Recommended operating conditions

The operating conditions are the physical parameters that the chip can operate within.

Table 1. Recommended operating conditions
Symbol Parameter Min. Nom. Max. Units
VDD VDD supply voltage, independent of DCDC enable 1.7 3.0 3.6 V
VDDPOR VDD supply voltage needed during power-on reset 1.75 V
VDDH VDDH supply voltage, independent of DCDC enable 2.5 3.7 5.5 V
VBUS VBUS USB supply voltage 4.35 5.0 5.5 V
tR_VDD Supply rise time (0 V to 1.7 V) 60 ms
tR_VDDH Supply rise time (0 V to 3.7 V)     100 ms
TA Operating temperature -40 25 85 °C
TJ Junction temperature     90 °C
Note: The on-chip power-on reset circuitry may not function properly for rise times longer than the specified maximum.

WLCSP light sensitivity

All WLCSP package variants are sensitive to visible and close-range infrared light. This means that a final product design must shield the chip properly, either by final product encapsulation or by shielding/coating of the WLCSP device.

Some WLCSP package variants have a backside coating, where the marking side of the device is covered with a light absorbing film, while the side edges and the ball side of the device are still exposed and need to be protected. Other WLCSP package variants do not have any such protection.

The WLCSP package variant CKAA has a backside coating.