TPS3431SQDRBRQ1 - Programmable Window Watchdog | TI
MPN: TPS3431SQDRBRQ1 ✓ ActiveTPS3431SQDRBRQ1 Overview
A watchdog timer is a supervisory circuit that monitors a system heartbeat and generates a fault response when the monitored timing behavior becomes invalid. A window watchdog adds upper and lower timing boundaries, allowing it to detect both a missing or late heartbeat and an unexpectedly early heartbeat. Within the broader hierarchy, this device is a timer, a supervisory circuit, a power-management IC, and a semiconductor.
The TPS3431SQDRBRQ1 supports two watchdog-timeout programming methods: an external capacitor or factory-programmed default delay settings. Its 15% timeout accuracy applies over the full -40°C to +125°C range, while its typical timing error is 2.5% at 25°C. The watchdog can be disabled through the enable pin or SET logic pins, helping prevent unwanted resets during firmware development, production testing, or controlled shutdown.
The device also provides open-drain, active-low fault signaling, based on the distributor specification. Its 8-pin VSON body is only 3.00 mm × 3.00 mm, making it suitable for compact automotive and industrial control assemblies. TI identifies the package as having wettable flanks for easier optical inspection after soldering, improving assembly-process visibility without changing the package footprint.
Typical applications include automotive electronic control units, battery-powered industrial controllers, motor-control modules, safety-monitoring subsystems, and embedded systems where a microcontroller or processor must service the watchdog within a defined timing window. The device is particularly appropriate when the design must distinguish an early or late heartbeat rather than relying only on a simple elapsed-time timeout.
When laying out the circuit, place the watchdog capacitor and timing-related components close to their associated pins, provide a stable supply and ground path, and route the open-drain reset output with suitable pull-up arrangements. Designers should verify that the configured timing window accommodates worst-case clock tolerance, interrupt latency, task scheduling, and startup behavior across the complete -40°C to +125°C operating range.
This product page consolidates verified manufacturer and distributor information, documented timing characteristics, package details, sourcing data, and design guidance. It also distinguishes the verified commercial TPS3431SDRBR alternative from unverified cross-brand options so engineers can make package- and qualification-aware decisions without relying on unsupported substitution claims.
Drop-in alternatives for TPS3431SQDRBRQ1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TPS3431SQDRBRQ1 (same form factor and footprint) — differing in Operating Temperature Range, Package.
TPS3431SDRBR
✅ Drop-InContact for price
View Datasheet →TPS3431SQDRBRQ1 Specifications
| Device Type | Programmable window watchdog timer |
| Automotive Qualification | Automotive standard |
| Watchdog Timeout Accuracy | 15% |
| Typical Timing Accuracy at 25°C | 2.5% |
| Operating Temperature Range | -40°C to +125°C |
| Supply Voltage Threshold | 1.21 V |
| Reset Output Type | Active-low, open-drain |
| Watchdog Enable | Enable pin and SET logic pins |
| Timeout Programming | External capacitor or factory-programmed default delay settings |
| Package | 8-pin VSON, 3.00 mm × 3.00 mm |
| Mounting Type | Surface mount |
| Package Wettable Flanks | Yes |
TPS3431SQDRBRQ1 yes Pin Configuration Guide
Pin configuration for TPS3431SQDRBRQ1 (yes package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for TPS3431SQDRBRQ1.
Refer to the datasheet for full pin configuration.
Typical Applications
TPS3431SQDRBRQ1 is suitable for 6 applications: Automotive Electronic Control Units, Industrial Motor-Control Modules, Battery-Powered Industrial Sensors, Safety Monitoring Subsystems, Embedded Communications Equipment, Development and Production Test Systems.
Automotive Electronic Control Units
The TPS3431SQDRBRQ1 fits automotive electronic control units that require a compact, qualified watchdog with defined upper and lower heartbeat boundaries. Its 15% timeout accuracy across -40°C to +125°C provides a defined timing tolerance for detecting late or early service from the controlling MCU, while 2.5% typical accuracy at 25°C supports tighter room-temperature timing. The 8-pin 3.00 mm × 3.00 mm VSON package conserves board area in dense powertrain, body, and chassis electronics. Its enable function can suppress nuisance watchdog events during controlled startup and development, and the active-low open-drain output provides a conventional reset-fault interface.
Industrial Motor-Control Modules
The TPS3431SQDRBRQ1 is appropriate for industrial motor controllers where a stuck or improperly scheduled control task must be detected quickly. Its window-watchdog behavior rejects both a missing heartbeat and an unexpectedly early transition, which is more diagnostic than a simple maximum-time supervisor. The -40°C to +125°C specification covers demanding industrial environments, while the 15% timeout tolerance must be included in the worst-case timing budget. Its compact VSON package reduces board footprint beside the motor driver and processor, and the enable input allows firmware-controlled deactivation during maintenance states.
