Datasheet

WDI
RESET
TPS3824
WDI External
TPS382x-xx
TPS382xA-xx
SLVS165J –APRIL 1998–REVISED APRIL 2013 www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION (CONTINUED)
The TPS3820/3/5/8 devices incorporate a manual reset input, MR. A low level at MR causes RESET to become
active. The TPS3824/5 devices include a high-level output RESET. TPS3820/3/4/8 have a watchdog timer that is
periodically triggered by a positive or negative transition at WDI. When the supervising system fails to retrigger
the watchdog circuit within the time-out interval, t
tout
, RESET becomes active for the time period t
d
. This event
also reinitializes the watchdog timer. Leaving WDI unconnected disables the watchdog. In applications where the
input to the WDI pin may be active (transitioning high and low) when the TPS3820/3/4/8 is asserting RESET, the
TPS3820/3/4/8 does not return to a non-reset state when the input voltage is above V
T
.
If the application requires that input to WDI is active when RESET pin is asserted, then the “A” version of the
device should be used. The “A” versions will not latch the RESET to the asserted state if a WDI pulse is received
while RESET is asserted.
Figure 1 shows how to decouple WDI from the active signal using when using the non−”A” version. This is
accomplished with an N−Channel FET in series with the WDI pin, with the gate of the FET connected to the
RESET output. The “A” version of the device does not need this FET but will operate in circuits that have it.
Therefore, the “A” version is backward compatible with the non’”A” versions.
Figure 1.
The product spectrum is designed for supply voltages of 2.5 V, 3 V, 3.3 V, and 5 V. The circuits are available in
an SOT23-5 package. The TPS382x devices are characterized for operation over a temperature range of −40°C
to 85°C.
PACKAGE INFORMATION
(1)
DEVICE NAME
(2)
DEVICE NAME
(3)
THRESHOLD VOLTAGE
(4)
MARKING
TPS3820-33DBVT TPS3820-33DBVR 2.93 V PDEI
TPS3820-50DBVT TPS3820-50DBVR 4.55 V PDDI
TPS3823-25DBVT TPS3823-25DBVR 2.25 V PAPI
TPS3823-30DBVT TPS3823-30DBVR 2.63 V PAQI
TPS3823-33DBVT TPS3823-33DBVR 2.93 V PARI
TPS3823-50DBVT TPS3823-50DBVR 4.55 V PASI
TPS3824-25DBVT TPS3824-25DBVR 2.25 V PATI
TPS3824-30DBVT TPS3824-30DBVR 2.63 V PAUI
TPS3824-33DBVT TPS3824-33DBVR 2.93 V PAVI
TPS3824-50DBVT TPS3824-50DBVR 4.55 V PAWI
TPS3825-33DBVT TPS3825-33DBVR 2.93 V PDGI
TPS3825-50DBVT TPS3825-50DBVR 4.55 V PDFI
TPS3828-33DBVT TPS3828-33DBVR 2.93 V PDII
TPS3828-50DBVT TPS3828-50DBVR 4.55 V PDHI
TPS3823A-33DBVT TPS3823A-33DBVR 2.93 V PYPI
(1) For the most current package and ordering information see the Package Option Addendum at the end
of this document, or see the TI web site at www.ti.com.
(2) The DBVT package indicates tape and reel of 250 parts.
(3) The DBVR package indicates tape and reel of 3000 parts.
(4) For other threshold voltage versions, please contact the local TI sales office.
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Product Folder Links: TPS382x-xx TPS382xA-xx