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 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
TAEXT Extended operating temperature 85   105 °C
TJ Junction temperature     110 °C
Note: The on-chip power-on reset circuitry may not function properly for rise times longer than the specified maximum.

Extended Operating Temperature

The operating temperature range for the device is defined in Recommended operating conditions. The range extends from TA minimum to TAEXT maximum.

Some electrical parameters are valid only for the TA operating temperature conditions. When this is the case, an additional parameter for the TAEXT extended operating temperature condition is provided.

Note: When running the device in the extended operating temperature conditions range, the register LFXODEBOUNCE must be set to Extended.

To avoid surpassing the maximum die juntion temperature, see Recommended operating conditions, it is important to minimize current consumption when operating in the extended operating temperature conditions. To achieve this, it is recommended to use the device in Normal Voltage mode with DC/DC enabled. See POWER — Power supply for details about main supply modes.

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 CJAA has a backside coating.