Proper Power-Supply Jumper Settings for Evaluating the MAX9259/MAX9260 SerDes Chipset
Normally, the jumper settings mostly affect the functionality of the chipset. However, a combination of improper jumper settings can also damage the MAX9259EVKIT and MAX9260EVKIT. For example, the MAX9259EVKIT's JU9 position 2-3 and shunt installed on JU10 can damage the inductor L101 when powered up with a USB connector. To avoid this type of damage, verify jumper settings before powering on the MAX9259EVKIT/MAX9260EVKIT.
Table 1 describes the five most commonly used jumper configurations of MAX9259EVKIT JU9-JU10 and MAX9260EVKIT JU10-JU11 settings. The table provides the various power-supply options, so designers can use requirements specific to their design.
Table 1. Five Most Commonly Used Jumper Configurations
|Configuration||Power Supply||Shunt Position|
|1||Both EV kits powered by MAX9259EVKIT USB connector||Installed||1–2||1–2||Installed|
|2||Both EV kits powered by MAX9260EVKIT USB connector||Open||1–2||1–2||Installed|
|3||MAX9259EVKIT powered by USB connector; MAX9260EVKIT powered by external power supplies||Installed||1–2||Open||Open|
|4||MAX9259EVKIT powered by external power supplies; MAX9260EVKIT powered by USB connector||Open||Open||1–2||Installed|
|5||Both EV kits powered by external power supplies||Open||2–3||2–3||Open|
The power-supply portion of MAX9259EVKIT schematic is shown in Figure 1 and the MAX9260 power-supply portion is shown in Figure 2.
Figure 1. Power-supply portion of MAX9259EVKIT schematic.
Figure 2. Power-supply portion of MAX9260EVKIT schematic.
The microcontroller that initializes audio peripherals like the S/PDIF-to-I²S converter and the audio digital-to-analog converter (DAC) on the EV kit is powered with USB+5V. Therefore special attention is needed to evaluate the MAX9259/MAX9260 with the audio I²S function, which is achieved by using jumper configurations 3 to 5 of Table 1. USB+5V needs an external 5V power supply to power up the microcontroller.