Silicon Laboratories Si8410, Manual, Page: 22 / 38

S i 8 4 1 0 / 2 0 / 2 1 ( 5 k V )
S i 8 4 2 2 / 2 3 ( 2 . 5 & 5 k V )
22 Rev. 1.1
3. Device Operation
Device behavior during start-up, normal operation, and shutdown is shown in Figure 7, where UVLO+ and UVLO-
are the positive-going and negative-going thresholds respectively. Refer to Table 12 to determine outputs when
power supply (
V
DD
) is not present.
Table 12. Si84xx Logic Operation Table
V
I
Input
1, 4
VDDI State
1,2,3
VDDO State
1,2,3
V
O
Output
1, 4 Comments
H P P H
Normal operation.
L P P L
X
5
UP P H
6
(Si8422/23)
L
6
(Si8410/20/21)
Upon transition of VDDI from unpowered to
powered, V
O
returns to the same state as V
I
in
less than 1 µs.
X
5
P UP Undetermined Upon transition of VDDO from unpowered to
powered, V
O
returns to the same state as V
I
within 1 µs.
Notes:
1. VDDI and VDDO are the input and output power supplies. V
I
and V
O
are the respective input and output terminals.
2. Powered (P) state is defined as 2.70 V < VDD < 5.5 V.
3. Unpowered (UP) state is defined as VDD = 0 V.
4. X = not applicable; H = Logic High; L = Logic Low.
5. Note that an I/O can power the die for a given side through an internal diode if its source has adequate current.
6. See "6. Ordering Guide" on page 29 for details. This is the selectable fail-safe operating mode (ordering option). Some
devices have default output state = H, and some have default output state = L, depending on the ordering part number
(OPN).