MD3303 [ETC]
D3303 集成了一个数字音量控制的3W*2 的D类功放，它可以用“升(红)”，“降(黑)”两个按键控制，一共有6?级。这是第一个把数字音量控制集成在一起的D 类放大器，从而提高了集成度，进一步减少了外部集成电路数，降低了整机成本。MD3303是一个无滤波器立体声D级音频放大器。具有低THD＋N高质量语音再生功能，无滤波器的新型直接输出驱动扬声器无需低通滤波器，具有低成本占用面积小。在5V供电4Ω（8Ω）负载具有10％THD的3W.无滤波器，低静态电流，低THD，超低噪音，低EMI.高效90％，超低噪音，短路保护，温度保护，少量外围元件。适用范围：LCD监视器／投影电视笔记本电脑，便携式扬声器，便携式DVD播放器，移动通信电话。封装：有SSOP-24和SOP-16 二种封装。;
| 型号： | MD3303 |
| 厂家： | 
ETC |
| 描述： | D3303 集成了一个数字音量控制的3W*2 的D类功放，它可以用“升(红)”，“降(黑)”两个按键控制，一共有6?级。这是第一个把数字音量控制集成在一起的D 类放大器，从而提高了集成度，进一步减少了外部集成电路数，降低了整机成本。MD3303是一个无滤波器立体声D级音频放大器。具有低THD＋N高质量语音再生功能，无滤波器的新型直接输出驱动扬声器无需低通滤波器，具有低成本占用面积小。在5V供电4Ω（8Ω）负载具有10％THD的3W.无滤波器，低静态电流，低THD，超低噪音，低EMI.高效90％，超低噪音，短路保护，温度保护，少量外围元件。适用范围：LCD监视器／投影电视笔记本电脑，便携式扬声器，便携式DVD播放器，移动通信电话。封装：有SSOP-24和SOP-16 二种封装。 音频放大器 电视 监视器 电脑 驱动 CD DVD 便携式 通信 |
| 文件： | 总12页 (文件大小：984K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Key Features
General Description
3W Output at 10% THD with a 4Ω Load and 5V Power The MD3303 is a 3W,class-D audio amplifier with
supply
64-step digital volume control. It offers low
THD+N,allowing it to produce high-quality sound
reproduction .The new filterless architecture allows
the device to drive the speaker directly without
needing low-pass output filters which will save 30%
system cost and 75% PCB area.
Filterless,Low Quiescent Current and low EMI
Low THD+N
64-step Digital Volume Control
Superior Low Noise
Efficiency up to 90%
Short Circuit Protection
Thermal Shutdown
With the same numbers of external components .the
efficiency of the MD3303 is much better than class-ab
Few External Components to Save Space and Cost cousins, It can extend the battery life ideal for
Pb-Free Package
portable applications.
The MD3303 is available in SSOP-24 and SOP-16 package.
Applications
Lcd Monitors/TV Projectors
Notebook Computer
Portable Speakers
Portable DVD Players, Game Machines
Cellular Phones/Speaker Phones
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
*The remark value are only for reference
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Pin Descriptions
MD3303 SSOP24
MD3303 SOP16
Pin Numbe
Pin Name
Description
Pin Numbe
Pin Name
-OUT_L
PGND
Description
Left Channel Negative Output
Power GND
1
2
3
4
5
6
7
-OUT_L
PGND
Left Channel Negative Output
Power GND
1
2
3
4
5
6
7
PGND
Power GND
+ OUT_L
PVDD
Left Channel Positive Output
Power VDD
+ OUT_L
PVDD
Left Channel Positive Output
Power VDD
VDD
Analog VDD
/MUTE
VDD
Mute Control Input(active low),pull-up
Analog VDD
INL
Left Channel Input
VREF
Internal analog reference, connect a bypass
capacitor from VREF to GND
Volume down Control(active low)
Volume up Control(active low)
Right Channel Input
8
9
INL
NC
Left Channel Input
8
9
DN
UP
No Connect
10
VREF
Internal analog reference, connect a bypass
capacitor from VREF to GND
No Connect
10
INR
11
12
13
14
15
16
17
18
19
20
21
22
23
24
NC
NC
11
12
13
14
15
16
GND
/SHDN
+OUT_R
PGND
Analog GND
No Connect
Shutdown Control Input(active low),pull-down
Right Channel Positive Output
Power GND
DN
Volume down Control(active low)
Volume up Control(active low)
Volume Controller Reset (active low)
No Connect
UP
RST
PVDD
Power VDD
NC
-OUT_R
Right Channel Negative Output
INR
Right Channel Input
GND
Analog GND
/SHDN
PVDD
+OUT_R
PGND
PGND
-OUT_R
Shutdown Control Input(active low),pull-up
Power VDD
Right Channel Positive Output
Power GND
Power GND
Right Channel Negative Output
Absolute Maximum Ratings
These are stress ratings only and functional operation is not implied, Exposure to absolute maximum ratings
for prolonged time periods may affect device reliability. All voltages are with respect to ground
Supply Voltage at no Input Signal………………….6.0V Maximum Junction Temperature…………………..150℃
Input Voltage………………………….-0.3V to VDD+0.3V Storage Temperature………………………-65℃ to 150℃
