Feature description

lm3886 is a high -performance audio power supply 23 # 8226 ; 68W, VCC output power is 4Ω continuous output of 68W ± 28V continuously output 68W ± 28V The average power of 4Ω load and 38W to 8Ω

38W continuous output power, from 20Hz to 20kHz, 8Ω when VCC 0.1%Thd+N. The performance of 8 volts LM3886, using its own

under VCC, the 50W continuous output power is 8Ω peak instantaneous temperature (° KE) (sharp peak) ± 35V protection circuit, attributed it as a discrete level [ 123]

135W instantaneous peak output power and hybrid amplifier, functional dynamic protection security operation area (SOA). Skill protection refers to the signal -to -noise ratio of these parts ≥92dB completely protected at the output end

Enter the mute function over pressure, underload, overload, including short circuit

short -circuit or power supply short circuit, short -distance power supply, short circuit, short circuit, short circuit, short circuit, short circuit, The heat -out and instantaneous output protection reaches the power through the peak of the internal current limit temperature. The circuit LM3886 maintains a good signal -to -noise ratio

Output overvoltage protection, the anti -ratio is greater than 92DB, and has a typical low noise 2.0 μV inductive load floor. It shows that the extremely low THD+N rated output value is 0.03%to enter the rated

Power -owned pressure protection, and it is not allowed to load on the audio frequency spectrum. The linear relationship with a typical rated value is 12V, so it eliminates 0.004%openness.

11 Diversion to -220 package

Wide power supply range 20V-94V

Moto stereo

Small stereo [123 ]

Self -supply vocal speakers

Vision Sound amplifier

High -end stereo TV

depending on the optional component of specific design requirements. See external components description of the function description of the component.

Preliminary: Please call your local Texas instrument sales representative or dealer to obtain availability

(1) LM3886T packaging TA11B is a non -isolation package, When the LM3886 is only installed on the radiator with only thermal compounds. If the cloud mother pad is also used in addition to the thermal compound, the θCS (case-to-sink) increases, but the radiator will be isolated from the V negative pole.

These devices have limited built -in ESD protection. The wire should be shortened together, or the device is placed in the conductive bubble during the storage or handling process to prevent static electricity from damaging the MOS gate.

(1) Unless there are other regulations, all voltages are measured relative to ground pins (pins 7).

(2) Absolute maximum rated value indicates the limit where the device may be damaged. Run the rated value indicates the function of the device. DC and AC electrical specifications of specific performance restrictions under the special test conditions of electrical characteristics. This assumes that the device is within the scope of the working ratio. Typical values are good to indicate equipment performance.

(3) If you need military/aviation special equipment, please contact the Texas Instrument Sales Office/dealer to obtain availability and specifications.

(4) The maximum rated value of the differential input voltage is based on the power supply voltage V+ +40V and V- -40V.

(5) For equipment running at the temperature of the shell higher than 25 ° C, it must be based on the maximum moderate mild temperature resistance θjc 1.0 ° C/w (connected to the shell) at the highest node of 150 ° C. See Application information precautions under the heat processing in Figure 50.

(6) Human model, 100 PF passes through 1.5 kΩ resistors.

(7) The maximum temperature of the working knot is 150 ° C, but the temperature of the instantaneous safety working area is 250 ° C.

(1) Unless there are other regulations, all voltages are measured relative to ground pins (pins 7).

(2) Absolute maximum rated value indicates the limit where the device may be damaged. Run the rated value indicates the function of the device. DC and AC electrical specifications of specific performance restrictions under the special test conditions of electrical characteristics. This assumes that the device is within the scope of the working ratio. Typical values are good to indicate equipment performance.

(3) The working voltage is as high as 84V. For more information, see the heat factors. (See Figure 5)

Electric characteristics (1) (2)

The following specifications are applicable to V+ +28V, V -28V, Imute -0.5ma, RL 4O, unless unless There are other regulations. Restricted to TA 25OC.

(1) Unless there are other regulations, all voltages are measured relative to ground pins (pins 7).

