For all the applications, a 0.1 µF or higher value ceramic decoupling capacitor is recommended between IN terminal and GND. Use CIN ≥ 1 µF for automotive transient protection. See Transient Protection.
The optimum placement of decoupling capacitor is closest to the IN and GND terminals of the device. Care must be taken to minimize the loop area formed by the bypass-capacitor connection, the IN terminal, and the GND terminal of the device. See Figure 47 for PCB layout example with HTSSOP package.
High current carrying power path connections must be as short as possible and must be sized to carry atleast twice the full-load current.
RTN, which is the reference ground for the device must be a copper plane or island.
Locate all the device support components R(ILIM), C(dVdT), R(IMON), and MODE, UVLO, OVP resistors close to their connection pin. Connect the other end of the component to the RTN with shortest trace length.
The trace routing for the RILIM and R(IMON) components to the device must be as short as possible to reduce parasitic effects on the current limit and current monitoring accuracy. These traces must not have any coupling to switching signals on the board.
Protection devices such as TVS, snubbers, capacitors, or diodes must be placed physically close to the device they are intended to protect, and routed with short traces to reduce inductance. For example, a protection Schottky diode is recommended to address negative transients due to switching of inductive loads, and it must be physically close to the OUT and GND pins.
Thermal Considerations: When properly mounted, the PowerPAD package provides significantly greater cooling ability. To operate at rated power, the PowerPAD must be soldered directly to the board RTN plane directly under the device. Other planes, such as the bottom side of the circuit board can be used to increase heat sinking in higher current applications. Designs that do not need reverse input polarity protection can have RTN, GND and PowerPAD connected together. PowerPAD in these designs can be connected to the PCB ground plane.