the first byte. This is the most significant byte of the
register.
7. The TFA9812 asserts an acknowledge.
8. The microcontroller sends the second byte.
9. The TFA9812 asserts an acknowledgement.
10. The microcontroller can either assert the stop condition (P) or continue with a further
pair of data bytes, repeating step 6. In the latter case the targeted register address will
have been auto-increased by the TFA9812.
Table 25.
I2C write cycle
Start
TFA9812
Address
R/!W
S
11010A2A1
0
TFA9812 first
register address
A
ADDR
MS
databyte
A
MS1
A
LS
databyte
More Stop
data...
LS1
<....>
P
9.4 I2C read cycle description
Table 26 shows the cycle required for reading data from the I2C registers of the TFA9812.
The byte size is 8 bits. The I2C registers of the TFA9812 store two data bytes. Data is
always read in pairs of two bytes. Data transfer is always MSB-first.
The read cycle format for writing to the TFA9812 using SDA is as follows:
1. The microcontroller asserts a start condition (S).
2. The microcontroller sends the device address (7 bits) of the TFA9812 followed by the
R/!W bit set to 0.
3. The TFA9812 asserts an acknowledge (A).
4. The microcontroller writes the 8-bit TFA9812 register address from which the first data
byte will be read.
5. The TFA9812 asserts an acknowledge.
6. The microcontroller asserts a repeated start (Sr).
7. The microcontroller resends the device address (7 bits) of the TFA9812 followed by
the R/!W bit set to 1.
8. The TFA9812 asserts an acknowledge.
TFA9812_1
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TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
9. The TFA9812 sends the first byte. This is the most significant byte of the register.
10. The microcontroller asserts an acknowledge.
11. The TFA9812 sends the second byte.
12. The microcontroller asserts either an acknowledge or a negative acknowledge (NA).
– If the microcontroller has asserted an acknowledge, the targeted register address
is auto-increased by the TFA9812 and steps 9 to 12 are repeated.
– If the microcontroller has asserted a negative acknowledge, the TFA9812 frees the
I2C bus and the microcontroller generates a stop condition (P).
Table 26.
I2C read cycle
Start TFA9812
address
S
R/!W
11010A2A1 0
First
register
address
A
ADDR
TFA9812
address
A
Sr
R/!W
11010A2A1 1
MS
data
byte
A
MS1
LS More More
data data... data...
byte
A
LS1 <A>
<....>
Stop
NA
P
9.5 Top-level register map
Table 27 describes the assignments of the various register addresses to the functional
control or status areas at top level. There are 47 control registers and 2 status registers.
The following subsections give the individual register interpretations and bit level details.
Table 27.
Top-level register map
Register Default (hex)
address
(hex)
Access
See:
Description
0x00
R/W
Section 9.5.1
Interpolator settings and soft mute
0x0020;
Legacy_mode
0x0021; I2C_mode
0x01
0x0000
R/W
Section 9.5.2
Volume control
0x02
0x0006
R/W
Section 9.5.3
Format digital in
0x03
0x0002
R/W
Section 9.5.4
Equalizer configuration
0x04
0x0058
R/W
Section 9.5.5
Equalizer_A1 word_1; word_1 for
equalizer band A1, see Section 8.5.1.2
0x05
0x4F40
R/W
Section 9.5.5
Equalizer_A1 word_2; see
Section 8.5.1.2
0x06
0x0058
R/W
Section 9.5.5
Equalizer_B1 word_1
0x07
0x4F40
R/W
Section 9.5.5
Equalizer_B1 word_2
0x08
0x0A63
R/W
Section 9.5.5
Equalizer_C1 word_1
0x09
0x4240
R/W
Section 9.5.5
Equalizer_C1 word_2
0x0A
0x0A63
R/W
Section 9.5.5
Equalizer_D1 word_1
0x0B
0x4240
R/W
Section 9.5.5
Equalizer_D1 word_2
0x0C
0x00B7
R/W
Section 9.5.5
Equalizer_A2 word_1
0x0D
0x4E40
R/W
Section 9.5.5
Equalizer_A2 word_2
0x0E
0x00B7
R/W
Section 9.5.5
Equalizer_B2 word_1
0x0F
0x4E40
R/W
Section 9.5.5
Equalizer_B2 word_2
0x10
0x14A2
R/W
Section 9.5.5
Equalizer_C2 word_1
TFA9812_1
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29 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 27.
Top-level register map …continued
Register Default (hex)
address
(hex)
Access
See:
Description
0x11
0x7A40
R/W
Section 9.5.5
Equalizer_C2 word_2
0x12
0x14A2
R/W
Section 9.5.5
Equalizer_D2 word_1
0x13
0x7A40
R/W
Section 9.5.5
Equalizer_D2 word_2
0x14
0x0156
R/W
Section 9.5.5
Equalizer_A3 word_1
0x15
0x4D40
R/W
Section 9.5.5
Equalizer_A3 word_2
0x16
0x0156
R/W
Section 9.5.5
Equalizer_B3 word_1
0x17
0x4D40
R/W
Section 9.5.5
Equalizer_B3 word_2
0x18
0x2871
R/W
Section 9.5.5
Equalizer_C3 word_1
0x19
0x7140
R/W
Section 9.5.5
Equalizer_C3 word_2
0x1A
0x2871
R/W
Section 9.5.5
Equalizer_D3 word_1
0x1B
0x7140
R/W
Section 9.5.5
Equalizer_D3 word_2
0x1C
0x02A5
R/W
Section 9.5.5
Equalizer_A4 word_1
0x1D
0x4C40
R/W
Section 9.5.5
Equalizer_A4 word_2
0x1E
0x02A5
R/W
Section 9.5.5
Equalizer_B4 word_1
0x1F
0x4C40
R/W
Section 9.5.5
Equalizer_B4 word_2
0x20
0x4A80
R/W
Section 9.5.5
Equalizer_C4 word_1
0x21
0x5040
R/W
Section 9.5.5
Equalizer_C4 word_2
0x22
0x4A80
R/W
Section 9.5.5
Equalizer_D4 word_1
0x23
0x5040
R/W
Section 9.5.5
Equalizer_D4 word_2
0x24
0x0534
R/W
Section 9.5.5
Equalizer_A5 word_1
0x25
0x4B40
R/W
Section 9.5.5
Equalizer_A5 word_2
0x26
0x0534
R/W
Section 9.5.5
Equalizer_B5 word_1
0x27
0x4B40
R/W
Section 9.5.5
Equalizer_B5 word_2
0x28
0xD961
R/W
Section 9.5.5
Equalizer_C5 word_1
0x29
0x4840
R/W
Section 9.5.5
Equalizer_C5 word_2
0x2A
0xD961
R/W
Section 9.5.5
Equalizer_D5 word_1
0x2B
0x4840
R/W
Section 9.5.5
Equalizer_D5 word_2
0x2C
0x0005
R/W
Section 9.5.6
PWM signal control
0x2D
0x000E
R/W
Section 9.5.7
Digital-in clock configuration
0x2E
0x0000
R/W
Section 9.5.8
Thermal foldback control
0x2F
-
R
Section 9.5.9
TFA9812 temperature
0x30
-
R
Section 9.5.10
Miscellaneous status
Reserved registers or bits will be indicated by RSD.
TFA9812_1
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Rev. 01 — 30 October 2008
30 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
9.5.1 Interpolator settings and soft mute
Table 28.
Bit
Register address 00h: miscellaneous I2C interpolator settings
15
14
13
12
11
10
9
8
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
INV_POL
ROFF1
ROFF0
FDEMP2
FDEMP1
FDEMP0
S_MUTE
Default
0
0
1
0
0
0
0
1/0
Symbol
Table 29.
Bit description of register 00h: miscellaneous I2C interpolator settings
Bit
Symbol
Description
6
INV_POL
Enable polarity inversion:
0 = No polarity inversion (left audio signal connected to
channel 1; right signal to channel 2)
1 = Polarity inversion enabled
5 to 4
ROFF[1:0]
Filter roll-off sharpness:
0 = Slow filter roll-off (2 to 8 fs) ≥ stop band > 0.7619 fs
1 = Slow filter roll-off (2 to 8 fs) ≥ stop band > 0.7619 fs
2 = Fast filter roll-off (2 to 8 fs) ≥ stop band > 0.6094 fs
3 = Fast filter roll-off (2 to 8 fs) ≥ stop band > 0.6094 fs
3 to 1
FDEMP[2:0]
Digital de-emphasis setting:
0 = No digital de-emphasis
1 = Digital de-emphasis for fs = 32 kHz
2 = Digital de-emphasis for fs = 44.1 kHz
3 = Digital de-emphasis for fs = 48 kHz
4 = Digital de-emphasis for fs = 96 kHz
5 to 8 = No digital de-emphasis
0
S_MUTE
Soft mute:
0 = Soft mute disabled using raised cosine (default in
Legacy control mode)
1 = Soft mute enabled using raised cosine (default in
I2C control mode)
9.5.2 Volume control
Table 30.
