Analog Input /
Single End Output
Class-D Speaker Amplifier
BD5445EFV
No.11075ECT16
●Overview
BD5445EFV is a Analog input type Class D Speaker Amplifier designed for Flat-panel TVs in particular for space-saving
and low-power consumption, delivers an output power of 17W+17W. This IC employs state-of-the-art Bipolar, CMOS, and
DMOS (BCD) process technology that eliminates turn-on resistance in the output power stage and internal loss due to line
resistances up to an ultimate level. With this technology, the IC can achieve high efficiency of 91% (10W+10W output with
8Ω load).In addition, the IC is packaged in a compact reverse heat radiation type power package to achieve low power
consumption and low heat generation and eliminates necessity of external heat-sink up to a total output power of 34W. This
product satisfies both needs for drastic downsizing, low-profile structures and powerful, high-quality playback of sound
system.
●Features
1) 17W stereo single-ended outputs
34W mono bridge-tied-load output
2) Wide supply voltage (From 10V to 27V)
3) Four selectable gain (14, 20, 26, 32dB)
4) Master / Slave function
5) Soft-start and Soft-mute
6) Low noise, Low distortion
7) Various protection functions
(High temperature, Output short, Under voltage)
8) Small power package (HTSSOP-B28)
●Applications
Flat Panel TVs (LCD, Plasma), Home Audio, Desktop PC, Amusement equipments, Electronic Music equipments, etc.
Supply voltage Vcc 30 V Pin 1, 15, 16, 27, 28 ※1 ※2
1.45 W ※3
Power dissipation Pd
3.30 W ※4
4.70 W ※5
Input voltage for signal VIN -0.3 ~ 5.3 V Pin 4, 5 ※1
Input voltage for control V
Input voltage for clock V
-0.3 ~ Vcc + 0.3V Pin 2, 3, 10, 11, 13 ※1
CONT
-0.3 ~ 5.3 V
OSC
Pin 12 ※1
Operating temperature range Topr -25 ~ +85 ℃
Storage temperature range Tstg -55 ~ +150 ℃
Maximum junction temperature Tjmax +150 ℃
※1The voltage that can be applied, based on Gnd(Pin6, 20, 21, 22, 23)
※2Do not, however exceed Pd and Tjmax=150℃.
※370mm×70mm×1.6mm, FR4, 1-layer glass epoxy board (Copper on bottom layer 0%) Derating in done at 11.6mW/℃ for operating above Ta=25℃.
※470mm×70mm×1.6mm, FR4, 2-layer glass epoxy board (Copper on bottom layer 100%) Derating in done at 26.4mW/℃ for operating above Ta=25℃. There are thermal via on the board.
※570mm×70mm×1.6mm, FR4, 4-layer glass epoxy board (Copper on bottom layer 100%) Derating in done at 37.6mW/℃ for operating above Ta=25℃. There are thermal via on the board.
●Operating conditions (Ta=25℃)
Item SymbolLimit UnitConditions
Supply voltage Vcc 10 ~ 27 V Pin 1, 15, 16, 27, 28 ※1 ※2
Minimum load impedance RL 3.6 Ω
※6 Do not, however exceed Pd.
※ No radiation-proof design
=6Ω) Fig.18 Total output power-Current consumption (RL=6Ω)
L
2
1.8
1.6
1.4
1.2
1
ICC(A)
0.8
0.6
0.4
0.2
0
0510152025303540
Vcc=24V
RL=6Ω
fin=1kHz
TOTA L O UTPUT PO WER (W)
2011.10 - Rev.C
BD5445EFV
Technical Note
●Typical Characteristic Data (SE×2ch)Measured on ROHM’s evaluation board.
Dotted lines of the graphs indicate continuous output power by installing additional heat sinks.
26
24
22
20
18
16
14
12
10
Output Power (W/ch)
8
6
4
2
0
Fig.19 Power supply voltage-Output power (RL=4Ω) Fig.20 Output power-Efficiency (RL=4Ω)
●Typical Characteristic Data (SE×2ch)Measured on ROHM’s evaluation board.
