SI86XX Datasheet, PDF (30/52 Pages) Silicon Laboratories – No start-up initialization required

Si86xx
3. Device Operation
Device behavior during start-up, normal operation, and shutdown is shown in Figure 9, where UVLO+ and UVLO-
are the positive-going and negative-going thresholds respectively. Refer to Table 12 to determine outputs when
power supply (VDD) is not present. Additionally, refer to Table 13 for logic conditions when enable pins are used.
Table 12. Si86xx Logic Operation
V_I
EN
VDDI
VDDO _{VO Output}^1,2
Input^{1,2 Input1,2,3,4 State1,5,6 State1,5,6}
Comments
H
H or NC
P
P
H
Enabled, normal operation.
L
H or NC
P
X⁷
L
P
X⁷
H or NC
UP
X⁷
L
UP
X⁷
X⁷
P
P
L
P
Hi-Z⁸
Disabled.
P
Upon transition of VDDI from unpowered to pow-
L
ered, V_O returns to the same state as V_I in less
than 1 µs.
P
Hi-Z⁸
Disabled.
UP Undetermined Upon transition of VDDO from unpowered to pow-
ered, V_O returns to the same state as V_I within
1 µs, if EN is in either the H or NC state. Upon tran-
sition of VDDO from unpowered to powered, V_O
returns to Hi-Z within 1 µs if EN is L.
Notes:
1. VDDI and VDDO are the input and output power supplies. V_I and V_O are the respective input and output terminals. EN
is the enable control input located on the same output side.
2. X = not applicable; H = Logic High; L = Logic Low; Hi-Z = High Impedance.
3. It is recommended that the enable inputs be connected to an external logic high or low level when the Si86xx is
operating in noisy environments.
4. No Connect (NC) replaces EN1 on some devices. No Connects are not internally connected and can be left floating,
tied to VDD, or tied to GND.
5. “Powered” state (P) is defined as 2.5 V < VDD < 5.5 V.
6. “Unpowered” state (UP) is defined as VDD = 0 V.
7. Note that an I/O can power the die for a given side through an internal diode if its source has adequate current.
8. When using the enable pin (EN) function, the output pin state is driven into a high-impedance state when the EN pin is
disabled (EN = 0).
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Rev. 1.0