TPS3813I50-Q1 Datasheet, PDF (1/16 Pages) Texas Instruments – PROCESSOR SUPERVISORY CIRCUITS WITH WINDOW-WATCHDOG

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TPS3813J25-Q1, TPS3813L30-Q1
TPS3813K33-Q1, TPS3813I50-Q1
SPRS288B – MAY 2008 – REVISED APRIL 2012
PROCESSOR SUPERVISORY CIRCUITS WITH WINDOW-WATCHDOG
Check for Samples: TPS3813J25-Q1, TPS3813L30-Q1, TPS3813K33-Q1, TPS3813I50-Q1
FEATURES
1
•2 Qualified for Automotive Applications
• 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
• Temperature Range –40°C to 125°C
APPLICATIONS
• Applications Using DSPs, Microcontrollers, or
Microprocessors
• Safety-Critical Systems
• Automotive Systems
• Heating Systems
DESCRIPTION
The TPS3813 supervisory circuits provide circuit
initialization and timing supervision, primarily for
DSPs and processor-based systems.
During power on, RESET is asserted when supply
voltage (V_DD) becomes higher than 1.1 V. Thereafter,
the supervisory circuit monitors V_DD and keeps
RESET 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 state (high) to
ensure proper system reset. The delay time, t_d = 25
ms typical, starts 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 family
incorporates a window-watchdog with programmable
delay and window ratio. The upper limit of the
watchdog time-out can be set by either connecting
WDT to GND or V_DD, or by using an external
capacitor. The lower limit, and thus the window ratio,
is set by connecting WDR to GND or V_DD. The
supervised processor now needs to trigger the
TPS3813 within this window not to assert a RESET.
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 a 6-pin SOT-23 package.
The TPS3813 devices are characterized for operation
over a temperature range of –40°C to 125°C.
V_DD
0.1mF
R
0.1mF
V_DD
WDR
RESET
TPS3813
WDT
WDI
C_WP
GND
V_DD
RESET
mC
I/O
GND
DBV PACKAGE
SOT-23
(TOP VIEW)
WDI
1
6
RESET
GND
2
5
WDR
WDT
3
4
V_DD
Typical Operating Circuit
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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