Soldering Temperature……………………..300℃,5sec
Recommended Operating Conditions
Supply voltage Range………………………….2.2V to Ambient Temperature Range………………-40℃ to 85℃
5.5V
Junction Temperature RANGE……………-20℃ to 125℃
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Thermal Information
Parameter
Symbol
Package
Maximum
Unit
Thermal Resistance(Junction to Ambient)
θJA
SSOP-24(SOP-16)
96
℃/W
Electrical Characteristic
V
DD =5V, Gain=18db, R
L
=8Ω,TA=25℃,unless otherwise noted.
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Typical Operating Characteristics(TA=25) ℃
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Typical Operating Characteristics(continued)
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Gain Setting(VDD=5V)
Step Gain(dB) Step Gain(dB) Step Gain(dB) Step Gain(dB)
1
2
-75.0
-39.7
-34.0
-28.2
-22.4
-16.5
-10.5
-8.0
-5.5
-2.9
-0.4
1.1
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
4.8
5.1
5.5
5.9
6.3
6.7
7.1
7.5
7.9
8.3
8.7
9.1
9.6
10.0
10.4
10.7
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
11.2
11.6
12.0
12.3
12.7
13.2
13.6
14.0
14.4
14.8
15.2
15.6
16.0
16.4
16.8
17.2
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
17.6
18.0
18.4
18.8
19.2
19.6
20.0
20.4
20.9
21.3
21.7
22.1
22.5
22.9
23.4
23.8
3
4
5
6
7
8
9
10
11
12
13
14
15
16
2.6
3.6
4.0
4.4
Power on gain or gain after reset.
Note: Gain could have 1dB deviation device to device.
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Application Notice
1. When MD3303 Works without filter. We must connect the speaker before turn on. Else, it will be easy to
damage the chip.
2. When MD3303 works without filter,it will be best that adding a ferrite chip bead at the outgoing line of
speaker in order to suppress possible electromagnetic interference.
3. The absolute maximum rating of operation voltage is 6V power regulator;even the chip can deliver 4W sine
wave with a 40hm speaker,it is not recommended for long term using due to the heat dissipation. But if the
input signal is a music signal, then it can work in long term since the average power output is much less
than4W. Whenusingdrybatterycell,weshouldnotice that if the batter cell is 4 new dry batteries or alkaline
batteries,even the voltage will be over 6V,it still can work safety.Since the output voltage of the 4 pack
of new drybatteries will be reduced very quickly after turn on due to the internal resistance of the
battery.There is no dangerous of damaging the chip when playing music or speech, even use 4 new dry batteries.
To reduce the effect of the increasing of internal resistance of batter after long term discharging , it is
recommended to connect a 1000uF electrolytic capacitor between the power supply and the ground.
4. Because digital volume control has big gain, we can not make input signal too high to cause the clipping
of the output signal when increase volume,also it may damage the chip.
1. The AP-AUX-0025 low pass filter is necessary for every class-D amplifier measurement done by AP analyzer.
2. Two 22μH inductors are used in series with load resistor to emulate the small speaker for efficiency
and quiescent current measurement.
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Application Information
Maximum Gain
As shown in block diagram(page 2),the MD3303 has two internal amplifiers stage. The first stage’s gain is
externally configuerable, while the second stage’s is internally fixed in a fixed-gain of the first stage
is set by selecting the ratio of R
f
to Ri while the second stage’s gain is fixed at 2x.Consequently,the
differential gain for the IC IS
A
VD=20*log[2*(R
f
f
/R
i
)]
The MD3303 sets maximum R
=218kΩ and minimum R
i
=27kΩ, thus the maximum closed-ggain is 24dB.