Battery-Powered Industrial Sensors
A battery-powered industrial sensor can use the TPS3431SQDRBRQ1 to protect its embedded controller from software lockups and irregular task scheduling. The programmable window permits a timing profile that reflects the sensor’s intended heartbeat rather than a fixed maximum delay, and the external-capacitor option supports board-level configuration. The 3.00 mm × 3.00 mm 8-pin VSON package is useful where sensor housings limit PCB area. Designers should account for the specified 15% timing accuracy and 2.5% typical error at 25°C when choosing capacitor tolerance and setting the acceptable service interval.
Safety Monitoring Subsystems
The TPS3431SQDRBRQ1 can supervise a safety-monitoring microcontroller that periodically confirms correct health-check behavior. Because the device monitors a timing window, it can identify both a halted task and an incorrectly accelerated heartbeat, providing useful diagnostic coverage for redundant monitoring logic. Its 1.21 V threshold and active-low open-drain signaling align with common low-voltage supervisory architectures. The -40°C to +125°C range supports harsh operating environments, and the enable function permits controlled bypass during test or shutdown. Final suitability depends on the applicable functional-safety and vehicle-qualification requirements, which are not supplied in the verified data.
Embedded Communications Equipment
The TPS3431SQDRBRQ1 is suitable for communication equipment whose control processor must maintain a periodic service schedule to keep a link or protocol stack healthy. Its window timing can detect a delayed response and an early response, helping distinguish scheduler failures from ordinary variable processing load. The small 8-pin VSON package supports compact interface-control assemblies, while the open-drain fault output allows connection to a system reset or fault manager. Designers should verify that the timeout window includes worst-case network, interrupt, and flash-write latency and that the 15% tolerance is acceptable for the selected heartbeat interval.
Development and Production Test Systems
The TPS3431SQDRBRQ1 can simplify bring-up and production testing because its watchdog can be disabled through the enable pin or SET logic pins. This avoids forced resets while firmware is intentionally stopped, single-stepped, or held at breakpoints. The device still supports a factory-programmed default delay or external-capacitor timing when normal monitoring is required. Its 15% timeout accuracy and 2.5% typical accuracy at 25°C provide defined bounds for production timing checks, and the compact VSON package allows the monitor to be placed close to the controller under test. The exact disable logic and timing setup should be confirmed from the manufacturer datasheet.
Engineering reference data for TPS3431SQDRBRQ1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPS3431SDRBR |
|---|---|---|
| Package | 8-pin VSON, 3.00 mm × 3.00 mm | 8-pin VSON, 3.00 mm × 3.00 mm |
| Brand | Texas Instruments | Texas Instruments |
| Qualification Rating | Automotive standard | Commercial catalog |
| Supply Voltage Threshold | 1.21 V | 1.21 V |
Key Differentiators
- Automotive-standard qualification rating (vs TPS3431SDRBR)
- Defined timing accuracy across temperature (vs TPS3431SDRBR)
- Development-friendly disable controls (vs TPS3431SDRBR)
- Compact inspection-friendly package (vs TPS3431SDRBR)
Design Notes
Do not size the watchdog window from nominal timing alone. The verified TPS3431-Q1 specifications state 15% timeout accuracy over -40°C to +125°C and 2.5% typical accuracy at 25°C. Include watchdog tolerance, external-capacitor tolerance, clock error, interrupt latency, and firmware scheduling variation in the worst-case timing budget. A timing window that is too narrow can generate false resets, while an excessively wide window can delay fault detection.
Place the external timing capacitor and any associated routing close to the TPS3431SQDRBRQ1 to minimize parasitic capacitance and noise sensitivity. Keep the watchdog input and open-drain output away from fast switching nodes and noisy inductors. The open-drain output requires an appropriate pull-up arrangement, so confirm the system reset architecture and ensure the pull-up voltage remains within the device's verified operating limits before layout release.
The verified distributor specification lists a 1.21 V threshold for this part. Validate the power rail during startup, reset, and load transients so it remains above the device's operating requirements throughout the monitored interval. The enable pin or SET logic can disable the watchdog during development and controlled shutdown, but disabling it in production can mask a real system failure; apply a firmware and hardware strategy that prevents permanent bypass.
Do not treat TPS3431SDRBR as an unrestricted automotive substitute for TPS3431SQDRBRQ1. The verified comparison identifies automotive versus commercial catalog rating as the primary distinction. Use TPS3431SDRBR only for commercial designs or after a formal qualification review. Also avoid using generic competitor watchdog timers without verifying the 8-pin VSON footprint, pin mapping, 1.21 V threshold, timing behavior, open-drain output, and qualification requirements.
Compliance Information
The verified sources identify TPS3431SQDRBRQ1 as an automotive-standard TPS3431-Q1 device, but the supplied data does not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status.
