L DESIGN FEATURES MOSFETs Make Sense for Tracking
and Sequencing Power Supplies
by Thomas DiGiacomo
Introduction:
Charge MOSFETs with the
Task of Supply Control
In electronic systems with multiple
supplies, the need for tracking and/or
sequencing is well established. On the
one hand, core and I/O power might
be required to ramp up and down together with less than a diode’s voltage
drop between them to avoid potentially destructive latch-up. Coincident
tracking, as shown in Figure 1a, solves
this problem. On the other hand, in a
distributed supply chain, some supplies might need to be fully operational
before others. Supply sequencing,
as shown in Figure 1d, solves that
problem. Other systems may require
simultaneous completion of supply
ramps (Figure 1b), voltage offsets or
time delays (Figure 1c), or combinations of such profiles.
Linear’s line of no-MOSFET tracking
and sequencing control products, the …