Bit
Register address 01h: volume control
15
14
13
12
11
10
9
8
Symbol
VOL_L7
VOL_L6
VOL_L5
VOL_L4
VOL_L3
VOL_L2
VOL_L1
VOL_L0
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
VOL_R7
VOL_R6
VOL_R5
VOL_R4
VOL_R3
VOL_R2
VOL_R1
VOL_R0
Default
0
0
0
0
0
0
0
0
TFA9812_1
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31 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 31.
Bit description of register 00h: miscellaneous I2C interpolator settings
Bit
Symbol
Description
15 to 8
VOL_L[15:8]
See Table 16 for suppression levels on left channel as
function of data byte setting.
7 to 0
VOL_R[7:0]
See Table 16 for suppression levels on right channel as
function of data byte setting.
9.5.3 Digital input format
Table 32.
Bit
Register address 02h: digital input format
15
14
13
12
11
10
9
8
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
RSD
RSD
RSD
DI_FOR2
DI_FOR1
DI_FOR0
WS_POL
Default
0
0
0
0
0
1
1
0
Table 33.
Bit description of register 02h: digital input format
Bit
Symbol
Description
3 to 1
DI_FOR[2:0]
Digital audio input format:
0 = RSD
1 = RSD
2 = MSB-justified data up to 24 bits
3 = I2S data up to 24 bits
4 = LSB-justified 16-bit data
5 = LSB-justified 18-bit data
6 = LSB-justified 20-bit data
7 = LSB-justified 24-bit data
0
WS_POL
Enable WS signal polarity inversion:
0 = No WS signal polarity inversion
1 = WS signal polarity inversion enabled
9.5.4 Equalizer configuration
Table 34.
Bit
Register address 03h: equalizer configuration
15
14
13
12
11
10
9
8
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
EQ_BP
EQ_BND
Default
0
0
0
0
0
0
1
0
TFA9812_1
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Rev. 01 — 30 October 2008
32 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 35.
Bit description of register 03h: equalizer configuration
Bit
Symbol
Description
1
EQ_BP
Equalizer bypass enable:
0 = Equalizer not bypassed
1 = Equalizer bypassed
0
EQ_BND
Equalizer 10-band or 5-band configuration selection:
0 = 10-band equalizer configuration enabled
1 = 5-band equalizer configuration enabled
9.5.5 Equalizer settings
Table 36. Register addresses xxh = 04, 06...2A
For word1 for equalizer 'yy' see Figure 9
Bit
15
14
13
12
11
10
9
8
Eyy_t1
Eyy_k1m10
Eyy_k1m9
Eyy_k1m8
Eyy_k1m7
Eyy_k1m6
Eyy_k1m5
Eyy_k1m4
Default[1]
-
-
-
-
-
-
-
-
Bit
7
6
5
4
3
2
1
0
Symbol
Eyy_k1m3
Eyy_k1m2
Eyy_k1m1
Eyy_k1m0
Eyy_k1e3
Eyy_k1e2
Eyy_k1e1
Eyy_k1e0
Default[1]
-
-
-
-
-
-
-
-
Symbol
[1]
Default settings are shown in Table 27. The corresponding equalizer configuration is shown in Table 40.
Table 37. Register addresses xxh = 05, 07...2B
For word2 for equalizer 'yy' see Figure 9
Bit
Symbol
15
14
13
12
11
10
9
8
Eyy_t2
Eyy_k2m3
Eyy_k2m2
Eyy_k2m1
Eyy_k2m0
Eyy_k2e2
Eyy_k2e1
Eyy_k2e0
Default
-
-
-
-
-
-
-
-
Bit
7
6
5
4
3
2
1
0
Symbol
Eyy_k06
Eyy_k05
Eyy_k04
Eyy_k03
Eyy_k02
Eyy_k01
Eyy_k00
Eyy_s
Default
-
-
-
-
-
-
-
-
[1]
Default settings are shown in Table 27. The corresponding equalizer configuration is shown in Table 40.
TFA9812_1
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Rev. 01 — 30 October 2008
33 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
A1
Left in
A2
A3
A4
A5
Left out
C1
C2
C3
C4
C5
2 × 5 or 2 × 10
B1
Right in
B2
B3
B4
B5
Right out
D1
D2
D3
D4
D5
2 × 5 or 2 × 10
010aaa404
Fig 9.
Equalizer configuration and register location mapping
Table 38.
Bit description of registers xxh = 04, 06...2A
Bit
Symbol
Description
15
Eyy_t1
The filter configuration bit t1, see Section 8.5.1.2.
14 to 4
Eyy_k1m[10:0]
The 11 mantissa bits of the filter parameter k1, see
Section 8.5.1.2.
3 to 0
Eyy_k1e[3:0]
The four exponent bits of the filter parameter k1, see
Section 8.5.1.2.
Table 39.
Bit
Bit description of registers xxh = 05, 07...2B
Symbol
Description
15
Eyy_t2
The filter configuration bit t2, see Section 8.5.1.2.
14 to 11
Eyy_k2m[3:0]
The four mantissa bits of the filter parameter k2, see
Section 8.5.1.2.
10 to 8
Eyy_k2e[2:0]
The three exponent bits of the filter parameter k2, see
Section 8.5.1.2.
7 to 1
Eyy_k0[6:0]
The seven bits of the filter gain parameter k0, see
Section 8.5.1.2.
0
Eyy_s
The filter scale-factor bits, see Section 8.5.1.2:
0 = No scaling applied
1 = −6 dB amplification enabled
TFA9812_1
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Rev. 01 — 30 October 2008
34 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 40.
Default configuration equalizer for fs = 44.1 kHz
Band
A1/B1
A2/B2
A3/B3
A4/B4
A5/B5
C1/D1
C2/D2
C3/D3
C4/D4
C5/D5
Frequency
(Hz)
31
63
125
250
500
1000
2000
4000
8000
16000
Q-factor
1
1
1
1
1
1
1
1
1
1
Gain (dB)
0
0
0
0
0
0
0
0
0
0
9.5.6 PWM signal control
Table 41.
Bit
Register 2Ch: PWM signal control
15
14
13
12
11
10
9
8
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
PLIM1
PLIM0
PW_OFF
PW_SF1
PW_SF0
PW_CL1
PW_CL0
Default
0
0
0
0
0
1
0
1
Table 42.
Bit description address 2Ch
Bit
Symbol
Description
7
GAIN
+24 dB gain boost:
0 = Gain boost 0 dB
1 = Gain boost +24 dB
6 to 5
PLIM[1:0]
Output power limitation:
0 = Maximum power
1 = Maximum power − 1.5 dB
2 = Maximum power − 3.0 dB
3 = Maximum power − 4.5 dB
4
PW_OFF
Hard mute control:
0 = No hard mute
1 = Hard mute enabled, implemented by PWM signal
with 50 % duty cycle
3 to 2
PW_SF[1:0]
PWM switching frequency:
0 = 350 kHz
1 = 400 kHz
2 = 700 kHz
3 = 750 kHz
1 to 0
PW_CL[1:0]
PWM clip level:
0 = < 0.5 % THD
1 = 10 % THD
2 = 20 % THD
3 = 30 % THD
TFA9812_1
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Rev. 01 — 30 October 2008
35 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
9.5.7 Digital-in clock configuration
Table 43.
Bit
Register 2Dh: digital-in clock configuration
15
14
13
12
11
10
9
8
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
RSD
RSD
FSUB3
FSUB2
FSUB1
FSUB0
DI_MS
Default
0
0
0
0
1
1
1
0
Symbol
Table 44.
Bit description of register 2Dh:digital-in clock configuration
Bit
Symbol
Description
4 to 1
FSUB[3:0]
Sample frequency fs of digital-in signal:
0 = 8 kHz
1 = 11.025 kHz
2 = 12 kHz
3 = 16 kHz
4 = 22.05 kHz
5 = 24 kHz
6 = 32 kHz
7 = 44.1 kHz
8 = 48 kHz
9 = 64 kHz
10 = 88.2 kHz
11 = 96 kHz
12 = 128 kHz
13 = 176.4 kHz
14 = 192 kHz
15 = RSD
0
DI_MS
TFA9812 digital-in Master/Slave mode selection:
0 = Slave mode
1 = Master mode
9.5.8 Thermal foldback control
Table 45.
