A good PCB layout for the LM1875T/LB03 involves keeping the input and output stages separate, using a star-ground configuration, and placing the decoupling capacitors close to the IC. Additionally, using a 4-layer PCB with a dedicated ground plane can help reduce noise and electromagnetic interference (EMI).
The gain resistors (Rf and Ri) determine the overall gain of the amplifier. A higher ratio of Rf to Ri results in higher gain, but also increases the noise floor. A good starting point is to use the recommended values in the datasheet, and then adjust based on the specific application requirements. It's also important to consider the tolerance and temperature coefficient of the resistors to ensure stable operation.
A single-supply voltage configuration is simpler and more common, but it can result in a lower output voltage swing and more distortion. A dual-supply voltage configuration provides a larger output voltage swing and lower distortion, but requires more complex power supply design and can be more expensive. The choice depends on the specific application requirements and design constraints.
To ensure stability, it's essential to follow the recommended component values and PCB layout guidelines. Additionally, using a compensation capacitor (Cc) and a series resistor (Rs) can help prevent oscillations. The values of Cc and Rs depend on the specific application and can be determined through simulation or experimentation.
The LM1875T/LB03 has a maximum junction temperature of 150°C. To ensure reliable operation, it's essential to provide adequate heat sinking, especially in high-power applications. A thermal pad or heat sink can be used to dissipate heat, and the device should be operated within the recommended temperature range to prevent thermal shutdown.
LM1875T/LB03 datasheet
by Texas Instruments
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