Dotted lines of the graphs indicate continuous output power by installing additional heat sinks.
100
10
Vcc=24V
RL=8Ω
BW=20~20kHz
100
10
Vcc=24V
RL=8Ω
Po=1W
BW=20~20kHz
1
THD+N(%)
0.1
6kHz
1
THD+N(%)
1kHz
0.1
Technical Note
0.01
0.0010.010.1110100
OUTPUT POWER(W)
Fig.22 Output power-THD+n Fig.23 Frequency-THD+n
40
35
30
25
20
15
10
VOLTAGE GAIN(dB)
Vcc=24V
RL=8Ω
5
Po=1W
0
L=47uH
C=0.39uF
-5
-10
10100100010000100000
FREQUENCY(Hz)
Fig.24 Frequency-Voltage gain Fig.25 FFT of Output Noise Voltage
Pin name Pin voltage Pin explanation Internal equivalence circuit
GNDP1
0V Gnd pin for ch1 PWM signal
BSP1 5V Boot-strap pin of ch1
Please connect the capacitor.
25
26
OUT1 0V~Vcc Output pin of ch1 PWM
Please connect to Output LPF.
27
28
VCCP1 Vcc Power supply pin for ch1 PWM signal
●Audio input circuit (pin4 and pin5)
Connect the audio input pin with a prior-stage circuit via coupling capacitors C4 and C5. Because C4, C5 and input
impedance R4, R5 of the IC circuit compose the primary HPF, the values determine an input low-band cutoff frequency. Input
cutoff frequencies are calculated by the following formulas:
1
[]
=Cf
Hz
C4•2πR4
1
[]
=Cf
Hz
C5•2πR5
An excessively high capacitance of an input coupling capacitor results in a longer period required for stabilizing a power input
pin voltage after turning on the power supply. Note that placing the MUTEX pin (pin11) at "L" level (mute turned off) for
avoidance of Pop-noise before stabilizing an input pin. R4 and R5 are changed by Gain setting.
GAIN1
(3pin)
GAIN0
(2pin)
R4,R5 input
impedance(TYP.)
Amplifier Gain (SE) Amplifier Gain (BTL)
L L 40kΩ 14dB 20dB
L H 40kΩ 20dB 26dB
H L 26.7kΩ 26dB 32dB
H H 16kΩ 32dB 38dB
●Output LC Filter Circuit (Pins 17, 18, 25, and 26)
An output filter is required to eliminate radio-frequency components exceeding the audio-frequency region supplied to a load
(speaker). Because this IC uses sampling clock between 480kHz and 720kHz in the output PWM signals, the high-frequency
components must be appropriately removed.
This section takes an example of an LC type LPF, in which coil L
fil and capacitor Cfil compose a differential filter with an
attenuation property of -12dB/oct. A large part of switching currents flow to capacitor Cfil, and only a small part of the currents
flow to speaker R
L. The following is a table for output LC filter constants.
Speaker RL L
[μH] C
fil
[μF] C
fil1
fil2
[μF]
4Ω 22 0.68 ―
SE output
6Ω 33 0.47 ―
8Ω 47 0.39 ―
4Ω 15 0.22 1
BTL output
6Ω 22 0.15 0.68
8Ω 33 0.1 0.47
In SE(single end) applications, the dc blocking capacitor (Cse) and speaker impedance compose the primary HPF. The cutoff
frequency is determined by
=Cf
2πC
SE
1
[]
Hz
R•
L
The following table is Cse setting at cutoff frequency 20Hz, 40Hz, and 60Hz.
Please connect ROSC terminal (pin 9) to 22kohm resister for setting master mode.
※
※Please connect to the following filter, and input clock (duty = 50%) to OSC terminal (pin 12) for setting slave mode.
PWM Sampling frequency is sited from input clock. If input clock have noise (ex.Jitter), noise appear to Speaker output.
