9.2.2 Detailed Design Procedure

The LP503x device scales up the reference current (I_REF) set by the external resistor (R_IREF) to sink the output current (I_OUT) at each output port. can be used to calculate the target output current I_{MAX_SET}:

The SCL and SDA lines must each have a pullup resistor placed somewhere on the line (the pullup resistors are normally located on the bus master). In typical applications, values of 1.8 kΩ to 4.7 kΩ are used, depending on the bus capacitance, I/O voltage, and the desired communication speed. Selecting a smaller value increases the pullup speed, but slows the pulldown speed. If they want pull up quickly select the samller one but it will impact the pull down speed.

VCAP is the internal LDO output pin. This pin must be connected through a 1-μF capacitor to GND. Put the capacitor as close to the device as possible.

TI recommends having a 1-μF capacitor between VCC and GND to ensure proper operation. Put the capacitor as close to the device as possible.