The TFA9843AJ contains two identical audio power amplifiers. The TFA9843AJ can be
used as two Single-Ended (SE) channels with a volume control. The maximum gain is
26 dB.
The TFA9843AJcomes in a 9-pin DIL-bent-SIL (DBS9P) power package.The TFA9843AJ
is pin compatible with the TFA9842AJ, TFA9843(B)J, TFA9842(B)J and TFA9841J. The
difference between the TFA9843AJ and the TFA9843(B)J, TFA9842(B)J, TFA9841Jis the
functionality of pin 7. The TFA9843AJ has a volume control on pin 7 (VC). The
TFA9843(B)J, TFA9842(B)J and TFA9841J have a mode select on pin 7 (MODE).
The TFA9843AJ contains a unique protection circuit that is solely based on multiple
temperature measurements inside the chip. This gives maximum output power for all
supply voltages and load conditions with no unnecessary audio holes. Almost any supply
voltage and load impedance combination can be made as long as thermal boundary
conditions (number of channels used, external heatsink and ambient temperature) allow
it.
2.Features
n 2 channel SE: 1 W to 20 W operation possibility
n Soft clipping
n Input clamps
n Volume control
n Standby and Mute mode
n No on or off switching plops
n Low standby current
n High supply voltage ripple rejection
n Outputs short-circuit protected to ground, supply and across the load
n Thermally protected
n Pin compatible with the TFA9842AJ, TFA9843(B)J, TFA9842(B)J, TFA9841J
3.Applications
n CRT TV and LCD TV
n Monitors
n PC speakers
n Boom box
n Mini and micro audio receivers
Philips Semiconductors
4.Quick reference data
Table 1.Quick reference data
VCC =18V; T
unless otherwise specified.
SymbolParameterConditionsMinTypMaxUnit
V
CC
I
q
I
CC(stb)
P
o
THDtotal harmonic
G
v(max)
∆G
v
SVRRsupply voltage ripple
amb
supply voltageoperating
quiescent currentVCC=18V; RL= ∞-60100mA
standby supply current VCC=18V;
output powerTHD = 10 %; RL=4Ω;
distortion
maximum voltage gain V
voltage gain range1.5 V < V
rejection
=25°C; RL=4Ω; V
TFA9843AJ
20 W stereo power amplifier with volume control
I(VC)=VCC
V
I(VC)
V
CC
THD = 10 %; R
V
CC
P
o
I(VC)
f=1kHz
; Vi= 0 V; measured in test circuit of Figure 11;
[1]
9 1828V
--150µA
< 0.8 V
78.5-W
=18V
=4Ω;
L
-14-W
=22V
= 1 W-0.10.5%
> 5.0V252627dB
< 5.0 V-80-dB
I(VC)
[2]
-60-dB
[1] A minimum load of 3 Ω is allowed at supply voltages > 22 V.
[2] Supply voltage ripple rejection is measured at the output, with a source impedance ZS=0Ω at the input
and with a frequency range from 20 Hz to 22 kHz (unweighted). The ripple voltage is a sine wave with a
frequency f
5.Ordering information
Table 2.Ordering information
Type
number
TFA9843AJDBS9Pplastic DIL-bent-SIL power package; 9 leads (lead length
and an amplitude of 300 mV (RMS), which is applied to the positive supply rail.
As shown in Equation 2, large capacitor values for the inputs are not necessary; therefore
switch-on delay during charging of the input capacitors can be minimized. This results in a
good low frequency response and good switch-on behavior.
The TFA9843AJ has clamps on the inputs. In Standby mode the voltage on the input pins
is clamped for voltages lower than −0.1 V. When the TFA9843AJ is in Mute, Volume
control or Operating mode (maximum gain) the input clamp voltage is 1 V (RMS).
8.2 Power amplifier
The power amplifier is a single-ended amplifier with an all NPN output stage, capable of
delivering a peak output current of 4 A.
(1)
(2)
8.2.1 Output power measurement
The output power as a function of the supply voltage is measured on the output pins at
THD=10%;seeFigure 7. The maximum output power is limited by the supply voltage of
26 V and the maximum availableoutput current is 4 A repetitive peak current. A minimum
load of 3 Ω is required for supply voltages > 22 V; see Figure 4. The output power is
measured with one channel driven.
Preliminary data sheetRev. 01 — 28 April 20064 of 19
Philips Semiconductors
8.2.2 Headroom
Typical CD music requires at least 12 dB (factor 15.85) dynamic headroom, compared to
the average power output, for transferring the loudest parts without distortion. At
VCC= 18 V and Po= 6.5 W (SE with RL=4Ω) at THD < 0.5 % (see Figure 5), the
Average Listening Level (ALL) music power without any distortion yields:
TFA9843AJ
20 W stereo power amplifier with volume control
P
oALLSE,()
6.5
-------------
15.85
410 mW==
The power dissipation can be derived from Figure 8 (SE) for 0 dB respectively 12 dB
headroom; see Table 4.
