A good PCB layout for the LME49740 involves keeping the input and output traces short and symmetrical, using a solid ground plane, and placing the device close to the power supply bypass capacitors. Additionally, it's recommended to use a 4-layer PCB with a dedicated analog ground plane to minimize noise and interference.
The choice of gain resistors depends on the desired gain and bandwidth of the amplifier. A good starting point is to use the recommended values in the datasheet, and then adjust them based on the specific requirements of your application. It's also important to consider the tolerance and temperature coefficient of the resistors to ensure stable operation over temperature.
The maximum power dissipation of the LME49740 is 1.4W. To ensure it doesn't overheat, it's essential to provide adequate heat sinking, such as a thermal pad or a heat sink, and to keep the device in a well-ventilated area. Additionally, it's recommended to keep the device's junction temperature below 150°C to ensure reliable operation.
To filter out noise and interference, it's recommended to use a combination of passive and active filtering techniques. This can include using capacitors and resistors to filter out high-frequency noise, and using the LME49740's built-in filters to reject low-frequency noise. Additionally, it's essential to use a well-regulated power supply and to keep the circuit away from sources of electromagnetic interference.
The recommended input impedance for the LME49740 is 1kΩ to 10kΩ, and the recommended output impedance is 100Ω to 1kΩ. However, the optimal impedance values may vary depending on the specific application and the desired frequency response.
LME49740MAX/NOPB datasheet
by Texas Instruments
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