Bit
Register 2Eh: thermal foldback control
15
14
13
12
11
10
9
8
RSD
RSD
RSD
RSD
RSD
RSD
TP_THR9
TP_THR8
Default
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Symbol
TP_THR7
TP_THR6
TP_THR5
TP_THR4
TP_THR3
TP_THR2
TP_THR1
TP_THR0
Default
0
0
0
0
0
0
0
0
Symbol
TFA9812_1
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Rev. 01 — 30 October 2008
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TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 46.
Bit description of register 2Dh: digital-in clock configuration
Bit
Symbol
Description
9 to 0
TP_THR[9:0]
Reduction on the maximum temperature of 125 °C.
The reduction can be calculated by:
(TP_THR[9:0]
reduction = INTEGER -----------------------------------in °C
2.4552
9.5.9 TFA9812 temperature
Table 47.
Bit
Register 2Fh: TFA9812 temperature
15
14
13
12
11
10
9
8
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
TEMP9
TEMP8
Default
-
-
-
-
-
-
-
-
Bit
7
6
5
4
3
2
1
0
Symbol
TEMP7
TEMP6
TEMP5
TEMP4
TEMP3
TEMP2
TEMP1
TEMP0
Default
-
-
-
-
-
-
-
-
Table 48.
Bit description of register 2Dh: digital-in clock configuration
Bit
Symbol
Description
9 to 0
TEMP[9:0]
Temperature of the TFA9812, which can be calculated in
°C using: Temp TFA9812 = (1023 − TEMP[9:0]) / 2.4552
9.5.10 Miscellaneous status
Table 49.
Bit
Register 30h: miscellaneous status
15
14
13
12
11
10
9
8
Symbol
RSD
RSD
RSD
RSD
RSD
RSD
RSD
RSD
Default
-
-
-
-
-
-
-
-
Bit
7
6
5
4
3
2
1
0
Symbol
RSD
OFP
UFP
UVP1V8
UVP3V3
DIAG
LP
MUTE
Default
-
-
-
-
-
-
-
-
Table 50.
Bit description of register 30h: miscellaneous status
Bit
Symbol
Description
6
OFP
PLL frequency-over-range indicator:
0 = PLL frequency in supported range
1 = PLL frequency exceeds highest supported
frequency value
5
UFP
PLL frequency underrange indicator:
0 = PLL frequency in supported range
1 = PLL frequency below lowest supported frequency
value
4
UVP1V8
Undervoltage detector for pins 4 and 41:
0 = No UVP has been detected
1 = A UVP has been detected since the last read-out of
the register
TFA9812_1
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Rev. 01 — 30 October 2008
37 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 50.
Bit description of register 30h: miscellaneous status …continued
Bit
Symbol
Description
3
UVP3V3
Undervoltage detector for pins 3 and 40:
0 = No UVP has been detected
1 = A UVP has been detected since the last read-out of
the register
2
DIAG
Diagnostic pin flagging status[1]:
0 = Diagnostic pin has not been flagged low
1 = Diagnostic pin has been flagged low since the last
read-out of the register
1
LP
PLL lock protection indicator:
0 = PLL is in locked status
1 = PLL is not in locked status
0
MUTE
Soft mute status:
0 = No soft-mute or soft mute/demute in progress
1 = Audio signal muted as result of a soft mute
[1]
The diagnostic pin 30 DIAG is flagged when several protection mechanisms have been active, see
Section 8.7.
9.6 Overview of functional control in each control mode
Table 51 shows the control level supported by either I2C or Legacy control mode for all
functions described in Section 9. It summarizes the information provided in the detailed
description of each function.
Table 51. Functional control support in I2C and Legacy control modes
D = fixed control setting, determined by default I2C register setting; N = not supported; Y = fully
supported (i.e. all options implemented in the TFA9812).
Control function
Reference
I2C mode
Legacy mode
I2C
Section 9
Y
N/D
Sleep mode enable
register content
Section 8.2.2
Y
Y
Operating mode enable
Section 8.2.2
Y
Y
3-state mode enable
Section 8.2.2
Y
Y
I2 S
Section 8.2.3
Y
Y
MCLK/BCK master input clock selection
Section 8.2.3
Auto
Auto
Digital audio input format selection
Section 8.4
Y
Subset
Selection fs = 8 kHz to 192 kHz
Section 8.4.1
Y
D[1]
Equalizer enable and configuration
Section 8.5.1
Y
D[2]
Detailed equalizer settings
Section 8.5.1
Y
N
Digital volume control per channel
Section 8.5.2
Y
N
Analog volume control (shared for two channels) Section 8.5.3
N
Y
De-emphasis for subset of allowed fs
Section 8.5.3
Y
N
Soft mute
Section 8.5.3
Y
Y[3]
Hard mute
Section 8.5.3
Y
N
Polarity switch enable
Section 8.5.4
Y
N
+24 dB gain boost
Section 8.5.6
Y
Y
Master/Slave
TFA9812_1
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Rev. 01 — 30 October 2008
38 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 51. Functional control support in I2C and Legacy control modes …continued
D = fixed control setting, determined by default I2C register setting; N = not supported; Y = fully
supported (i.e. all options implemented in the TFA9812).
Control function
Reference
I2C mode
Legacy mode
Clip level control
Section 8.5.5
Y
D[4]
Output power limit level control
Section 8.5.6
Y
Y
PWM signal frequency selection
Section 8.5.7
Y
D[5]
Thermal foldback threshold temperature control Section 8.7.1
Y
N
[1]
32 kHz, 44.1 kHz and 48 kHz supported
[2]
Bypass.
[3]
Special Legacy mode implementation.
[4]
10 % clip level.
[5]
400 kHz.
10. Internal circuitry
Table 52.
Internal circuitry
Pin
Symbol
1
XTALIN
32
AVOL
Equivalent circuitry
1, 32
ESD
VSS1, VSS2, REFA, REFD
Exposed die paddle
010aaa459
2
XTALOUT
STABA
2
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa460
3
VDDA(3V3)
40
VDDD(3V3)
3, 40
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa461
TFA9812_1
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TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 52.
Internal circuitry …continued
Pin
Symbol
4
STABA
41
STABD
Equivalent circuitry
VDDA(3V3), VDDD(3V3)
4, 41
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa462
5
REFA
6
VDDA
6
24 V
VSS1, REFD, VSS2,
Exposed die-paddle
5
010aaa463
7
TEST1
VDDA
7
13 kΩ
VSS1
010aaa464
9
STAB2
28
STAB1
VDDA
9, 28
12 V
VSS1
010aaa465
10/11
VSSP2
18/19
VDDP
26/27
VSSP1
18/19
24 V
10/11, 26/27
010aaa466
12
BOOT2N
15
BOOT1P
22
BOOT2P
25
BOOT1N
12, 15, 22, 25
12 V
OUT2N, OUT1P, OUT2P, OUT1N
010aaa467
TFA9812_1
Preliminary data sheet
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Rev. 01 — 30 October 2008
40 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 52.
Internal circuitry …continued
Pin
Symbol
13/14
OUT2N
16/17
OUT1P
20/21
OUT2P
23/24
OUT1N
Equivalent circuitry
VDDP
13/14, 16/17, 20/21, 23/24
VSSP1, VSSP2
010aaa468
29
DIAG
VDDA
29
VSS1
VSS1
010aaa469
30
CDELAY
VDDA
2 µA
30
200 nA
5 kΩ
DISCHARGE
VSS1
010aaa470
31
POWERUP
VDDA
3 kΩ
31
250 nA
VSS1
010aaa471
33
ENABLE
34
GAIN
35
CSEL
36
ADSEL2/PLIM2
37
ADSEL1/PLIM1
43
TEST2
33, 34, 35, 36, 37, 43
TFA9812_1
Preliminary data sheet
Pull-down
50 µA
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa472
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
41 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 52.
Internal circuitry …continued
Pin
Symbol
38
SCL/SFOR
Equivalent circuitry
38, 44
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa473
39
SDA/MS
39
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa474
45
WS
46
BCK
47
MCLK
VDDD(3V3)
45, 46, 47
ESD
VSS1, VSS2, REFA, REFD,
Exposed die-paddle
010aaa475
11. Limiting values
Table 53. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
Conditions
Min
Max
Unit
[1]
VDDA
analog supply voltage
−VSS
−0.3
+24
V
VDDP
power supply voltage
−VSSPx; x = 1.2
VDDA(3V3)
analog supply voltage (3.3 V)
−0.3
+24
V
−VSS
[1]
−0.3
+4.6
V
VDDD(3V3)
digital supply voltage (3.3 V)
−VSS
[1]
−0.3
+4.6
V
Tj
junction temperature
-
150
°C
Tstg
storage temperature
−55
+150
°C
Tamb
ambient temperature
−40
+85
°C
P
power dissipation
5
W
TFA9812_1
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© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
42 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 53. Limiting values …continued
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Vx
Parameter
Conditions
voltage on pin x
Vesd
electrostatic discharge voltage
Min
Max
Unit
DIAG
[1]
VSS − 0.3
VSS + 12
V
POWERUP
[1]
VSS − 0.3
VDDA + 0.3
V
ENABLE, GAIN, CSEL,
ADSEL2/PLIM2,
ADSEL2/PLIM1, SCL/SFOR,
SDA/MS, DATA, WS, BCK,
MCLK
[1]
VSS − 0.5
VSS + 5.5
V
AVOL
[1]
VSS − 0.5
VSS + 4.6
V
according to the human body model
STAB1 and STAB2 with
respect to other pins
−1750
+1750
V
all other pins
−2
+2
kV
−500
+500
V
according to the charge
device model
[1]
Vss = VSS1 = VSS2 = REFA = REFD
12. Thermal characteristics
Table 54.