For the average listening level a power dissipation of 4.2 W can be used for a heatsink
calculation.
Table 4.Power rating as function of headroom
HeadroomPower output (THD < 0.5 %)
(SE)
0dBP
12 dBP
= 6.5 W8.2 W
o
= 410 mW4.2 W
o(ALL)
Power dissipation (P);
both channels driven
8.3 Mode selection
The TFA9843AJ has four functional modes, which can be selected by applying the proper
DC voltage to pin VC; see Table 5.
Table 5.Mode selection
V
I(VC)
0 V to 0.8 VStandby
1.2 V to 1.5 VMutein this mode the amplifier is DC-biased but not
1.5 V to 5.0 VVolume controlin this mode the volume of the amplifier can be
5.0 V to V
CC
StatusDefinition
in this mode the current consumption is very low
and the outputs are floating; the device is in
Standby mode when V
I(VC)
< 0.8 V
operational (no audio output); this allows the input
coupling capacitors to be charged to avoid plop
noise; the device is in Mute mode when
1.2V<V
I(VC)
< 1.5 V
controlled; the gain can be adjusted between the
range of 1.5V<V
On (maximum gain)in this mode the amplifier has its maximum gain; the
Operating mode is activated at V
I(VC)
< 5.0 V
I(VC)
> 5.0 V
(3)
8.4 Supply voltage ripple rejection
The supply voltage ripple rejection (SVRR) is measured with an electrolytic capacitor of
150 µF connected to pin SVR with a bandwidth of 20 Hz to 22 kHz. The SVRR as a
function of the frequency is illustrated in Figure 10. A larger capacitor value on pin SVR
improves the ripple rejection behavior at the lower frequencies.
Preliminary data sheetRev. 01 — 28 April 20065 of 19
Philips Semiconductors
8.5 Built-in protection circuits
The TFA9843AJ contains two types of temperature sensors; one measures the local
temperatures of the power stages and one measures the global chip temperature. At a
local temperature of the power stage of approximately 185 °C or a global temperature of
approximately 150 °C this detection circuit switches off the power stages for 2 ms. When
the outputs are switched off the voltage is measured on the outputs. In the event of a
short-circuit to ground or to VCC the device will remain in Protection mode. In all other
cases the power stages switch-on automatically and the detection will take place again;
however a too high temperature will switch-off the power stages immediately. This can
result in repetitive switching during too high junction temperature. This protects the
TFA9843AJ against short-circuits to ground, to the supply voltage, across the load and too
high chip temperatures.
The protection will only be activated when necessary, so even during a short-circuit
condition, a certain amount of (pulsed) current will still flow through the short-circuit (as
much as the power stage can handle without exceeding the critical temperature level).
9.Limiting values
TFA9843AJ
20 W stereo power amplifier with volume control
Table 6.Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
SymbolParameterConditionsMinMaxUnit
V
CC
V
I
I
ORM
T
stg
T
amb
P
tot
V
CC(scp)
supply voltageoperating−0.3+28V
input voltage−0.3VCC+ 0.3V
repetitive peak output current-4A
storage temperaturenon-operating−55+150°C
ambient temperatureoperating−40+85°C
total power dissipation-35W
short-circuit protection supply
Preliminary data sheetRev. 01 — 28 April 200611 of 19
Philips Semiconductors
13.2 Printed-circuit board
13.2.1 Layout and grounding
To obtain a high-level system performance, certain grounding techniques are essential.
The input reference grounds have to be tied with their respective source grounds and
must have separate tracks from the power ground tracks; this will prevent the large output
signal currents from interfering with the small AC input signals. The small-signal ground
tracks should be physically located as far as possible from the power ground tracks.
Supply and output tracks should be as wide as possible for delivering maximum output
power.
Proper supply bypassing is critical for low-noise performance and high supply voltage
ripple rejection. The respective capacitor location should be as close as possible to the
deviceand connected to the power ground. Proper power supply decoupling also prevents
unwanted oscillations.
For suppressing higher frequency transients (spikes) on the supply rail a capacitor with
low ESR (typical 100 nF) has to be placed as close as possible to the device. For
suppressing lower frequency noise and ripple signals, a large electrolytic capacitor (e.g.
1000 µF or greater) must be placed close to the device.
The bypass capacitor connected to pin SVR reduces the noise and ripple on the mid rail
voltage. For good THD and noise performance, a low ESR capacitor is recommended.
Preliminary data sheetRev. 01 — 28 April 200612 of 19
Philips Semiconductors
13.3 Thermal behavior and heatsink calculation
TFA9843AJ
20 W stereo power amplifier with volume control
The measured maximum thermal resistance of the IC package, R
th(j-mb)
, is 2.0 K/W.
