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TPS3820, TPS3823, TPS3823A, TPS3824, TPS3825, TPS3828
SLVS165L – APRIL 1998 – REVISED JANUARY 2018
TPS382x Voltage Monitor With Watchdog Timer
1 Features
•1 Power-On Reset Generator With Fixed Delay Time of 200 ms (TPS3823/4/5/8) or 25 ms (TPS3820)
• Manual Reset Input (TPS3820/3/5/8) • Reset Output Available in Active-Low
(TPS3820/3/4/5), Active-High (TPS3824/5), and Open Drain (TPS3828) • Supply Voltage Supervision Range: 2.5 V, 3 V, 3.3 V, 5 V • Watchdog Timer (TPS3820/3/4/8) • Supply Current of 15 μA (Typical) • 5-Pin SOT-23 Package • Temperature Range: −40°C to 85°C
2 Applications
• DSPs, Microcontrollers, or Microprocessors • Industrial Equipment • Programmable Controls • Automotive Systems • Portable and Battery-Powered Equipment • Intelligent Instruments • Wireless Communications Systems • Notebook and Desktop Computers
3 Description
The TPS382x family of supervisors provide circuit
initialization and timing supervision, primarily for DSP
and processor-based systems. During power on,
RESET asserts when the supply voltage VDD becomes greater than 1.1 V. Thereafter, the supply
voltage supervisor monitors VDD and keeps RESET active low as long as VDD remains less than the threshold voltage, VIT−. An internal timer delays the return of the output to the inactive state (high) to
ensure proper system reset. The delay time, td, starts after VDD has risen above the threshold voltage (VIT− + VHYS). When the supply voltage drops below the threshold voltage VIT−, the output becomes active (low) again. No external components are required. All
the devices of this family have a fixed-sense
threshold voltage, VIT–, set by an internal voltage divider. The TPS382x family also offers watchdog
time out options of 200 ms (TPS3820) and 1.6 s
(TPS3823/4/8).
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS382x
SOT-23 (5)
2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at the end of the data sheet.
Typical Application Schematic
3.3 V
Normalized Input Threshold Voltage vs Free-Air Temperature
VDD RESET
TPS3823-33 MR WDI
GND
100 nF
VDD RESET
MSP430C325 I/O
GND
1.001 1
0.999 0.998 0.997
Normalized Input Threshold Voltage −V IT(TA), VIT(25°C)
0.996
0.995 −40
−15 10
35 60
TA − Free-Air Temperature − °C
85
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. PRODUCTION DATA.
TPS3820, TPS3823, TPS3823A, TPS3824, TPS3825, TPS3828
SLVS165L – APRIL 1998 – REVISED JANUARY 2018
www.ti.com
Table of Contents
1 Features .................................................................. 1 2 Applications ........................................................... 1 3 Description ............................................................. 1 4 Revision History..................................................... 2 5 Device Comparison Table..................................... 4 6 Pin Configuration and Functions ......................... 4 7 Specifications......................................................... 5
7.1 Absolute Maximum Ratings ...................................... 5 7.2 ESD Ratings ............................................................ 5 7.3 Recommended Operating Conditions....................... 5 7.4 Thermal Information .................................................. 5 7.5 Electrical Characteristics........................................... 6 7.6 Timing Requirements ................................................ 7 7.7 Switching Characteristics .......................................... 7 7.8 Typical Characteristics .............................................. 8 8 Detailed Description ............................................ 10 8.1 Overview ................................................................. 10 8.2 Functional Block Diagram ....................................... 10
8.3 Feature Description................................................. 10 8.4 Device Functional Modes........................................ 11 9 Application and Implementation ........................ 12 9.1 Application Information............................................ 12 9.2 Typical Applications ................................................ 12 10 Power Supply Recommendations ..................... 15 11 Layout................................................................... 15 11.1 Layout Guidelines ................................................. 15 11.2 Layout Example .................................................... 15 12 Device and Documentation Support ................. 16 12.1 Device Support...................................................... 16 12.2 Documentation Support ........................................ 16 12.3 Related Links ............