Digital Volume Control(DVC)
The MD3303 features a digital volume control which consists of the UP,DN and RST pins ,An internal clock is
used where the clock frequency value is determined from the following formula:
F
clk=fosc/213
The oscillator frequency fosc value is 250kHz typical, with ±20% tolerance. The DVC’s clock frequency
is 33Hz(cycle time 300ms)typical.
Volume changes are then effected by toggling either the UP or DN pins with a logic low .After a period of
3.5 clocks pulses with either the UP or DN pins held low ,the volume will change to the next specified step,
eitherUPorDN, andfollowedbyashortdelay.This delay decreases the longer the line is held low, eventually
reaching a delay of zero, The delay allows the user to pull UP or DN terminal low once for one volume change ,or
hold down to ramp several volume changes. The delay is optimally configured for push button volume control.
If either the UP or DN pin remains low after the first volume transition the volume will change again ,but
this time after 9.5 clock pulses. The followed transition occurs at 2 clock pulses for each volume transition.
This is intended to provide the user with a volume control that pauses briefly after initial application,
and then slowly increases the rate of volume change as it is continuously applied. This cycle is shown in
the timing diagram shown in figure 1.
Thereare64discretsgainsettingsrangingfrom+24dBmaximumto-75dBminimum, Upondevicepoweronorapplied
a logic low to the RST pin,the amplifier’s gain is set to a default value of -4.5dB.However, when coming
out of mute mode, the MD3303 will reset back to its previous gain setting.Volume levels for each step vary
and are specified in Gain Setting table on page 7.
If both the UP and DN pins are held high,no volume change will occur.Trigger points for the UP and DN pins
are at 70% of VDD minimum for a logic high ,and 20% of VDD maximum for a logic low.It is recommended, however,
to toggle UP and DN between VDD and GND for best performance
Mute Operation
The MUTE pin is an input for controlling the output state of the MD3303,A logic high on this pin enables the
outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent
current is listed in the electrical characteristic table .The MUTE pin can be left floating due to the pull-up
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
internal.
Shutdown operation
In order to reduce power consumption while not in use, the MD3303 contains shutdown circuitry that is used
to turn off the amplifier’s bias circuitry. This shutdown feature turns the amplifier off when logic low
is placed on the SHDN pin. By switching the SHDN pin connected to GND, the MD3303 supply current draw will
be minimized in idle mode .The SHDN pin cannot be left floating due to the pull-down internal.
Power supply decoupling
functions .During start-up or recovery from shutdown
The MD3303 is a high performance CMOS audio amplifier mode, CBYD determines the rate at which the amplifier
that requires adequate power supply decoupling to starts up.The second function is to reduce noise
ensure the output THD and PSRR are as low as poooible. produced by the power supply caused by coupling into
Power supply decoupling is affecting low frequency the output drive signal.This noise is from the
response. Optimum decoupling is achieved by using two internal analog reference to the amplifier,which
capacitors of different types that target different appears as degraded PSRR and THD+N.
types of noise on the power supply leads.For higher Bypass capacitor(CBYP) values of 0.47μF to 1.0μF
frequency transients,spikes, or digital hash on the ceramic is recommended for the best THD AND NOISE
line, a good low equivalent series resistance PERFORMANCE.Increasing the bypass capacitor reduces
(ESR)ceramic capacitor,typically
1.0μF,placed clicking and popping noise from power on/off and
as close as possible to the device VDD terminal works entering and leaving shutdown.
best.For filtering lower-frequency noise signals,a Under Voltage Lock-out(UVLO)
larger capacitor of 10μF(ceramic)or greater placed The MD3303 incorporates circuitry designed to detect
near the audio power amplifier is recommended.
