Datasheet
DLY1 DLY2 DLY3 DLY4
STROBE 1
SEQ = 0001
STROBE 2
SEQ = 0010
STROBE 3
SEQ = 0011
STROBE 4
SEQ = 0100
STROBE 5
SEQ = 0101
STROBE15
SEQ = 1111
STROBE14
SEQ = 1110
DLY6
PWR_EN
(input)
DLY5
STROBE 6
SEQ = 0110
DLY6
STROBE 7
SEQ = 0111
nWAKEUP
(output)
PB
(input)
USB
(input)
AC
(input)
5s max
TPS65217A, TPS65217B, TPS65217C, TPS65217D
www.ti.com
SLVSB64F –NOVEMBER 2011–REVISED APRIL 2013
WAKE-UP AND POWER UP SEQUENCING
The TPS65217 has a pre-defined power-up / power-down sequence which in a typical application does not need
to be changed. However, it is possible to define custom sequences under I
2
C control. The power-up sequence is
defined by strobes and delay times. Each output rail is assigned to a strobe to determine the order in which the
rails are enabled and the delay times between strobes are selectable in a range from 1 ms to 10 ms.
NOTE
Although the user can modify the power-up and power-down sequence through the SEQx
registers, those registers are reset to default values when the device enters SLEEP, OFF
or RESET state. In practice this means that the power-up sequence is fixed and a other-
than-default power-down sequence has to be written every time the device is powered up.
Custom power-up/down sequences can be checked out in ACTIVE mode (PWR_EN pin
high) by using the SEQUP and SEQDWN bits. To change the power-up default values,
please contact the factory.
Power-Up Sequencing
When the main power-up sequence is initiated, STROBE1 occurs and any rail assigned to this strobe will be
enabled. After a delay time of DLY1 STROBE2 occurs and the rail assigned to this strobe is powered up. The
sequence continues until all strobes have occurred and all DLYx times have been executed.
Figure 2. Power-Up Sequence is Defined by Strobes and Delay Times. In This Example Push-Button Low
is the Power-Up Event.
The default power-up sequence can be changed by writing to the SEQ1-6 registers. Strobes are assigned to rails
by writing to the SEQ1-4 registers. A rail can be assigned to only one strobe but multiple rails can be assigned to
the same strobe. Delays between strobes are defined in registers SEQ5 and SEQ6.
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Product Folder Links: TPS65217A TPS65217B TPS65217C TPS65217D