(2) Absolute maximum rated value indicates the limit where the device may be damaged. Run the rated value indicates the function of the device. DC and AC electrical specifications of specific performance restrictions under the special test conditions of electrical characteristics. This assumes that the device is within the scope of the working ratio. Typical values are good to indicate equipment performance.

(3) The typical value is measured at 25 ° C, which represents the number of parameters.

(4) Limit is specified as AOQL (average qualitylevel).

(5) In order to make the underwriter protection circuit fail, V -'s pins must have at least-9V ground reference voltage.

(6) AC electrical test; see Test Circuit 2 -AC Electric Test Circuit.

(7) The feedback compensation network limits the bandwidth of the closed -loop response, so due to high frequency rolling. Without feedback compensation, the rotation rate is usually greater.

(8) DC electricity test; see test circuit 1-DC electricity test circuit.

(9) The output voltage is the power supply voltage cut off the wave voltage. See Typical Performance Characteristics Figure 14.

General features Static function: LM3886's mute function allows users to allow users By leading to a current from the device's pin 8, which is less than 0.5 mAh. For example, the application circuit with a typical negative power voltage is combined with the switch. The switch (when it is turned on) to cut off the current from the tactile 8 to V negative electrode, so LM3886 is placed in the mute mode. See the characteristics of Figure 44 and Figure 45 in typical properties. The resistance RM is based on the following directions:

Impurd protection: When the system is powerfully power, the underwriting voltage protection circuit allows the power supply before opening LM3886, the power supply and the corresponding lid will be close to all of them. In this way, the peak of DC output will appear. After the shutdown, the output of LM3886 will not occur when the power supply will not occur during power off. Overvoltage protection: LM3886 contains overvoltage protection circuits, which limits the output current to about 11APEAK. At the same time, the voltage clamp is provided, but the diode is not performed by internal clamping. The clamping effect is exactly the same. Peak protection: LM3886 The protective crystal tube array with a peak temperature stress when the power supply is transmitted to the power supply. Figure 4 in the typical performance characteristics shows the equipment operation area, where the peak protection circuit is not enabled. The waveform on the right side of the SOA diagram shows how dynamic protection will cause waveform distortion when enabled. Heat protection: LM3886 has a complex thermal protection solution to prevent long -term heat from applying pressure on equipment. When the mold temperature reaches 165 ° C, LM3886 is closed. It started running again when the mold temperature dropped to about 155 ° C, but if the temperature began to rise and close again at 165 ° C again. Therefore, allowing the device to heat up to a relatively high temperature temperature If the failure is temporary, the continuous failure will cause the device to pass the heat stop temperature between 165 ° C and 155 ° C by the device. The cycle greatly reduces the stress applied to the integrated circuit, thereby improving its continuous fault conditions. Because the mold temperature directly depends on the radiator, the radiator should be discussed in the heat consideration in order to operate normally. In the systemThe use of the best radiator as much as possible in the cost and space limit range will improve the long -term reliability of any power semiconductor device.

Thermal factors

Heating

For high -power audio amplifiers, the heat sink is completely to keep the mold temperature at a level that does not work under normal circumstances. The radiator should choose to dissipate maximum IC power under a given power supply voltage and rated load. When the high -power pulse lasts more than 100 milliseconds, it does not use a radiator. Therefore, the shell temperature measured at the center of the packaging bottom depends on the design of the radiator and the installation of IC to the radiator. For your audio amplifier application, please refer to the correct radiator. Since semiconductor manufacturers cannot control which heat dissipation tablets are used in specific amplifiers design, we can only notify the system designer to determine the parameters and methods required for the calories to sink. Considering this, the system designer must choose his power voltage, rated load, and expected output power level to understand the ambient temperature around the device. In addition to knowing the maximum mild heat resistance of the integrated circuit,

