UC-00-M32 EN R1.0
Hardware Design
15
3.2
Grounding and Heat Dissipation
Figure 3-2 Grounding and Heat Dissipation Pad
The 48 pads in the rectangle in Figure 3-2 are for grounding and heat dissipation. In the
PCB design, it is recommended to connect them to a large sized ground to strengthen
the heat dissipation.
3.3
Power-on and Power-off
VCC
The VCC initial level when power-on should be less than 0.4 V and has good
monotonicity. The voltages of undershoot and ringing should be within 5% VCC.
VCC power-on waveform: The time interval from 10% rising to 90% must be within 100
us ~1 ms.
Power-on time interval: The time interval between the VCC < 0.4 V (after power-off) to
the next power-on must be larger than 500 ms.
V_BCKP
The V_BCKP initial level when power-on should be less than 0.4 V and has good
monotonicity. The voltages of undershoot and ringing should be within 5% V_BCKP.
V_BCKP power-on waveform: The time interval from 10% rising to 90% must be within
100 us ~1 ms.
Power-on time interval: The time interval between the V_BCKP < 0.4 V (after power-off)
to the next power-on must be larger than 500 ms.
Grounding and
heat dissipation pad