High level input voltage (Max.voltage) of tease control pin is equal to Vcc voltage. But absolute max.voltage of
※
In0(pin4),ROSC(pin9),OSC(pin12) and REG_G(pin14) is 5.3V. Tease pins may break, when short next pins. If these pins
short to Vcc, connecting through 10k
Fig.32 ROSC terminal filter circuit for setting slave mode.
Power supply shut down, after PDX (Pin 10) change H→L. The IC has possibly to sound POP noise, if PDX (Pim10) keep
H. Speaker’s coupling capacitor (Fig30:Cse) don’t discharge at this time. Pop-noise may sound when power supply start up
at the next time.
●Power supply start-up and shut-down sequence for single control
Short between PDX(Pin 10) and MUTEX(Pin 11), enable to control these pins at one time.
PDX (Pin 10) and MUTEX (Pin 11) set low at one time, while this IC is on normal mode, the IC don't operate soft-mute. If low
frequency and high level signal input this time, the IC has possibility to sound POP-Noise. To avoid this POP-Noise configure
the following circuit, because PDX (Pin10) enables to change low after MUTEX (Pin11) have changed. This sequence make
less POP-Noise because the IC can operate soft-mute.
PD/MUTE Control
MUTEX
R
10
C
10
PDX
11
10
110KΩ
90KΩ
110KΩ
90KΩ
τH=R10×C10
τL=(R10+200KΩ)×C10
Control configuration for soft-mute operation by single control
※ All protection functions are restored automatically when the fault is removed.
Detecting & Releasing condition
Detecting current = 10A (TYP.) HiZ_Low
Release from Vcc or Gnd short
Chip temperature to be above 150℃ (TYP.) HiZ_Low
Chip temperature to be below 125℃ (TYP.)
Power supply voltage to be below 8V (TYP.) HiZ_Low
Power supply voltage to be above 9V (TYP.)
PWM
Output
Normal
operation
Normal
operation
Normal
operation
1)Output short protection(Short to the power supply)
This IC has the output short protection circuit that stops the PWM output when the PWM output is short-circuited to the
power supply due to abnormality.
Detecting condition – It will detect when PDX pin is set High and the current that flows in the PWM output pin becomes
10A(TYP.) or more. The PWM output instantaneously enters the state of HiZ-Low if detected, and IC
does the latch.
Releasing method – This IC detect releasing from Vcc short every 220msec(TYP.). Normal operation is restored when
releasing from Vcc short.
Vcc short
Release from Vcc short
OUT1(Pin 25,26)
OUT2(Pin 17,18)
Current
10A(TYP.)
Speaker output
: Vcc short
Speaker output
: Hiz-Low release
from Vcc short
Speaker output
: Normal operation
IC restores automatically
release from Vcc short
This IC has the output short protection circuit that stops the PWM output when the PWM output is short-circuited to Gnd due
to abnormality.
Detecting condition – It will detect when PDX pin is set High and the current that flows in the PWM output terminal becomes
10A(TYP.) or more. The PWM output instantaneously enters the state of HiZ-Low if detected, and IC
does the latch.
Releasing method – This IC detect releasing from Gnd short every 220msec(TYP.). Normal operation is restored when
releasing from Gnd short.
(※)Remark of output short protection
Circuit current changes suddenly, when IC detects output short protection. At this time IC may break, because supply
voltage rise up by back electromotive force. Decoupling capacitors (VCCPI and VCCP2) should be placed as close to the
IC as possible. (recommend 4.7μF or more.)
This IC has the high temperature protection circuit that prevents thermal reckless driving under an abnormal state for the
temperature of the chip to exceed Tjmax=150℃.
Detecting condition - It will detect when PDX pin is set High and the temperature of the chip becomes 150℃(TYP.) or more.
The speaker output is muted through a soft-mute when detected.
Releasing condition - It will release when PDX pin is set High and the temperature of the chip becomes 120℃(TYP.) or less.
The speaker output is outputted through a soft-start when released.
This IC has the under voltage protection circuit that make speaker output mute once detecting extreme drop of the power
supply voltage.
Detecting condition – It will detect when PDX pin is set High and the power supply voltage becomes lower than 8V.
