Features: * Minimum Supply Voltage of 0.75 V
* Supply Voltage Supervision Range:
-1.2 V, 1.5 V, 1.8 V (TPS312x)
-3 V (TPS3125 Devices Only)
-Other Versions on Request
* Power-On Reset Generator With Fixed Delay Time of 180 ms
* Manual Reset Input (TPS3123/5/6/8)
* Watchdog Timer Retriggers the RESET Output at VDD VIT
* Supply Current of 14 A (Typ)
* Small SOT23-5 Package
* Temperature Rangeof -40 to 85
* Reset Output Available in Push-Pull (Active Low and High) and Open-Drain (Active-Low)Application* Applications Using Low Voltage DSPs,Microcontrollers, or Microprocessors
* Portable/Battery-Powered Equipment
* Wireless Communication Systems
* Programmable Controls
* Industrial Equipment
* Notebook/Desktop Computers
* Intelligent InstrumentsPinout
Specifications
| |
UNIT |
| Manual reset, MR |
-0.3 V to VDD + 0.6 V |
| Supply voltage, VDD |
3.6 V |
| Watchdog input, WDI |
-0.3 V to VDD + 6 V |
| Maximum low output current, IOL |
5 mA |
| Maximum high output current, IOH |
-5 mA |
| Input clamp current, IIK (VI< 0 or VI > VDD ) |
±10 mA |
Output clamp current, IOK (VO < 0 or VO > VDD)
|
±10 mA
|
| Continuous total power dissipation |
See Dissipation Rating Table |
| Operating free-air temperature range, TA |
-40 to 85 |
| Storage temperature range, Tstg |
-65 to 150
|
| Soldering temperature |
260 |
DescriptionThe TPS312x family of ultralow voltage processor supervisory circuits provides circuit initialization and timing supervision, primarily for DSP and processor-based systems.
During power-on, RESET is asserted when the supply voltage (VDD) becomes higher than 0.75 V. Thereafter, the supply voltage supervisor monitors VDD and keeps RESET output active as long as VDD remains below 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 = 180 ms, starts after VDD has risen above the threshold voltage (VIT).When the supply voltage drops below the threshold voltage (VIT ), the output becomes active (low) again. No external components are required. All the TPS312x devices of this family have a fixed-sense threshold voltage (VIT ) set by a high precision internal voltage divider.
In the TPS312x , the TPS3123/5/6/8 devices incorporate a manual reset input, MR. A low level at MR causes RESET to become active. The TPS3124 devices do not have the input MR, but include a high-level output RESET same as the TPS3125 and TPS3126 devices. In addition, the TPS3123/4/8 have a watchdog timer that needs to be triggered periodically by a positive or negative transition at WDI. When the supervising system fails to retrigger the watchdog circuit within the time-out interval ttout = 0.8 s, RESET output becomes active for the time period (td). This event also reinitializes the watchdog timer.
The TPS312x circuits are available in a 5-pin SOT23-5 package. The TPS312x devices are characterized for operation over a temperature range of -40 to 85.
TPS3128 Data Sheet
