Specifications
| Type | Description |
|---|---|
| Part Number | TPS3431 |
| Manufacturer | Texas Instruments |
| Product Type | LDO Regulator |
| Category | Power Management |
| Component Type | Power_IC |
| Package / Case | DRB VSON-8, 3.00 mm x 3.00 mm |
| Watchdog Timeout Accuracy | ±2.5% typical; at 25°C |
| Input Voltage Range | 1.8 V to 6.5 V; VDD operating range |
| Quiescent Current | 10 µA typical; IDD |
| Output Type | Active-low open-drain; WDO watchdog output |
| Operating Junction Temperature Range | -40°C to +125°C; recommended operating range |
| Supply Voltage Absolute Maximum | -0.3 V to 7 V; VDD, over operating free-air temperature range |
| Output Voltage Absolute Maximum | -0.3 V to 7 V; ENOUT, WDO |
| Input Voltage Absolute Maximum | -0.3 V to 7 V; SET1, WDI, EN |
| CWD Voltage Absolute Maximum | -0.3 V to VDD + 0.3 V; maximum is VDD + 0.3 V or 7.0 V, whichever is smaller |
| Output Pin Current Absolute Maximum | ±20 mA; ENOUT, WDO |
| Input Current Absolute Maximum | ±20 mA; all pins |
| Operating Junction Temperature Absolute Maximum | -40°C to +150°C; TJ |
| Operating Free-Air Temperature Absolute Maximum | -40°C to +150°C; TA |
| Storage Temperature Range | -65°C to +150°C; Tstg |
| HBM ESD Rating | ±4000 V; per ANSI/ESDA/JEDEC JS-001 |
| CDM ESD Rating | ±1000 V; per JEDEC JESD22-C101 |
| Recommended Supply Voltage | 1.8 V min, 6.5 V max; VDD |
| SET1 Pin Voltage | 0 V min, 6.5 V max; recommended operating condition |
| Watchdog Timing Capacitor | 0.1 nF min, 1000 nF max; 0.1 nF gives tWDU(typ) = 62.74 ms, 1000 nF gives tWDU(typ) = 77.45 s |
| CWD Pullup Resistor | 9 kΩ min, 10 kΩ nominal, 11 kΩ max; pullup resistor to VDD |
| ENOUT and WDO Pullup Resistor | 1 kΩ min, 10 kΩ nominal, 100 kΩ max; RPU |
| EN Pin Current | 10 mA max; IEN recommended operating condition |
| Watchdog Output Current | 10 mA max; IWDO recommended operating condition |
| Recommended Junction Temperature | -40°C min, +125°C max; TJ |
| Junction-to-Ambient Thermal Resistance | 50.7°C/W; DRB VSON, 8 pins |
| Junction-to-Case Top Thermal Resistance | 51.6°C/W; DRB VSON, 8 pins |
| Junction-to-Board Thermal Resistance | 25.8°C/W; DRB VSON, 8 pins |
| Junction-to-Top Characterization Parameter | 1.3°C/W; DRB VSON, 8 pins |
| Junction-to-Board Characterization Parameter | 25.8°C/W; DRB VSON, 8 pins |
| Junction-to-Case Bottom Thermal Resistance | 7.1°C/W; DRB VSON, 8 pins |
| Supply Current | 10 µA typ, 19 µA max; 1.8 V <= VDD <= 6.5 V, -40°C <= TJ <= +125°C, open-drain pullups 10 kΩ, typical at TJ = 25°C |
| Power-On Reset Voltage | 0.8 V typ; VPOR, VOL(max) = 0.25 V |
| EN Internal Pullup Current | 500 nA min, 620 nA typ, 700 nA max; VEN = 0 V |
| CWD Pin Charge Current | 347 nA min, 375 nA typ, 403 nA max; CWD = 0.5 V |
| CWD Pin Threshold Voltage | 1.196 V min, 1.21 V typ, 1.224 V max; 1.8 V <= VDD <= 6.5 V, -40°C <= TJ <= +125°C |
| Output Low Voltage | 0.4 V max; ENOUT, WDO; VDD = 5 V, ISINK = 3 mA |
| Output Leakage Current | 1 µA max; ENOUT, WDO; VDD = 1.8 V, VWDO = 6.5 V |
| Low-Level Input Voltage | 0.25 V max; EN, SET1 |
| High-Level Input Voltage | 0.8 V min; EN, SET1 |
| WDI Low-Level Input Voltage | 0.3 x VDD max; WDI |
| WDI High-Level Input Voltage | 0.8 x VDD min; WDI |
| CWD Pin Evaluation Period | 381 µs typ; tINIT |
| EN and SET1 Pin Setup Time | 1 µs typ; timing requirement |
| Startup Delay | 300 µs typ; during power-on, VDD must be at least 1.8 V before WDI is active and ENOUT is high impedance |
| EN to ENOUT Delay | 200 ns typ; tEN_ENOUT |
| Watchdog Reset Delay | 170 ms min, 200 ms typ, 230 ms max; tRST |
| Watchdog Timeout | 1360 ms min, 1600 ms typ, 1840 ms max; CWD = NC, SET1 = 1 |
| Watchdog Timeout | 170 ms min, 200 ms typ, 230 ms max; CWD = 10 kΩ to VDD, SET1 = 1 |
| Watchdog Disabled State | Watchdog disabled; CWD = NC, SET1 = 0 |
| Watchdog Disabled State | Watchdog disabled; CWD = 10 kΩ to VDD, SET1 = 0 |
| WDI Response Setup Time After Enable | 150 µs typ; tWD-setup, setup time required for device to respond to changes on WDI after being enabled |
| Minimum WDI Pulse Duration | 50 ns typ; WDI input pulse |