The speaker output is muted when detected.
Releasing condition – It will release when PDX pin is set High and the power supply voltage becomes more than 9V.
The speaker output is outputted through a soft-start when released.
Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range may
result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open mode) when
such damage is suffered. A physical safety measure such as a fuse should be implemented when use of the IC in a
special mode where the absolute maximum ratings may be exceeded is anticipated.
2 ) Power supply lines
As return of current regenerated by back EMF of output coil happens, take steps such as putting capacitor between
power supply and Gnd as a electric pathway for the regenerated current. Be sure that there is no problem with each
property such as emptied capacity at lower temperature regarding electrolytic capacitor to decide capacity value. If the
connected power supply does not have sufficient current absorption capacity, regenerative current will cause the
voltage on the power supply line to rise, which combined with the product and its peripheral circuitry may exceed the
absolute maximum ratings. It is recommended to implement a physical safety measure such as the insertion of a
voltage clamp diode between the power supply and Gnd pins.
3 ) Gnd potential (Pin 6, 20, 21, 22, 23)
Ensure a minimum Gnd pin potential in all operating conditions.
4 ) Input terminal
The parasitic elements are formed in the LSI because of the voltage relation. The parasitic element operating causes
the wrong operation and destruction. Therefore, please be careful so as not to operate the parasitic elements by
impressing to input terminals lower voltage than Gnd. Please do not apply the voltage to the input terminal when the
power-supply voltage is not impressed.
5 ) Setting of heat
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating
conditions. This IC exposes its frame of the backside of package. Note that this part is assumed to use after providing
heat dissipation treatment to improve heat dissipation efficiency. Try to occupy as wide as possible with heat dissipation
pattern not only on the board surface but also the backside.
Class D power amplifier is High efficiency and low heat generation by comparison with conventional Analog power
amplifier. However, In case it is operated continuously by maximum output power, Power dissipation(Pdiss) may
exceed package dissipation. Please consider about heat design that Power dissipation(Pdiss) does not exceed
Package dissipation(Pd) in average power(Poav). (Tjmax :Maximum junction temperature=150℃, Ta :Peripheral
temperature[℃], θja :Thermal resistance of package[℃/W], Poav:Average power[W], η:Efficiency)
Use caution when using the IC in the presence of a strong magnetic field as doing so may cause the IC to malfunction.
7 ) Thermal shutdown circuit
This product is provided with a built-in thermal shutdown circuit. When the thermal shutdown circuit operates, the
output transistors are placed under open status. The thermal shutdown circuit is primarily intended to shut down the IC
avoiding thermal runaway under abnormal conditions with a chip temperature exceeding Tjmax = 150℃.
8 ) Shorts between pins and misinstallation
When mounting the LSI on a board, pay adequate attention to orientation and placement discrepancies of the LSI. If it
is misinstalled and the power is turned on, the LSI may be damaged. It also may be damaged if it is shorted by a
foreign substance coming between pins of the LSI or between a pin and a power supply or a pin and a Gnd
9 ) Power supply on/off (Pin 1, 15, 16, 27, 28)
In case power supply is started up, PDX (Pin 10) and MUTEX (Pin 11) always should be set LOW, And in case power
supply is shut down, it should be set LOW likewise. Then it is possible to eliminate pop noise when power supply is
turned on/off. And also, all power supply terminals should start up and shut down together.
10 ) Precautions for Speaker-setting
If the impedance characteristics of the speakers at high-frequency range while increase rapidly, the IC might not have
stable-operation in the resonance frequency range of the LC-filter. Therefore, consider adding damping-circuit, etc.,
depending on the impedance of the speaker.
Measuring instrument:TH-156(Kuwano Electrical Instruments Co., Ltd.)
Measuring conditions:Installation on ROHM’s board
Board size:70mm×70mm×1.6mm(with thermal via on board)
Material:FR4
・The board on exposed heat sink on the back of package are connected by soldering.
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Examples of application circuits, circuit constants and any other information contained herein
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