SI8421AD Datasheet, PDF (23/37 Pages) List of Unclassifed Manufacturers – LOW-POWER, SINGLE AND DUAL-CHANNEL DIGITAL ISOLATORS

Si8410/20/21 (5 kV)
Si8422/23 (2.5 & 5 kV)
3.1. Device Startup
Outputs are held low during powerup until V_DD is above the UVLO threshold for time period tSTART. Following this,
the outputs follow the states of inputs.
3.2. Under Voltage Lockout
Under Voltage Lockout (UVLO) is provided to prevent erroneous operation during device startup and shutdown or
when V_DD is below its specified operating circuits range. Both Side A and Side B each have their own undervoltage
lockout monitors. Each side can enter or exit UVLO independently. For example, Side A unconditionally enters
UVLO when V_DD1 falls below V_{DD1(UVLO–)} and exits UVLO when V_DD1 rises above V_DD1(UVLO+). Side B operates
the same as Side A with respect to its V_DD2 supply.
UVLO+
UVLO-
V_DD1
UVLO+
UVLO-
V_DD2
INPUT
tSTART
OUTPUT
tSD
tSTART
tSTART
tPHL tPLH
Figure 7. Device Behavior during Normal Operation
Rev. 1.3
23