Thermal Characteristics
Symbol
Parameter
Rth(j-a)
Condition
thermal resistance
from junction to
ambient
Rth(j-c)
thermal resistance
from junction to case
Rth(j-lead)
thermal resistance
from junction to lead
Min Typ
Max Unit
[1][2]
-
-
42
K/W
No air flow; typical 4L board in
the NXP 4L reference
application
[2]
-
-
36
K/W
No air flow; typical 2L board in
the NXP 2L reference
application
[2]
-
-
42
K/W
5
-
-
K/W
5
-
-
K/W
No air flow, JEDEC board
[3]
Worst-case pin
[1]
Measured in a JEDEC high K-factor test board (standard EIA/JESD 51-7).
[2]
Measured in free air with natural convection.
[3]
Strongly depends on where measurement is made on the case: worst-case value stated.
TFA9812_1
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Rev. 01 — 30 October 2008
43 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
13. Characteristics
13.1 DC Characteristics
Table 55. DC characteristics
Unless specified otherwise, VDDA = VDDP = 12 V, VSSP1 = VSSP2 = 0 V, VDDA(3V3) = VDDD(3V3) = 3.3 V,
VSS1 = VSS2 = REFD = REFA = 0 V, Tamb = 25 °C, RL = 8 Ω, fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz, 24-bit I2S input data,
MCLK clock mode, typical application diagram (Figure 13).
Symbol
Parameter
Condition
Min
Typ
Max
Unit
Supply voltage
VDDA
analog supply
voltage
8
12
20
V
VDDP
power supply voltage
8
12
20
V
VDDA(3V3)
analog supply
voltage (3.3 V)
3.0
3.3
3.6
V
VDDD(3V3)
digital supply voltage
(3.3 V)
3.0
3.3
3.6
V
IP
supply current
IDDA(3V3)
analog supply
current (3.3 V)
soft mute mode, with
load, filter and snubbers
connected
[1]
-
38
45
mA
sleep mode
[1]
-
160
270
µA
I2S slave mode
-
2
4
mA
I2S
-
4
6
mA
VDDA = VDDP = 12 V
-
120
-
µA
VDDA = VDDP = 1 V
-
40
70
µA
-
15
25
mA
-
25
40
mA
-
4
30
µA
operating mode
master mode
sleep mode
IDDD(3V3)
digital supply current operating mode
(3.3 V)
I2S slave mode
I2S
master mode
sleep mode;
DATA = WS = BCK =
MLCK = 0 V
Amplifier output pins; pins OUT1P, OUT1N, OUT2P and OUT2N
|VO(offset)|
output offset voltage
soft mute mode
-
-
5
mV
Power-up pin
VIH
HIGH-level input
voltage
With respect to VSS1
2.1
-
VDDA
V
VIL
LOW-level input
voltage
With respect to VSS1
−0.3
-
+0.8
V
II
input current
-
0.1
20
µA
MCLK, BCK, WS, DATA pin
VIH
HIGH-level input
voltage
With respect to VSS2
0.7 × VDDD(3V3)
-
-
V
VIL
LOW-level input
voltage
With respect to VSS2
-
-
0.3 × VDDD(3V3)
V
Ci
input capacitance
-
-
3
pF
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
44 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 55. DC characteristics …continued
Unless specified otherwise, VDDA = VDDP = 12 V, VSSP1 = VSSP2 = 0 V, VDDA(3V3) = VDDD(3V3) = 3.3 V,
VSS1 = VSS2 = REFD = REFA = 0 V, Tamb = 25 °C, RL = 8 Ω, fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz, 24-bit I2S input data,
MCLK clock mode, typical application diagram (Figure 13).
Symbol
Parameter
Condition
Min
VOH
HIGH-level output
voltage
At IOH = −0.4 mA
VOL
LOW-level output
voltage
At IOL = 4 mA
CL
load capacitance
Typ
Max
Unit
VDDD(3V3) − 0.4 V -
-
V
-
-
400
mV
-
-
50
pF
SDA/MS, SCL/SFOR pin
VIH
HIGH-level input
voltage
With respect to VSS2
0.7 × VDDD(3V3)
-
5.5
V
VIL
LOW-level input
voltage
With respect to VSS2
−0.3
-
0.3 × VDDD(3V3)
V
Vhys(i)
input hysteresis
voltage
With respect to VSS2
0.1 × VDDD(3V3)
-
-
V
Ci
input capacitance
-
-
2.5
pF
VOL
LOW-level output
voltage
-
-
400
mV
0.7 × VDDD(3V3)
-
-
V
-
0.3 × VDDD(3V3)
V
0.1 × VDDD(3V3)
-
-
V
-
50
93
µA
STAB1 − VSS1
10
11
12
V
STAB2 − VSS1
10
11
12
V
STABA − REFA
1.65
1.8
1.95
V
STABD − REFD
1.65
1.8
1.95
V
voltage on pin
CDELAY
Relative to positive
analog power supply
-
VDDA −1
-
V
peak-to-peak crystal
oscillator output
voltage
With respect to VSS2
-
1.8
-
V
input voltage
Mute level, with respect
to VSS2
0.77
0.8
0.83
V
0 dB level with respect
to VSS2
2.74
2.8
2.86
V
-
-
1
µA
At IOL = 3 mA
ENABLE, GAIN, CSEL, ADSEL2/PLIM2, ASEL1/PLIM1 pin
VIH
HIGH-level input
voltage
With respect to VSS2
VIL
LOW-level input
voltage
With respect to VSS2
Vhys(i)
input hysteresis
voltage
With respect to VSS2
II
input current
Regulators
Vo
output voltage
CDELAY pin
VCDELAY
Crystal pins
Vo(xtal)(p-p)
AVOL pin
Vi
II
input current
TFA9812_1
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Rev. 01 — 30 October 2008
45 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 55. DC characteristics …continued
Unless specified otherwise, VDDA = VDDP = 12 V, VSSP1 = VSSP2 = 0 V, VDDA(3V3) = VDDD(3V3) = 3.3 V,
VSS1 = VSS2 = REFD = REFA = 0 V, Tamb = 25 °C, RL = 8 Ω, fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz, 24-bit I2S input data,
MCLK clock mode, typical application diagram (Figure 13).
Symbol
Parameter
Condition
Min
Typ
Max
Unit
118
125
132
°C
-
-
160
°C
20
22.3
24
V
UVP on VDDA
7
7.5
8
V
UVP on VDDA(3V3)
1.6
2.2
3.0
V
3.0
3.3
3.6
A
high level
-
VDDA − 1
-
V
low level
-
REFA + 1
-
V
Thermal Foldback (TF)
Tact(th_fold)
[2]
thermal foldback
activation
temperature
OverTemperature Protection (OTP)
Tact(th_prot)
thermal protection
activation
temperature
OverVoltage Protection (OVP)
VP(ovp)
overvoltage
protection supply
voltage
UnderVoltage Protections (UVP)
VP(uvp)
undervoltage
protection supply
voltage
OverCurrent Protection (OCP)
IO(ocp)
[3]
overcurrent
protection output
current
Window Protection (WP)
output voltage
Vo
OverFrequency Protection (OFP)
fOFP
Overfrequency
protection frequency
At PLL output frequency
[4]
100
140
185
MHz
At PLL output frequency
[4]
30
45
60
MHz
UnderFrequency Protection (OFP)
Underfrequency
protection frequency
fUFP
[1]
IP is the current through the analog supply voltage (VDDA) pin added to the current through the power supply voltage (VDDP) pin.
[2]
Thermal foldback temperature sensor is not located at hottest spot. Hottest spot is 12 °C higher.
[3]
Current limiting concept: in overcurrent condition no interruption of the audio signal in case of impedance drop.
