Datasheet

Device description PM6641
34/47 Doc ID 13510 Rev 3
7.11.3 Thermal shutdown
If the device temperature exceeds 150 °C, a thermal protection is triggered. As a
consequence, the output soft end takes place for all the outputs of the PM6641 (VDDQ rail
(1.8 V), VTT, VTTREF, 1.5 V, 1.05 V) by closing the output discharge MOSFET (see
Chapter 7.7: Outputs soft-end on page 29 section for details).
The thermal protection condition is not latched: the device leaves this condition and
reactivates itself automatically when its temperature falls below 135 °C (i.e. there is a 15 °C
of hysteresis).
7.11.4 Input under voltage lock-out
The PM6641 AVCC pin is the device power supply input. This pin must be fed with 5 V,
±10% in order to allow the device to work properly. If this rail falls under 3.9 V typical
threshold, the input under voltage is detected and the device performs the under voltage
lock-out (UVLO) protection. When this event occurs, each regulator stops switching and the
following actions are performed:
● The memory supply rails (VDDQ, VTT and VTTREF) are discharged by closing the
output discharge MOSFET (see
Chapter 7.7: Outputs soft-end on page 29 section for
details);
● Chipset power supply output rails (1V5 and 1V05 rails) are discharged through the low
side power MOSFETs;
● The device is turned OFF.
The PM6641 is turned on again when the AVCC pin voltage reaches the UVLO on threshold
(about 4.1 V).