A calculation for the heatsink can be made, with the following parameters:
T
amb(max)
=60°C (example)
VCC= 18 V and RL=4Ω (SE)
T
= 150 °C (specification)
j(max)
R
is the total thermal resistance between the junction and the ambient including the
th(tot)
heatsink. This can be calculated using the maximum temperature increase divided by the
power dissipation:
R
th(tot)
=(T
j(max)
− T
amb(max)
)/P
At VCC= 18 V and RL=4Ω (2 × SE) the measured worst case sine wave dissipation is
8.4 W; see Figure 8. For T
= 150 °C the temperature raise, caused by the power
j(max)
dissipation, is: 150 − 60=90°C:
P × R
R
th(tot)
R
th(h-a)=Rth(tot)
=90°C
th(tot)
= 90/8.4 K/W = 10.7 K/W
− R
= 10.7 K/W − 2.0 K/W = 8.7 K/W
th(j-mb)
This calculation is for an application at worst case (stereo) sine wave output signals. In
practice music signals will be applied, which decreases the maximum power dissipation to
approximately half of the sine wave power dissipation; see Section 8.2.2. This allows the
use of a smaller heatsink:
Preliminary data sheetRev. 01 — 28 April 200615 of 19
Philips Semiconductors
16. Soldering
16.1 Introduction to soldering through-hole mount packages
This text gives a brief insight to wave,dip and manual soldering. A more in-depth account
of soldering ICs can be found in our
(document order number 9398 652 90011).
Wave soldering is the preferred method for mounting of through-hole mount IC packages
on a printed-circuit board.
16.2 Soldering by dipping or by solder wave
Driven by legislation and environmental forces the worldwide use of lead-free solder
pastes is increasing. Typical dwell time of the leads in the wave ranges from
3 seconds to 4 seconds at 250 °C or 265 °C, depending on solder material applied, SnPb
or Pb-free respectively.
The total contact time of successive solder waves must not exceed 5 seconds.
TFA9843AJ
20 W stereo power amplifier with volume control
Data Handbook IC26; Integrated Circuit Packages
The device may be mounted up to the seating plane, but the temperature of the plastic
body must not exceed the specified maximum storage temperature (T
printed-circuit board has been pre-heated, forced cooling may be necessary immediately
after soldering to keep the temperature within the permissible limit.
16.3 Manual soldering
Apply the soldering iron (24 V or less) to the lead(s) of the package, either below the
seating plane or not more than 2 mm aboveit. If the temperature of the soldering iron bit is
less than 300 °C it may remain in contact for up to 10 seconds. If the bit temperature is
between 300 °C and 400 °C, contact may be up to 5 seconds.
16.4 Package related soldering information
Table 10. Suitability of through-hole mount IC packages for dipping and wave soldering
Preliminary data sheetRev. 01 — 28 April 200617 of 19
Philips Semiconductors
18. Legal information
18.1Data sheet status
TFA9843AJ
20 W stereo power amplifier with volume control
Document status
Objective [short] data sheetDevelopmentThis document contains data from the objective specification for product development.
Preliminary [short] data sheet QualificationThis document contains data from the preliminary specification.
Product [short] data sheetProductionThis 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 mayhave changedsince this document was publishedand maydiffer incase of multipledevices. Thelatest productstatus
information is available on the Internet at URL
[1][2]
Product status
18.2Definitions
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. Philips Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information includedherein and shall have noliability for theconsequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with thesame product type number(s)and title. Ashort datasheet is intended
for quickreference only and shouldnot be relied upon to containdetailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local Philips Semiconductors
sales office.Incase of any inconsistency orconflict with the short data sheet,
the full data sheet shall prevail.
18.3Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, Philips 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 — Philips 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. Thisdocumentsupersedes and replaces all informationsupplied prior
to the publication hereof.
Suitability for use — Philips 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
[3]
http://www.semiconductors.philips.com.
Definition
malfunction ofaPhilips Semiconductors product canreasonably be expected
to result in personal injury, death or severe property or environmental
damage. Philips Semiconductors accepts no liability for inclusion and/or use
of Philips Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is for the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. Philips Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute MaximumRatings System of IEC 60134)may cause permanent
damage tothedevice. Limiting values are stressratings only and operationof
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 — Philips Semiconductors products are sold
subject to the general terms and conditions ofcommercialsale, as published
at
http://www.semiconductors.philips.com/profile/terms, including those
pertaining to warranty, intellectual property rights infringement and limitation
of liability, unless explicitly otherwise agreed to in writing by Philips
Semiconductors. Incaseof any inconsistency orconflictbetween 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 implicationof any license under any copyrights,patents
or other industrial or intellectual property rights.
18.4Trademarks
Notice: Allreferenced brands,product names, service namesand trademarks
are the property of their respective owners.
19. Contact information
For additional information, please visit: http://www.semiconductors.philips.com
For sales office addresses, send an email to: sales.addresses@www.semiconductors.philips.com
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
For more information, please visit: http://www.semiconductors.philips.com.
For sales office addresses, email to: sales.addresses@www.semiconductors.philips.com.
Date of release: 28 April 2006
Document identifier: TFA9843AJ_1
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