[4]
PLL output frequency not external available.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
46 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
13.2 AC characteristics
Table 56. AC characteristics
Unless specified otherwise, VDDA = VDDP = 12 V, VDDA(3V3) = VDDD(3V3) = 3.3 V, Tamb = 25 °C, Rs < 0.1 Ω[1], RL = 8 Ω,
fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz, 24-bit I2S input data, MCLK clock mode, typical application diagram (Figure 13).
Symbo Parameter
l
Condition
Min. Typ.
Max. Unit
Output power per channel
Po(RMS)
RMS output power
Continuous time output power per channel; THD = 1 %, RL = 6 Ω
VDDA = VDDP = 12 V
-
7.9
-
W
VDDA = VDDP = 15 V
-
12
-
W
Continuous time output power per channel; THD = 10 %, RL = 6 Ω
VDDA = VDDP = 12 V
-
9.7
-
W
Short time (≤ 10 s) output power per channel; THD = 10 %, RL = 6 Ω
VDDA = VDDP = 15 V
-
15
-
W
Continuous time output power per channel; THD = 1 %, RL = 8 Ω
VDDA = VDDP = 12 V
-
6.6
-
W
VDDA = VDDP = 15 V
-
10
-
W
Continuous time output power per channel; THD = 10 %, RL = 8 Ω
VDDA = VDDP = 12 V
-
8.3
-
W
VDDA = VDDP = 13.5 V
-
10
-
W
VDDA = VDDP = 15 V
-
12
-
W
Short time (≤ 10 s) output power per channel; THD = 10 %, RL = 8 Ω
VDDA = VDDP = 17 V
-
15
-
W
PO = 1 W; AES17 brick wall filter
-
0.07
0.1
%
-
103
-
dB
Performance
THD+N total harmonic distortion-plus-noise
S/N
signal-to-noise ratio
VO = 10 V; A-weighted
Vn(o)
output noise voltage
MCLK clock jitter < 200 ps; AES17 brick-wall filter
operating mode
-
70
-
µV
soft mute mode
-
70
-
µV
hard mute mode
-
30
-
µV
50
54
-
dB
αcs
channel separation
Po(RMS) = 1 W; aggressor channel:
fi = 1 kHz
SVRR
supply voltage ripple rejection
Vripple = 2 Vpp; fripple = 100 Hz
output power efficiency
ηpo
55
60
-
dB
RL = 8 Ω; Po(RMS) = 8.3 W
[2]
-
88
-
%
RL = 6 Ω; Po(RMS) = 9.7 W
[2]
-
83
-
%
-
-
155
ms
Power-up times and delay times
td(on)
turn-on delay time
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
47 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 56. AC characteristics …continued
Unless specified otherwise, VDDA = VDDP = 12 V, VDDA(3V3) = VDDD(3V3) = 3.3 V, Tamb = 25 °C, Rs < 0.1 Ω[1], RL = 8 Ω,
fi = 1 kHz, fs = 44.1 kHz, fsw = 400 kHz, 24-bit I2S input data, MCLK clock mode, typical application diagram (Figure 13).
Symbo Parameter
l
Condition
tPD
fs =
propagation delay
Min. Typ.
Max. Unit
8 kHz
-
3.6
-
ms
11.025 kHz
-
2.58
-
ms
12 kHz
-
2.39
-
ms
16 kHz
-
1.78
-
ms
22.05 kHz
-
1.3
-
ms
24 kHz
-
1.18
-
ms
32 kHz
-
892
-
µs
44.1 kHz
-
664
-
µs
48 kHz
-
600
-
µs
64 kHz
-
458
-
µs
88.2 kHz
-
320
-
µs
96 kHz
-
306
-
µs
128 kHz
-
67.2
-
µs
176.4 kHz
-
48
-
µs
192 kHz
-
40.8
-
µs
PWM output
tr
rise time
IO = 0 A
-
10
-
ns
tf
fall time
IO = 0 A
-
10
-
ns
tw(min)
minimum pulse width
IO = 0 A
-
40
-
ns
RDSon
drain-source on-state resistance
per output MOSFET, for low and high
side
-
0.28
0.35
Ω
δmax
maximum duty factor
-
-
0.96
-
[1]
Rs is the series resistance of inductor of low-pass LC filter in the application.
[2]
Output power measured across the loudspeaker load. This is based on indirect measurement of RDSon.
13.3 Timing
Table 57. Characteristics I2C bus interface; see Figure 10
VDDD(3V3) = VDDA(3V3) = 2.7 V to 3.6 V; VDDA = VDDP = 8 V to 20 V;Tamb = −20 °C to +85 °C; all voltages referenced to ground;
unless otherwise specified.
Symbol
Parameter
fSCL
Min
Typ
Max
Unit
SCL clock frequency
-
-
400
kHz
tLOW
LOW period of the SCL clock
1.3
-
-
µs
tHIGH
HIGH period of the SCL clock
0.6
-
-
µs
SDA and SCL signals
[1]
20 + 0.1 Cb
-
-
ns
SDA and SCL signals
[1]
20 + 0.1 Cb
-
-
ns
[2]
0.6
-
-
µs
tr
tf
tHD;STA
rise time
fall time
Conditions
hold time (repeated) START
condition
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
48 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Table 57. Characteristics I2C bus interface; see Figure 10 …continued
VDDD(3V3) = VDDA(3V3) = 2.7 V to 3.6 V; VDDA = VDDP = 8 V to 20 V;Tamb = −20 °C to +85 °C; all voltages referenced to ground;
unless otherwise specified.
Symbol
Parameter
tSU;STA
Conditions
Min
Typ
Max
Unit
set-up time for a repeated START
condition
0.6
-
-
µs
tSU;STO
set-up time for STOP condition
0.6
-
-
µs
tBUF
bus free time between a STOP and
START condition
1.3
-
-
µs
tSU;DAT
data set-up time
100
-
-
ns
tHD;DAT
data hold time
0
-
-
µs
tSP
pulse width of spikes that must be
suppressed by the input filter
0
-
50
ns
Cb
capacitive load for each bus line
-
-
400
pF
[3]
[1]
Cb is the total capacitance of one bus line in pF. The maximum capacitive load for each bus line is 400 pF.
[2]
After this period, the first clock pulse is generated.
[3]
To be suppressed by the input filter.
SDA
tLOW
tBUF
tr
tf
tHD;STA
tSP
SCL
tHD;STA
P
tHD;DAT
tHIGH
tSU;DAT
S
tSU;STA
Sr
tSU;STO
P
010aaa225
Fig 10. Timing
14. Application information
14.1 Output power estimation
The output power just before clipping can be estimated using Equation 10:
2
RL
  --------------------------------------------------- ⋅δ
⋅V 
  R L + 2 ⋅ ( R DSon + R S ) max P
P O (0.5%) = ---------------------------------------------------------------------------------------------2 ⋅ RL
(10)
Where:
VP = supply voltage (V) (VDDP-VSSP).
RL = load impedance (Ω).
RDSon = ‘On’ resistance power switch (Ω).
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
49 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
RS = Series resistance output inductor (Ω).
δmax = Maximum duty factor (0.96).
The output power at 10 % THD can be estimated using Equation 11:
P O (10%) = 1.25 ⋅ P O (0.5%)
(11)
Figure 11 and Figure 12 show the estimated output power at THD = 0.5 % and
THD = 10 % as a function of BTL supply voltage for different load impedances.
010aaa347
30
010aaa348
45
PO (10 %)
W/channel
PO (0.5 %)
(W/channel)
(1)
(1)
20
30
(2)
(2)
10
15
(3)
(3)
0
0
8
12
16
20
8
24
12
16
20
24
VP (V)
VP (V)
(1) 6 Ω
(1) 6 Ω
(2) 8 Ω
(2) 8 Ω
(3) 16 Ω
(3) 16 Ω
Fig 11. BTL PO (0.5 %) as a function of VP
Fig 12. BTL PO (10 %) as a function of VP
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 12:
VP
I O ( max ) ≤ ----------------------------------------------------R L + 2 ⋅ 〈 R DSon + R S〉
(12)
Where:
VP= supply voltage (V) (VDDP-VSSP)
RL= load impedance (Ω)
RDSon= 'On' resistance power switch (Ω)
RS= series resistance output inductor (Ω)
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
50 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
Remark: A 4.8 Ω speaker (6 Ω speaker with 20 % spread) in BTL configuration can be
used up to a supply voltage of 17 V without running into current limiting. Current limiting
(clipping) will avoid audio holes, but it causes a distortion comparable 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 58.
