TPS3813K33-Q1 Datasheet, PDF (1/21 Pages) Texas Instruments – Processor Supervisory Circuits With Window-Watchdog

Product
Folder
Sample &
Buy
Technical
Documents
Tools &
Software
Support &
Community
TPS3813K33-Q1, TPS3813I50-Q1
SPRS288D – MAY 2008 – REVISED JUNE 2015
TPS3813-Q1 Processor Supervisory Circuits With Window-Watchdog
1 Features
•1 Qualified for Automotive Applications
• AEC-Q100 Qualified With the Following Results:
– Device Temperature Grade 1: –40°C to 125°C
Ambient Operating Temperature Range
– Device HBM Classification Level 2
– Device CDM Classification Level C4B
• Window-Watchdog With Programmable Delay and
Window Ratio
• 6-Pin SOT-23 Package
• Supply Current of 9 μA (Typ)
• Power-On Reset Generator With a Fixed Delay
Time of 25 ms
• Precision Supply-Voltage Monitor:
2.5 V, 3 V, 3.3 V, 5 V
• Open-Drain Reset Output
2 Applications
• Applications Using DSPs, Microcontrollers, or
Microprocessors
• Safety-Critical Systems
• Automotive Systems
• Heating Systems
3 Description
The TPS3813-Q1 supervisory circuits provide circuit
initialization and timing supervision, primarily for
DSPs and processor-based systems.
During power on, the RESET pin is asserted when
the supply voltage (V_DD) becomes higher than 1.1 V.
Thereafter, the supervisory circuit monitors V_DD and
keeps the RESET pin active as long as V_DD remains
below the threshold voltage (V_IT).
An internal timer delays the return of the output to the
inactive (high) state to ensure proper system reset.
The delay time, t_d = 25 ms typical, begins after V_DD
has risen above the threshold voltage (V_IT). When the
supply voltage drops below the threshold voltage
(V_IT), the output becomes active (low) again. No
external components are required. All the devices of
this family have a fixed-sense threshold voltage (V_IT)
set by an internal voltage divider.
For safety-critical applications, the TPS3813-Q1
family of devices incorporate a window-watchdog with
programmable delay and window ratio. The upper
limit of the watchdog time-out can be set by either
connecting the WDT pin to GND or V_DD, or by using
an external capacitor. The lower limit, and thus the
window ratio, is set by connecting the WDR pin to
GND or V_DD. The RESET pin will assert a reset to the
microcontroller if the watchdog is incorrectly serviced.
The product spectrum is designed for supply voltages
of 2.5 V, 3 V, 3.3 V, and 5 V. The devices are
available in a 6-pin SOT-23 package. The devices
are characterized for operation over a temperature
range of –40°C to 125°C.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS3813K33-Q1
TPS3813I50-Q1
SOT-23 (6)
2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Operating Circuit
V_DD
0.1 µF
R
0.1 µF
V_DD
WDR
RESET
TPS3813xxx-Q1
WDT
WDI
C_WP
GND
V_DD
RESET
µC
I/O
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. UNLESS OTHERWISE NOTED, this document contains PRODUCTION
DATA.