| WDI to WDO Delay | 50 ns typ; tWD-del |
| VDD Pin Function | Supply voltage pin; 0.1 µF bypass capacitor recommended for noisy systems; pin 1 |
| CWD Pin Function | Sets watchdog timeout with capacitor to ground or selects preset timeouts when connected through 10 kΩ to VDD or left unconnected; pin 2 |
| EN Pin Function | Internally pulled up to VDD; logic low drives ENOUT low, ignores WDI, and keeps WDO logic high; pin 3 |
| SET1 Pin Function | Grounding SET1 disables watchdog timer; pin 5 |
| WDI Pin Function | Falling edge must occur before watchdog timeout expires; pin 6 |
| WDO Pin Function | Open-drain active-low output asserts low when watchdog timeout occurs for tRST; pin 7, use 1 kΩ to 100 kΩ pullup resistor |
| ENOUT Pin Function | Open-drain active-high enable output asserts after tRST when EN goes logic high; pin 8, use 1 kΩ to 100 kΩ pullup resistor |
| Datasheet Status | request_only |
Product Overview
The TPS3431 is a Texas Instruments programmable watchdog timer for Power_Management designs requiring monitored WDI activity and an active-low open-drain watchdog output. The device operates across a 1.8 V to 6.5 V VDD range and uses a WDO output that asserts low when the watchdog timeout occurs for the reset interval.
Timing is configured through the CWD and SET1 pins. The CWD pin can set watchdog timeout with a capacitor to ground, or select preset timeouts when connected through 10 kΩ to VDD or left unconnected. Grounding SET1 disables the watchdog timer. Extracted timing parameters include a 200 ms typical watchdog reset delay, 1600 ms typical timeout with CWD not connected and SET1 high, and 200 ms typical timeout with CWD tied to VDD through 10 kΩ and SET1 high.
The device is offered in a DRB VSON-8, 3.00 mm x 3.00 mm package. Pin-level implementation details include a recommended 0.1 µF VDD bypass capacitor for noisy systems, 1 kΩ to 100 kΩ pullup resistors on WDO and ENOUT, and a 9 kΩ to 11 kΩ CWD pullup resistor when used.
Key Features
- Programmable watchdog timer in DRB VSON-8 package
- 1.8 V to 6.5 V VDD operating range
- 10 µA typical quiescent current rating
- ±2.5% typical watchdog timeout accuracy at 25°C
- Active-low open-drain WDO watchdog output
- Capacitor-programmed or preset CWD watchdog timing
- SET1 grounding disables the watchdog timer
- 170 ms to 230 ms watchdog reset delay
- -40°C to +125°C recommended junction operation
- 1 kΩ to 100 kΩ WDO and ENOUT pullups
Typical Applications
- Watchdog timer circuits
- Power-management monitoring
- Enable-output sequencing
- WDI activity supervision
- Capacitor-programmed timeout designs
- Preset watchdog timeout designs
- Open-drain reset signaling
- Noisy supply systems
Procurement Notes
When requesting a quote for TPS3431, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.
If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.
For power IC and power device sourcing, voltage rating, current rating, power dissipation, package thermal performance, protection features, qualification grade and application conditions should be reviewed before approval.
FAQ
What supply voltage range does the TPS3431 support?
The TPS3431 operates from a 1.8 V to 6.5 V VDD range. The same 1.8 V minimum and 6.5 V maximum are listed as the recommended supply-voltage operating condition.
How is the TPS3431 watchdog timeout configured?
The CWD pin sets the watchdog timeout with a capacitor to ground, or selects preset timeouts when connected through 10 kΩ to VDD or left unconnected. Grounding SET1 disables the watchdog timer.
What type of watchdog output does the TPS3431 provide?
The WDO watchdog output is active-low and open-drain. It asserts low when a watchdog timeout occurs for tRST, and the pin function specifies use of a 1 kΩ to 100 kΩ pullup resistor.
What package is specified for the TPS3431?
The TPS3431 package case is DRB VSON-8, measuring 3.00 mm x 3.00 mm. The listed thermal data applies to the DRB VSON package with 8 pins.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: July 7, 2026.
This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.