Filter component values
Impedance (Ω)
LLC (µH)
CLC (nF)
6
15
680
8
18
560
16
47
330
14.4 Typical application schematics
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
51 of 66
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DIAGNOSTIC
NXP Semiconductors
TFA9812_1
Preliminary data sheet
14.4.1 I2S slave mode and Legacy control mode
RVDDA
VPA
10 Ω
POWERUP
DC-VOLUME CONTROL
VP = 8 V to 20 V
POWER IN
VP
ENABLE
CVDDP
220 µF / 25 V
GND
CDELAY
1 nF
25
BOOT1N
STAB1
26
VSSP1
27
VSSP1
28
DIAG
30 29
CDELAY
31
POWERUP
32
AVOL
33
ENABLE
34
24 dB GAIN
ADSEL2/PLIM2
37
CSEL
35
36
CSTAB
100 nF
CBOOT
15 nF
38
39
OUT1N
SCL/SFOR
OUT1N
SDA/MS
BOOT2P
40
VDDD
41
Cvddd
100 nF
CSTABD
1 µF
42
43
I2S DATA
I2S WS
44
45
I2S BCK
46
I2S MLCK (optional)
47
VDDD(3V3)
OUT2P
STABD
OUT2P
VDDP
REFD
TFA9812
TEST2
VDDP
DATA
OUT1P
WS
OUT1P
BCK
BOOT1P
MCLK
OUT2N
VSS2
OUT2N
48
CSN
470 pF
22
21
20
CBOOT
15 nF
CSN
470 pF
F2
Lic
S2
S1
F1
15 µH
OUT1
CLC
680 nF
−
CLC
680 nF
+
6 Ω to 8 Ω
RSN 10 Ω
VP
19
18
CVDDP
100 nF
CVDDP
100 nF
17
16
15
14
CBOOT
15 nF
RSN 10 Ω
F2
CSN
470 pF
CSN
470 pF
Lic
S2
S1
F1
15 µH
CLC
680 nF
+
CLC
680 nF
−
OUT2
RSN 10 Ω
13
3
4
3.3 V
CVDDA
100 nF
5
6
7
8
9
10
11
BOOT2N
VSSP2
VSSP2
STAB2
VSS1
TEST1
VDDA
REFA
STABA
VDDA(3V3)
XTALOUT
2
12
VPA
RSTABA
1 kΩ
CSTAB
100 nF
CVPA
100 nF
CSTAB
100 nF
010aaa476
Fig 13. Simplified application diagram for I2S slave mode and Legacy control mode
6 Ω to 8 Ω
TFA9812
52 of 66
© NXP B.V. 2008. All rights reserved.
1
RSN 10 Ω
23
CBOOT
15 nF
DPAD
XTALIN
49
24
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
ADSEL1/PLIM1
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xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x
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xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
DIAGNOSTIC
NXP Semiconductors
TFA9812_1
Preliminary data sheet
14.4.2 I2S slave mode and I2C control mode
RVDDA
VPA
10 Ω
POWERUP
POWER IN
VP = 8 V to 20 V
ENABLE
VP
CVDDP
220 µF / 25 V
GND
26
VSSP1
27
25
BOOT1N
28
VSSP1
30 29
STAB1
31
AVOL
ENABLE
32
CDELAY
33
POWERUP
34
GAIN
ADSEL2/PLIM2
CSEL
35
36
37
CSTAB
100 nF
CDELAY
1 nF
DIAG
3.3 V
CBOOT
15 nF
OUT1N
I2C SCL
38
I2C SDA
39
40
VDDD
41
CVDDD
100 nF
CSTABD
1 µF
42
43
I2S DATA
44
I2S WS
45
I2S BCK
46
I2S MLCK
47
OUT1N
SCL/SFOR
BOOT2P
SDA/MS
VDDD(3V3)
OUT2P
STABD
OUT2P
VDDP
REFD
TFA9812
VDDP
TEST2
DATA
OUT1P
WS
OUT1P
BOOT1P
BCK
MCLK
OUT2N
VSS2
OUT2N
48
CSN
470 pF
22
21
20
CBOOT
15 nF
CSN
470 pF
F2
Lic
S2
S1
F1
15 µH
OUT1
CLC
680 nF
−
CLC
680 nF
+
6 Ω to 8 Ω
RSN 10 Ω
VP
19
CVDDP
18
100 nF
CVDDP
100 nF
17
16
15
14
CBOOT
15 nF
RSN 10 Ω
F2
CSN
470 pF
CSN
470 pF
Lic
S2
S1
F1
15 µH
CLC
680 nF
CLC
680 nF
OUT2
+
−
RSN 10 Ω
13
3
4
5
3.3 V
CVDDA
100 nF
6
7
8
9
10
11
BOOT2N
VSSP2
VSSP2
STAB2
VSS1
TEST1
VDDA
REFA
STABA
VDDA(3V3)
XTALOUT
2
12
VPA
RSTABA
1 kΩ
CSTAB
100 nF
CVPA
100 nF
CSTAB
100 nF
010aaa477
Fig 14. Simplified application diagram for I2S slave mode and I2C control mode
6 Ω to 8 Ω
TFA9812
53 of 66
© NXP B.V. 2008. All rights reserved.
1
RSN 10 Ω
23
CBOOT
15 nF
DPAD
XTALIN
49
24
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
ADSEL1/PLIM1
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xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
I2S master mode and Legacy control mode
DIAGNOSTIC
NXP Semiconductors
TFA9812_1
Preliminary data sheet
14.4.3
RVDDA
VPA
10 Ω
POWERUP
DC-VOLUME CONTROL
VP = 8 V to 20 V
POWER IN
VP
ENABLE
CVDDP
220 µF / 25 V
GND
CDELAY
1 nF
25
BOOT1N
26
VSSP1
27
VSSP1
CDELAY
28
DIAG
30 29
STAB1
31
POWERUP
32
AVOL
33
ENABLE
CSEL
ADSEL2/PLIM2
37
34
24 dB GAIN
35
36
CSTAB
100 nF
CBOOT
15 nF
38
39
3.3 V
OUT1N
SCL/SFOR
OUT1N
SDA/MS
BOOT2P
40
VDDD
41
Cvddd
100 nF
CSTABD
1 µF
42
43
I2S DATA
I2S WS
44
45
I2S BCK
46
I2S MLCK (optional)
47
VDDD(3V3)
OUT2P
STABD
OUT2P
VDDP
REFD
TFA9812
TEST2
VDDP
DATA
OUT1P
WS
OUT1P
BCK
BOOT1P
MCLK
OUT2N
VSS2
OUT2N
48
XTALL
3
4
CXTALL
18 pF
CVDDA
100 nF
5 6
7 8 9
21
20
CSN
470 pF
CBOOT
15 nF
RSN 10 Ω
F2
Lic
S2
S1
F1
15 µH
OUT1
CLC
680 nF
−
CLC
680 nF
+
10 11
18
CVDDP
100 nF
CVDDP
100 nF
17
16
15
14
CBOOT
15 nF
RSN 10 Ω
F2
CSN
470 pF
CSN
470 pF
Lic
S2
S1
F1
15 µH
CLC
680 nF
+
CLC
680 nF
−
OUT2
RSN 10 Ω
13
12
VPA
RSTABA
1 kΩ
CSTAB
100 nF
CVPA
100 nF
CSTAB
100 nF
010aaa478
Fig 15. Simplified application diagram for I2S master mode and Legacy control mode
6 Ω to 8 Ω
VP
19
BOOT2N
VSSP2
VSSP2
TEST1
VSS1
STAB2
VDDA
REFA
STABA
VDDA(3V3)
XTALOUT
2
3.3 V
CXTALL
18 pF
CSN
470 pF
22
6 Ω to 8 Ω
TFA9812
54 of 66
© NXP B.V. 2008. All rights reserved.
