A good PCB layout for the MAX4821EUP+ involves keeping the input and output traces short and away from each other, using a solid ground plane, and placing the input and output capacitors close to the IC. Additionally, it's recommended to use a shielded inductor and to keep the switching node (pin 5) away from sensitive analog nodes.
The inductor value depends on the input voltage, output voltage, and switching frequency. A good starting point is to use the inductor value recommended in the datasheet (e.g., 10uH). Then, adjust the value based on the specific application requirements, such as output current and ripple voltage. It's also important to consider the inductor's saturation current and DC resistance.
The maximum output current of the MAX4821EUP+ depends on the input voltage, output voltage, and inductor value. According to the datasheet, the maximum output current is 2A. However, this value can be derated based on the specific application requirements, such as ambient temperature and output voltage. It's recommended to consult the datasheet and perform thermal calculations to determine the maximum output current for a specific design.
The internal voltage reference of the MAX4821EUP+ has a tolerance of ±2%. To compensate for this tolerance, it's recommended to use an external voltage reference or to adjust the output voltage using a resistive divider network. Additionally, the output voltage can be trimmed using an external trim pin (pin 6) to achieve a more accurate output voltage.
The EN (enable) pin is used to enable or disable the MAX4821EUP+. When the EN pin is high, the device is enabled, and when it's low, the device is disabled. This pin can be used to implement power sequencing, shutdown, or low-power modes in the system. It's recommended to connect the EN pin to a logic signal or a power-good signal to ensure proper device operation.
MAX4821EUP+ datasheet
by Maxim Integrated Products
