Datasheet

VTT VTT
VTTSS
VTTOCL
C V
t
I
´
=
VDDQ VDDQ
VDDQSS
VDDQOCP
2 C V 0.8
t 85 s
I
´ ´ ´
= + m
V
OCL
V
VDDQ
V
PGOOD
V
S5
80%
87%
100%
85 µs
45 µs
UDG−04066
TI Information — Selective Disclosure
TPS51116
SLUS609I –MAY 2004–REVISED JANUARY 2014 www.ti.com
Figure 2. VDDQ Soft-Start and Powergood Timing
Soft-start duration, t
VDDQSS
, t
VTTSS
are functions of output capacitances.
where
• I
VDDQOCP
is the current limit value for VDDQ switcher calculated by Equation 5 (2)
where
• I
VTTOCL
= 2.2 A (typ) (3)
In both Equation 2 and Equation 3 , no load current during start-up are assumed. Note that both switchers and
the LDO do not start up with full load condition.
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