1
RSN 10 Ω
23
CBOOT
15 nF
DPAD
XTALIN
49
24
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
ADSEL1/PLIM1
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx
xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x
xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx
DIAGNOSTIC
NXP Semiconductors
TFA9812_1
Preliminary data sheet
14.4.4 I2S master mode and I2C control mode
RVDDA
VPA
10 Ω
POWERUP
POWER IN
VP = 8 V to 20 V
ENABLE
VP
CVDDP
220 µF / 25 V
GND
CDELAY
1 nF
26
VSSP1
27
STAB1
AVOL
28
25
BOOT1N
30 29
DIAG
31
CDELAY
32
POWERUP
33
ENABLE
CSEL
ADSEL2/PLIM2
37
34
GAIN
35
36
CSTAB
100 nF
VSSP1
3.3 V
CBOOT
15 nF
OUT1N
I2C SCL
38
I2C SDA
39
40
VDDD
41
CVDDD
100 nF
CSTABD
1 µF
42
43
I2S DATA
44
I2S WS
45
I2S BCK
46
I2S MLCK
47
OUT1N
SCL/SFOR
BOOT2P
SDA/MS
VDDD(3V3)
OUT2P
STABD
OUT2P
VDDP
REFD
TFA9812
VDDP
TEST2
DATA
OUT1P
WS
OUT1P
BOOT1P
BCK
MCLK
OUT2N
VSS2
OUT2N
48
CSN
470 pF
22
21
20
CBOOT
15nF
CSN
470 pF
F2
Lic
S2
S1
F1
15 µH
OUT1
CLC
680 nF
−
CLC
680 nF
+
6 Ω to 8 Ω
RSN 10 Ω
VP
19
CVDDP
18
100 nF
CVDDP
100 nF
17
16
15
14
CBOOT
105 nF
RSN 10 Ω
F2
CSN
470 pF
CSN
470 pF
Lic
S2
S1
F1
15 µH
CLC
680 nF
CLC
680 nF
OUT2
+
−
RSN 10 Ω
13
4
CVDDA
100 nF
7
8 9
10 11
BOOT2N
VSSP2
VSSP2
STAB2
VSS1
TEST1
5 6
3.3 V
CXTALL
18 pF
VDDA
REFA
STABA
VDDA(3V3)
XTALOUT
3
12
VPA
RSTABA
1 kΩ
CSTAB
100 nF
CVPA
100 nF
CSTAB
100 nF
010aaa479
Fig 16. Simplified application diagram for I2S master mode and I2C control mode
6 Ω to 8 Ω
TFA9812
55 of 66
© NXP B.V. 2008. All rights reserved.
1 XTALL 2
CXTALL
18 pF
RSN 10 Ω
23
CBOOT
15 nF
DPAD
XTALIN
49
24
BTL stereo Class-D audio amplifier with I2S input
Rev. 01 — 30 October 2008
ADSEL1/PLIM1
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
14.5 Curves measured in typical application
010aaa480
10
010aaa481
10
THD+N
(%)
THD+N
(%)
1
1
(2)
(1)
(1)
10−1
10−1
(3)
(2)
(3)
10−2
10−2
10−1
10
102
Po (W/channel)
1
10−2
10−2
10−1
(1) fi = 6 kHz
(1) fi = 6 kHz
(2) fi = 1 kHz
(2) fi = 1 kHz
(3) fi = 100 Hz
(3) fi = 100 Hz
a. VP = 12 V; RL = 2 × 6 Ω
b. VP = 12 V; RL = 2 × 8 Ω
010aaa482
10
010aaa483
10
THD+N
(%)
THD+N
(%)
1
1
(1)
10
102
Po (W/channel)
1
(2)
(2)
(1)
10−1
10−1
(3)
(3)
10−2
10−2
10−1
1
10
102
Po (W/channel)
10−2
10−2
10−1
(1) fi = 6 kHz
(1) fi = 6 kHz
(2) fi = 1 kHz
(2) fi = 1 kHz
(3) fi = 100 Hz
(3) fi = 100 Hz
c. VP = 15 V; RL = 2 × 6 Ω
1
10
102
Po (W/channel)
d. VP = 15 V; RL = 2 × 8 Ω
Fig 17. Total harmonic distortion-plus-noise as a function of output power
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
56 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
010aaa484
10
THD+N
(%)
THD+N
(%)
1
1
10−1
10−1
10−2
10
102
103
104
105
010aaa485
10
10−2
102
10
103
104
f (Hz)
105
f (Hz)
a. VP = 12 V; RL = 2 × 6 Ω; Po = 1 W
b. VP = 12 V; RL = 2 × 8 Ω; Po = 1 W
Fig 18. Total harmonic distortion-plus-noise as a function of frequency
010aaa486
3
010aaa487
0
G
(dB)
−20
G
(dB)
−40
1
(1)
−60
(2)
(1)
(2)
−1
−80
−100
−3
10
102
103
104
105
−120
0
0.5
1
1.5
2
f (Hz)
VP = 12 V; PO = 1 W
(1) 0 dB
(2) RL = 8 Ω 15 µH / 680 µF
(2) 24 dB gain boost
Fig 20. Gain as a function of AVOL
TFA9812_1
Preliminary data sheet
3
VP = 12 V; RL = 8 Ω; fi = 1 kHz
(1) RL = 6 Ω 15 µH / 680 µF
Fig 19. Gain as a function of frequency
2.5
AVOL (V)
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
57 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
010aaa488
0
SVRR
(dB)
010aaa489
100
S/N
(dB)
−20
(1)
90
(2)
−40
(1)
80
−60
(2)
70
−80
60
−100
102
10
103
104
105
fi (Hz)
VP = 12 V; Vripple = 500 mV (RMS) reference to ground;
No input signal
(1) RL = 8 Ω
50
10−2
10−1
10
102
Po (W/channel)
1
VP = 15 V; 20 kHz AES17 filter
(1) RL = 2 × 8 Ω
(2) RL = 2 × 6 Ω
(2) RL = 6 Ω
Fig 21. SVRR as a function of frequency
Fig 22. S/N ratio as a function of output power
010aaa490
25
010aaa491
25
Po
(W/chan.)
Po
(W/chan.)
20
20
(1)
(1)
15
15
(2)
(2)
10
10
(3)
(3)
5
5
0
0
0
120
240
360
480
600
time (s)
a. VP = 15 V; RL = 2 × 6 Ω BTL; fi = 1 kHz
0
120
240
360
480
600
time (s)
b. VP = 20 V; RL = 2 × 8 Ω BTL; fi = 1 kHz
(1) Tact(th_fold) = 125 °C
(2) Tact(th_fold) = 105 °C
(3) Tact(th_fold) = 90 °C
Fig 23. Output power as a function of time
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
58 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
010aaa492
25
Po
(W/chan.)
010aaa493
25
Po
(W/chan.)
20
(1)
15
(2)
(1)
15
(2)
(3)
(3)
10
20
10
(4)
(4)
5
5
0
0
8
10
12
14
16
18
VP (V)
20
(1) Power limiter = 0 dB
8
10
12
14
16
18
20
VP (V)
(1) Power limiter = 0 dB
(2) Power limiter = −1.5 dB
(2) Power limiter = −1.5 dB
(3) Power limiter = −3 dB
(3) Power limiter = −3 dB
(4) Power limiter = −4.5 dB
(4) Power limiter = −4.5 dB
a. VP = 12 V; RL = 2 × 6 Ω; fi = 1 kHz; THD = 1 %
010aaa494
25
b. VP = 12 V; RL = 2 × 6 Ω; fi = 1 kHz; THD = 10 %
010aaa495
25
Po
(W/chan.)
Po
(W/chan.)
20
20
(1)
15
(2)
(1)
15
(2)
(3)
10
10
(3)
5
(4)
5
(4)
0
0
8
10
12
14
16
18
20
VP (V)
8
10
12
14
(1) Power limiter = 0 dB
(1) Power limiter = 0 dB
(2) Power limiter = −1.5 dB
(2) Power limiter = −1.5 dB
(3) Power limiter = −3 dB
(3) Power limiter = −3 dB
(4) Power limiter = −4.5 dB
(4) Power limiter = −4.5 dB
c. VP = 15 V; RL = 2 × 8 Ω; fi = 1 kHz; THD = 1 %
16
18
20
VP (V)
d. VP = 15 V; RL = 2 × 8 Ω; fi = 1 kHz; THD = 10 %
Fig 24. Output power as a function of supply voltage
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
59 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
010aaa496
3
010aaa497
100
ηPO
(%)
P
(W)
(2)
80
(1)
2
(1)
60
(2)
40
1
20
0
10−2
10−1
1
0
10
102
Po (W/channel)
0
2
4
6
8
10
Po (W/channel)
VP = 12 V; fi = 1 kHz; ηpo = (2 × Po) / (2 × Po + Pd)
VP = 12 V; fi = 1 kHz; Power dissipation in junction only
(1) RL = 2 × 6 Ω
(1) RL = 2 × 6 Ω
(2) RL = 2 × 8 Ω
(2) RL = 2 × 8 Ω
Fig 25. Power dissipation as a function of output
power
Fig 26. Efficiency as a function of output power
010aaa498
0
αcs
(dB)
−20
−40
(1)
−60
(2)
−80
−100
10
102
103
104
105
f (Hz)
VP = 12 V; PO = 1 W
(1) RL = 2 × 6 Ω
(2) RL = 2 × 8 Ω
Fig 27. Channel separation as a function of frequency
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
60 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
15. Package outline
HVQFN48: plastic thermal enhanced very thin quad flat package; no leads;
48 terminals; body 7 x 7 x 0.85 mm
B
D
SOT619-8
A
terminal 1
index area
E
A
A1
c
detail X
e1
e
1/2 e
v
w
b
13
24
L
M
M
C
C A B
C
y1 C
y
25
12
e
e2
Eh
1/2 e
1
36
terminal 1
index area
48
37
X
Dh
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A(1)
max
A1
b
c
D(1)
Dh
E (1)
Eh
e
e1
e2
L
v
w
y
y1
mm
1
0.05
0.00
0.30
0.18
0.2
7.1
6.9
5.75
5.45
7.1
6.9
5.75
5.45
0.5
5.5
5.5
0.5
0.3
0.1
0.05
0.05
0.1
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
JEITA
SOT619-8
---
MO-220
---
EUROPEAN
PROJECTION
ISSUE DATE
07-01-10
07-01-30
Fig 28. Package outline SOT619-8 (HVQFN48)
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
61 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
16. Handling information
It is advisable to abide by the normal precautions appropriate to handling MOS devices.
