Quick Detail:
PROCESSOR SUPERVISORY CIRCUITS WITH POWER-FAIL
Description:
The TPS3705, TPS3707 family of microprocessor supply-voltage
supervisors provide 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 1.1 V. Thereafter, the supply voltage
supervisor monitors VDD and keeps RESET 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, tdtyp= 200 ms, starts after
VDDhas 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
devices of this family have a fixed-sense threshold voltage VIT–
set by an internal voltage divider.
The TPS3705-xx and TPS3707-xx devices incorporate a manual reset
input, MR. A low level at MR causes RESET to become active.
The TPS370x-xx families integrate a power-fail comparator which can
be used for low-battery detection, power-fail warning, or for
monitoring a power supply other than the main supply.
The TPS3705-xx devices 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, tt(out)= 1.6 s, WDO becomes active. This
event also reinitializes the watchdog timer. Leaving WDI
unconnected disables the watchdog.
The TPS3707-xx devices do not have the Watchdog function, but
include a high-level output 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 either 8-pin MSOP or
standard SOIC packages. The TPS3705, TPS3707 devices are
characterized for operation over a temperature range of –40°C to
85°C.
Applications:
Power-On Reset Generator with Fixed Delay Time of 200 ms, no
External
Capacitor Needed
Precision Supply Voltage Monitor 2.5 V, 3 V, 3.3 V, and 5 V
Pin-For-Pin Compatible with the MAX705 through MAX708 Series
Integrated Watchdog Timer (TPS3705 only)
Voltage Monitor for Power-Fail or Low-Battery Warning
Maximum Supply Current of 50 µA
MSOP-8 and SO-8 Packages
Temperature Range . . . –40°C to 85°C
Specifications:
| Datasheets | TPS3705-xx, TPS3707-xx |
| Product Photos | 8-SOIC |
| Standard Package | 1 |
| Category | Integrated Circuits (ICs) |
| Family | PMIC - Supervisors |
| Series | - |
| Packaging | Digi-Reel® |
| Type | Simple Reset/Power-On Reset |
| Number of Voltages Monitored | 1 |
| Output | Push-Pull, Totem Pole |
| Reset | Active Low |
| Reset Timeout | 140 ms Minimum |
| Voltage - Threshold | 2.93V |
| Operating Temperature | -40°C ~ 85°C |
| Mounting Type | Surface Mount |
| Package / Case | 8-SOIC (0.154", 3.90mm Width) |
| Supplier Device Package | 8-SOIC |
| Other Names | 296-26940-6 |