Input Capacitor(C
when the supply voltage is low.When the supply voltage
drops to 1.85v or below,the MD3303 outputs are
i
)
Large input capacitors are both expensive and space disable,and the device comes out of this state and
hungry for portable designs. Clearly, a certain sized starts to normal functional when the supply voltage
capacitor is needed to couple in low frequencies increases.
without severe attenuation.But in many cases the Short Circuit Protection(SCP)
speakers used in portable systems,whether internal or The MD3303 has short circuit protection circuitr on
external,have little ability to reproduce signals the outputs that prevents damage to the device during
below 100Hz to 150Hz.Thus,using a large input output-to-outputandoutput-to-GNDshort.Whenashort
capacitor may not increase actual system performance. circuit is detected on the outputs,the outputs are
In this case,input capacitor(C
i
)and input resistance disable immediately.If the short was removed,the
(Ri)of the amplifier form a high-pass filter with the device activates again.
cornerfrequencydeterminedequationbelowfc=1/2TTRiCi Over Temperature Protection
In addition to system cost and size,click and pop Thermal protection on the MD3303 prevents damages to
performance is affected by the size of the input the device when the internal die temperature exceeds
coupling capacitor, Ci A larger input coupling 150℃.Thereisa15degreetoleranceonthistrippoint
capacitor requires more charge to reach its quiescent fromdevicetodevice.Oncethedietemperatureexceeds
DC voltage(nominally 1/2 VDD).This charge comes from the thermal set point,the device outputs are
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
the internal circuit via the feedback and is apt to disabled.Thisisnotalatchedfault.Thethermalfault
create pops upon device enable.Thus,by minimizing the is cleared once the temperature of the die is reduced
capacitor size based on necessary low frequency by 60℃ .This large hysteresis will prevent motor
response, turn-on pops can be minimized
Analog Reference Bypass Capacitor(CBYD
boating sound well and the device begins normal
operation at this point with no external system
)
The Analog Reference Bypass Capacitor(CBYD)is the most interaction.
critical capacitor and serves several important
A simple solution is to put an additional capacitor
How to Reduce EMI(Electro Magnetic Interference)
Channel specific. A tow channels amplifier has two
1000μF at power supply terminal for power line nutually exclusive channels and consequently must
coupling if the traces from amplifier to speakers are have tow mutually exclusive output noise ground
short(<20cm).
traces. The layout of the MD3303 offers separate PGND
Most applications require a ferrite bead filter which connections for each channel and in some cases each
shows at Figure 3.The ferrite filter reduces EMI side of the bridge. Output noise grounds must tie to
AROUND 1 MHz and higher.When selecting a ferrite system ground at the power in exclusively. Signal
bead.choose one with high impedance at high currents for the inputs, reference. Etc need to be
frequencies ,but low impedance at low frequencies.
returned to quite ground. This ground only ties to the
signal components and the GND pin ,GND then ties to
system ground.
Power Supply Line
As same to the ground, VDD and each channel PVDD need
to be separated and tied together at the system power
supply. Recommend that all the trace could be routed
as short and thick as possible. For the power line
layout, just imagine water stream, any barricade
PCB layout Guidelines
Grounding
At this stage it is paramount that we acknowledge the placed in the trace(shows in figure 4)could result in
need for separate grounds. Noise currents in the the bad performance of the amplifier.
output power stage need to be returned to output noise
ground and nowhere else. Were these currents to
circulate elsewhere, may get into the power supply.
The signal ground.etc, worse yet, they may form a loop
and radiate noise. Any of these instances results in Components Placement
degraded amplifier performance. The logical returns The power supply decoupling capacitors need to be
for the output noise currents associated with Class-D placed as close to VDD and PVDD pins as possible.The
switching are the respective PGND PINS TOR EACH inputs need to be routed away from the noisy trace.
CHANNEL.The switch state diagram illustrates that The VREF bypass capacitor also needs to be close to
PGNDisinstrumentalinnearlyeveryswitchstate.This the pin of IC very much.
is the perfect point to which the output noise ground
trace should return. Also note that output noise
ground is
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
MD3303
Filterless 3W Class-D Stereo Audio Amplifier
With Digital Volume Control
Dimensions Millimeters
Symbol
Min
Max
A
A1
A2
B
1.350
0.100
1.350
0.330
0.190
9.800
3.800
5.800
1.750
0.250
1.550
0.510
0.250
10.000
4.000
6.300
C
D
E
E1
e
1.270（TYP）
L
0.400
0°
1.270
8°
θ
电话:0755-82709111 827091112 827091113
传真:0755-82709114
地址:深圳市福田区中航路鼎诚国际大厦南座2805 室
网址:Http://www.YR-IC.com
相关型号：
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