Luohe where amplifier monopoly wholesale Henan Jiaming Yang 1503 +71780 +75 www.69139139.com 1399 +229 +631 Zheng * City Market Milan sun, Unit 2, Building 5, 208 D audio amplifier features a high-efficiency, high- The advantages of the efficiency of power consumption and less heat. Amplifier efficiency is 90% and the chip package can heat 1W, then this amplifier can output power of about 10W, design of this 対 system provides great convenience. Class D amplifier efficiency can view from different angles. The highly efficient primarily because of the low output power transistor on-resistance Rds (on), if the conduction resistance of 0.4 ohms speaker impedance is 4 ohms then the output transistor is equal to 91% efficiency. However amplifier other consumption, which includes the consumption of the analog circuit, analog 転 digital mixing circuit consumption and the consumption of the digital circuit. These consumption performance in the no-load quiescent current Iq. If the power supply voltage of 5V Iq is 5mA, static power consumption is 25mW. Therefore, the calculation of the efficiency of the power amplifier needs to consider the the quiescent output transistor consumes two factors. If coupled load 25mW of power output and the efficiency of the output power transistor is 90% of the power transistor consumes approximately 2.5mW. So output 25mW of situation, the total power consumption including static consumption, consumption and output power of the power transistor, that is 25mW + 25mW + 2.5mW = 52.5mW at the moment the efficiency is 25mW/52.5mW = 48%. Calculated in the same way if the output is 250mW total power consumption is 25mW + 250mW + 25mW = 300mW, the moment efficiency 250mW/300mW = 83%. Similarly, if output of 2.5W, the total power consumption is 25mW + 2.5W + 250mW = 2.775W, the efficiency at the moment is 2.5W / 2.775W = 90%, close to the efficiency of the output power transistor. So the output power is small when the consumption of the output transistor can be ignored and the output power when a large static consumption can be ignored. If the load is equal to 4 ohms efficiency higher than 90% of the output transistor is its on-resistance of only 0.4 ohm or smaller, if BTL double-ended output, Rds (on) is caused by a PMOS and NMOS each MOS only about on-resistance of 0.2 ohms so easily lead to measurement error. Measurement when high-current path to be chosen thick lines at the same time to be welded to reduce wiring resistance. Extract a large current to maintain the stability of the power supply voltage. Since the measurement of the conduction resistance of the output power transistor is prone to error and its resistance and measurement conditions such as the amount of current or voltage, preferably the concept of a method to check the efficiency of the output power transistor CHECK efficiency curve of the efficiency of the large output power terminal, which point very close to the efficiency of the output power transistor efficiency, but it should be noted that this curve must be obtained in a resistive load conditions. If Pi represents the input power, PQ represents the static power consumption, PO represents the output power, Emos represents the efficiency of the output power transistor and Eff representing the total efficiency of their mutual relationship Po = (Pi - Pq) x EMOS and Eff of = PO / Pi merge the above formula, the total efficiency Eff = (PO x EMOS) / (Po + EMOS X PQ) if the ratio of the output power Po and static power consumption Pq Poq, Eff = (Poq x Emos) / (Poq + Emos ) This simple formula can be easily observed the relationship between the output power and overall efficiency. Therefore, if the efficiency of the power transistor EMOS = 90% and the output power Po is the of Pq by 10 times of the static power consumption, i.e. POQ = 10, the total efficiency Eff = (10 x 0.9) / (10 + 0.9) = 83%. If the efficiency of the power transistor the Emos same is 90% and the output power Po is the static power consumption Pq eight times, then the total efficiency Eff = (8 x 0.9) / (8 + 0.9) = 81%. The above examples 顕 illustrates a class D amplifier output power and a ratio of the static power consumption determines the overall efficiency, i.e., the static consumption current 対 total efficiency a certain degree of influence. In addition, if the efficiency of the power transistor Emos = 90%, a static power consumption is 25mW or 5V voltage 5mA quiescent current amplifier output power greater than 25mA x 8 = 200 mW with 81% efficiency. However, if the static power consumption is 50mW or 5V voltage 10mA quiescent current amplifier output power greater than 50mA x 8 = 400 mW can have the same efficiency, so the real efficiency need to consider the static current consumption. The above discussion does not include the consumption of the output filter circuit diagram containing the output filter the consumption output filter to calculate the static power consumption. Luohe amplifier monopoly wholesale Henan Luohe where where for amplifier sale | of Henan where to sell amplifier Jiaming Yang Zheng * City Market 1503 +71780 +75 www.69139139.com 1399 +229 +631 Milan sun Unit 2, Building 208