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
62 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
17. Revision history
Table 59.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
TFA9812_1
20081030
Preliminary data sheet
-
-
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
63 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
18. Legal information
18.1 Data sheet status
Document status[1][2]
Product status[3]
Definition
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
18.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
18.3 Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, NXP Semiconductors does not give any representations or
warranties, expressed or implied, as to the accuracy or completeness of such
information and shall have no liability for the consequences of use of such
information.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Quick reference data — The Quick reference data is an extract of the
product data given in the Limiting values and Characteristics sections of this
document, and as such is not complete, exhaustive or legally binding.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) may cause permanent
damage to the device. Limiting values are stress ratings only and operation of
the device at these or any other conditions above those given in the
Characteristics sections of this document is not implied. Exposure to limiting
values for extended periods may affect device reliability.
Terms and conditions of sale — NXP Semiconductors products are sold
subject to the general terms and conditions of commercial sale, as published
at http://www.nxp.com/profile/terms, including those pertaining to warranty,
intellectual property rights infringement and limitation of liability, unless
explicitly otherwise agreed to in writing by NXP Semiconductors. In case of
any inconsistency or conflict between information in this document and such
terms and conditions, the latter will prevail.
No offer to sell or license — Nothing in this document may be interpreted
or construed as an offer to sell products that is open for acceptance or the
grant, conveyance or implication of any license under any copyrights, patents
or other industrial or intellectual property rights.
18.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
19. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
64 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
20. Contents
1
2
2.1
2.2
2.3
3
4
5
6
7
7.1
8
8.1
8.2
8.2.1
8.2.2
8.2.3
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
General features . . . . . . . . . . . . . . . . . . . . . . . . 1
DSP features . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Audio data input interface format support. . . . . 2
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Quick reference data . . . . . . . . . . . . . . . . . . . . . 3
Ordering information . . . . . . . . . . . . . . . . . . . . . 4
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pinning information . . . . . . . . . . . . . . . . . . . . . . 6
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Functional description . . . . . . . . . . . . . . . . . . . 8
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Functional modes . . . . . . . . . . . . . . . . . . . . . . . 9
Control modes . . . . . . . . . . . . . . . . . . . . . . . . . 9
Key operating modes . . . . . . . . . . . . . . . . . . . . 9
I2S master/slave modes and MCLK/BCK
clock modes . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.3
Power-up/power-down . . . . . . . . . . . . . . . . . . 12
8.3.1
Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.3.2
Power-down . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.4
Digital audio data input . . . . . . . . . . . . . . . . . . 14
8.4.1
Digital audio data format support . . . . . . . . . . 14
8.4.2
Digital audio data format control . . . . . . . . . . . 16
8.5
Digital signal-processing features . . . . . . . . . . 16
8.5.1
Equalizer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.5.1.1
Equalizer options . . . . . . . . . . . . . . . . . . . . . . 16
8.5.1.2
Equalizer band function . . . . . . . . . . . . . . . . . 16
8.5.1.3
Equalizer band control . . . . . . . . . . . . . . . . . . 18
8.5.2
Digital volume control . . . . . . . . . . . . . . . . . . . 20
8.5.3
Soft mute and mute . . . . . . . . . . . . . . . . . . . . 21
8.5.4
Output signal and word-select polarity control 21
8.5.5
Gain boost and clip level control . . . . . . . . . . . 21
8.5.6
Output power limiter . . . . . . . . . . . . . . . . . . . . 22
8.5.7
PWM control for performance improvement . . 22
8.6
Class-D amplification . . . . . . . . . . . . . . . . . . . 23
8.7
Protection mechanisms . . . . . . . . . . . . . . . . . 23
8.7.1
Thermal foldback . . . . . . . . . . . . . . . . . . . . . . 24
8.7.2
Overtemperature protection . . . . . . . . . . . . . . 24
8.7.3
Overcurrent protection . . . . . . . . . . . . . . . . . . 24
8.7.4
Overvoltage protection . . . . . . . . . . . . . . . . . . 24
8.7.5
Undervoltage protections . . . . . . . . . . . . . . . . 24
8.7.6
Overdissipation protection . . . . . . . . . . . . . . . 25
8.7.7
Window protection . . . . . . . . . . . . . . . . . . . . . 25
8.7.8
Lock protection . . . . . . . . . . . . . . . . . . . . . . . . 25
8.7.9
Underfrequency protection . . . . . . . . . . . . . . . 25
8.7.10
Overfrequency protection . . . . . . . . . . . . . . . .
8.7.11
Invalid BCK protection . . . . . . . . . . . . . . . . . .
8.7.12
DC blocking . . . . . . . . . . . . . . . . . . . . . . . . . .
8.7.13
Overview protections . . . . . . . . . . . . . . . . . . .
2
9
I C bus interface and register settings . . . . .
9.1
I2C bus interface. . . . . . . . . . . . . . . . . . . . . . .
9.2
I2C bus TFA9812 device addresses . . . . . . . .
9.3
I2C write cycle description . . . . . . . . . . . . . . .
9.4
I2C read cycle description . . . . . . . . . . . . . . .
9.5
Top-level register map . . . . . . . . . . . . . . . . . .
9.5.1
Interpolator settings and soft mute. . . . . . . . .
9.5.2
Volume control . . . . . . . . . . . . . . . . . . . . . . . .
9.5.3
Digital input format . . . . . . . . . . . . . . . . . . . . .
9.5.4
Equalizer configuration. . . . . . . . . . . . . . . . . .
9.5.5
Equalizer settings . . . . . . . . . . . . . . . . . . . . . .
9.5.6
PWM signal control . . . . . . . . . . . . . . . . . . . .
9.5.7
Digital-in clock configuration. . . . . . . . . . . . . .
9.5.8
Thermal foldback control . . . . . . . . . . . . . . . .
9.5.9
TFA9812 temperature . . . . . . . . . . . . . . . . . .
9.5.10
Miscellaneous status . . . . . . . . . . . . . . . . . . .
9.6
Overview of functional control in each
control mode . . . . . . . . . . . . . . . . . . . . . . . . .
10
Internal circuitry . . . . . . . . . . . . . . . . . . . . . . .
11
Limiting values . . . . . . . . . . . . . . . . . . . . . . . .
12
Thermal characteristics . . . . . . . . . . . . . . . . .
13
Characteristics . . . . . . . . . . . . . . . . . . . . . . . .
13.1
DC Characteristics . . . . . . . . . . . . . . . . . . . . .
13.2
AC characteristics . . . . . . . . . . . . . . . . . . . . .
13.3
Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
Application information . . . . . . . . . . . . . . . . .
14.1
Output power estimation . . . . . . . . . . . . . . . .
14.2
Output current limiting . . . . . . . . . . . . . . . . . .
14.3
Speaker configuration and impedance. . . . . .
14.4
Typical application schematics . . . . . . . . . . . .
14.4.1
I2S slave mode and Legacy control mode . . .
14.4.2
I2S slave mode and I2C control mode . . . . . .
14.4.3
I2S master mode and Legacy control mode .
2
14.4.4
I S master mode and I2C control mode . . . . .
14.5
Curves measured in typical application . . . . .
15
Package outline . . . . . . . . . . . . . . . . . . . . . . . .
16
Handling information . . . . . . . . . . . . . . . . . . .
17
Revision history . . . . . . . . . . . . . . . . . . . . . . .
18
Legal information . . . . . . . . . . . . . . . . . . . . . .
18.1
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
18.2
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
18.3
Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . .
25
26
26
26
27
27
27
28
28
29
31
31
32
32
33
35
36
36
37
37
38
39
42
43
44
44
47
48
49
49
50
51
51
52
53
54
55
56
61
62
63
64
64
64
64
continued >>
TFA9812_1
Preliminary data sheet
© NXP B.V. 2008. All rights reserved.
Rev. 01 — 30 October 2008
65 of 66
TFA9812
NXP Semiconductors
BTL stereo Class-D audio amplifier with I2S input
18.4
19
20
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Contact information. . . . . . . . . . . . . . . . . . . . . 64
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2008.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: [email protected]
Date of release: 30 October 2008
Document identifier: TFA9812_1