As a benefit to the system design, we provide Figure 34 for various load characteristics in typical properties to give specific amplifiers The accurate digital design that needs to be maximized. This data is based on θjc 1 ° C/w and θcs 0.2 ° C/W. We also provide part of the θcs of the heat sink can be the determination of any audio amplifier design with different values. It is worth noting that behind the maximum power in the dissipating integrated circuit, it is to provide low -toch resistance thermal transmission for devices, such as radiator. Therefore, it is necessary for system designers to conservative radiator calculations. Generally, the lower the heat resistance of the radiator, the more the power may dissipate. Of course, this is determined by the cost and scale requirements of the system. For running cooling radiator, it can be bought in business, and its rated value should consult the manufacturer. The IC is needed correctly to minimize the heat drop between the package and the radiator. This radiator must also have sufficient metals from the bottom of the packaging center to the bottom of the packaging center to the heat sink, and no excessive temperature decreases. When installing, you should use hot lubricating fat, such as Wakefield 120 or thermaloloy Thermacote to the radiator. Without this compound, the thermal resistance will not exceed 0.5 ° C/W, and it may be worse. When using this compound, the thermal resistance will be 0.2 ° C/W or lower. It is assuming that the inch combination plane deviation below 0.005 packaging and the radiator. Correctly tightening the installation bolt is very important to determine according to the specifications of the radiator manufacturer. Whether it is necessary to isolate V-from the radiator, a insulation pad is needed. Hard pads, green pillar oxides, anode alumina, and Yunmu need to use thermal compounds on both sides. 2 The most common interface resistance with compounds with compounds is about 0.4 ° C/W. Silicon rubber pads are also available. The thermal resistance of 0.5 ° C/W does not contain the thermal compound. Experience shows that these rubber cushions are damaged, if IC is offered. Determine the mostThe power consumption in the packaging of large power consumption integrated circuits is a very important parameter, and you need to understand whether to get the best power output. The incorrect calculation of the maximum power consumption (PD) may lead to insufficient heat dissipation, resulting in the operation of the heat shutdown circuit and restricting the output power. The following formulas can be used to accurately calculate the maximum peaceful integrated circuit power and design power consumption for your amplifier without the power supply voltage, rated load and output power. These equations can be directly applied to the typical performance characteristics in Figure 35. Equal 2 cases show the maximum power consumption of the integrated circuit, equivalent 3, and the four cases of equal formulas show the average integrated circuit power consumption in different forms.

Once the correct radiator is known, once the power supply voltage, rated load, and maximum integrated circuit power consumption output power of the required radiator can calculate the maximum heat of the radiator The block (the unit is ° C/W). This calculation is made of Formula 6, based on the hot current parameters similar to the current current attribute of the electric. As we all know, LM3886's thermal resistance θjc (pair -paired shell) is usually 1 ° C/W, and the use of thermal alloy thermal carbonate thermal compounds provide about 0.2 ° C/W. It can be seen that the thermal resistance (environment) from the mold (connection) to the external air is a combination of three thermal resistances, two of which are known, θjc and θcs. Because the current heating (dispersing power consumption) is similar to the current, the thermal resistance is similar to the power resistance and the temperature drop and the voltage drop. The power consumption of LM3886 is equal to:

However, because we know the application of the application PDMAX, θJC, and θSC, and we are looking for θsa, so we have the following content: θsa [(TJMAX-Tamb) --- PDMAX (θJC+θCS)]/PDMAX (6) must be pointed out again that the value of θsa depends on the value of θsa depends on the value of θsa. System designer's amplifier application and the corresponding parameters as mentioned earlier. If the ambient temperature of the audio amplifier is working at a temperature higher than the normal 25 ° C, the heat resistance of the radiator (considering all other factors) is equal, and it needs to be smaller. Formula 2 and equation 6 are the only equation resistance required to determine the maximum hot sink. Of course, this is because the system designer knows the load and parameters provided by the load and semiconductor manufacturer provided by the power supply voltage required by the rated value of its rated value. These parameters are the shell thermal resistance θJC, TJMAX 150 ° C, and the recommended heat alloy thermal electrone thermal composite resistance, θcs. When the signal -to -noise ratio is measured, the misunderstanding of the actual measurement value is ordinary. One amplifier may sound much more quiet than another, but because of incorrect testing technology, they look equal in size. In comparative integrated circuit design and discrete circuits, this amplifier design often occurs. Divided transistor amplifiers often exhaust the gain " under high frequency