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STMicroelectronics STWD100YNYWY3F
- Part No.:
- STWD100YNYWY3F
- Manufacturer:
- STMicroelectronics
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
STWD100YNYWY3F.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,773
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Product details
Overview
STWD100YNYWY3F from STMicroelectronics is an automotive-qualified, self-contained watchdog timer IC that monitors microcontroller operation via WDI input and asserts active-low WDO output on timeout. It offers four factory-set timeout periods (3.4 ms, 6.3 ms, 102 ms, 1.6 s), 13 µA typical supply current, and operates from –40 to 125 °C in SOT23-5 package. Used in automotive ECUs to prevent lockup-induced system failure.
For engineers reviewing the STWD100YNYWY3F datasheet, STWD100YNYWY3F pinout, STWD100YNYWY3F application, or STWD100YNYWY3F equivalent, key selection criteria include timeout period matching, EN pin enable logic, WDO output configuration (open-drain vs. push-pull), automotive qualification status, and thermal stability across extended temperature range.
Technical Context
The STWD100YNYWY3F implements a fixed-function watchdog with internal oscillator-based timing-no external components required. Its timeout period is permanently set to 1.6 s (per ordering code YNYWY3F), determined by internal resistor-capacitor network and verified per AEC-Q100 Grade 1.
Operation relies on periodic WDI toggling within tWD; failure triggers WDO assertion for tPW = 210 ms (typ.). The EN pin enables/disables monitoring with 1 µs minimum pulse width detection and internal 63 kΩ pull-down, allowing floating-enable default behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Watchdog timeout | 1.6 s (factory-configured; determines max MCU response window before system reset) |
| Supply current | 13 µA typ. at VCC = 5 V (enables low-power always-on monitoring in battery-backed systems) |
| Operating temp | –40 to 125 °C (meets automotive under-hood ambient requirements) |
| VCC range | 2.7 to 5.5 V (compatible with 3.3 V and 5 V logic domains without level-shifting) |
| WDO type | Active-low, open-drain or push-pull (supports flexible reset line interfacing; open-drain requires external pull-up) |
| EN input logic | Pull-down enabled; floating = enabled (simplifies board design-no external bias needed for default operation) |
| ESD rating | HBM: 2000 V, CDM: 1000 V (ensures robustness during handling and in-circuit transient events) |
Pinout & Package
STWD100YNYWY3F is packaged in SOT23-5 (5-pin small outline transistor) with 1.9 mm × 2.8 mm footprint, 0.95 mm pitch, and gull-wing leads suitable for automated assembly and high-reliability automotive applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (WDO) | Watchdog output | Active-low reset signal; open-drain or push-pull configurable-drives MCU reset line directly or via external pull-up |
| 2 (GND) | Ground reference | Primary return path for VCC and all I/O; must be low-impedance connection to minimize noise coupling into timing circuit |
| 3 (EN) | Chip enable | Logic-controlled watchdog activation; internal 63 kΩ pull-down ensures enabled-by-default when left floating |
| 4 (WDI) | Watchdog input | Edge-sensitive trigger; toggled by host MCU to reset internal timer-glitch rejection filters <100 ns noise |
| 5 (VCC) | Supply voltage | Power input (2.7–5.5 V); includes internal startup detection (VSTART = 2.2 V typ.) to delay timer activation until stable rail |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 qualified-validated for use in engine control, body electronics, and ADAS modules |
| Four selectable timeouts | Factory-programmed 1.6 s timeout eliminates need for external RC tuning or configuration pins |
| Low quiescent current | 13 µA typical ICC enables integration into always-on subsystems without compromising battery life |
| Robust enable architecture | EN pin accepts ≥1 µs pulses and rejects <100 ns glitches-prevents spurious disable/enable in noisy environments |
| Reset pulse width control | WDO asserts for 210 ms (typ.), ensuring reliable MCU reset assertion time across voltage and temperature |
Applications
| Engine Control Unit (ECU) | Advanced Driver Assistance Systems (ADAS) |
|---|---|
Use Scenario: Monitors real-time firmware execution in gasoline/diesel engine controllers where software hangs could cause unsafe torque delivery or emissions noncompliance. IC Role / Device Role / Timing Role: Standalone hardware safety monitor-asserts WDO to force ECU reset if WDI not toggled within 1.6 s. Use Value: Provides ASIL-B-aligned fail-safe behavior independent of MCU internal watchdog, meeting ISO 26262 functional safety requirements. | Use Scenario: Supervises vision processing or radar fusion algorithms in lane-keeping or automatic emergency braking modules. IC Role / Device Role / Timing Role: External watchdog timer verifying deterministic task scheduling; WDO connected to system-level reset controller. Use Value: Guarantees recovery from algorithmic deadlock or sensor data freeze-critical for maintaining operational readiness in safety-critical ADAS functions. |
| Body Control Module (BCM) | Automotive Infotainment Head Unit |
Use Scenario: Ensures reliability of door-lock, lighting, and climate control logic running on low-cost MCUs in harsh vehicle electrical environments. IC Role / Device Role / Timing Role: Hardware-level supervision of BCM firmware; EN pin tied to ignition signal for power-cycle synchronized enable. Use Value: Prevents BCM lockup causing loss of power windows or interior lighting-improves perceived vehicle quality and serviceability. | Use Scenario: Protects Linux-based infotainment systems against GUI freezes or audio stack crashes during Bluetooth streaming or navigation. IC Role / Device Role / Timing Role: Independent watchdog asserting WDO to cold-reset application processor while preserving baseband modem state. Use Value: Enables graceful recovery without full system reboot-maintains cellular connectivity and reduces user disruption during prolonged UI unresponsiveness. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar watchdog timer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6375KA+T | Fixed 1.6 s timeout, 1.8–5.5 V supply, 12 µA ICC, but no EN pin and only open-drain WDO | Lacks chip enable functionality-requires external logic for conditional watchdog activation | Select when EN functionality is unnecessary and lowest possible supply current is prioritized |
| TPS3823DBVR | Adjustable timeout (via external capacitor), 2.5–5.5 V, 20 µA ICC, push-pull WDO only, no WDI input | Timer is windowed (not standard watchdog); no WDI interface-relies on VCC monitoring only | Select for power-supply brownout protection rather than MCU execution monitoring |
Compared with MAX6375KA+T and TPS3823DBVR, STWD100YNYWY3F uniquely combines automotive qualification, dedicated WDI/WDO signaling, EN pin control, and factory-set 1.6 s timeout-making it optimal for MCU supervision in safety-critical automotive nodes where configurability is secondary to proven reliability.
Availability
STWD100YNYWY3F is available at Aetrix Electronics and suitable for automotive engine control units, ADAS domain controllers, and body electronics requiring stable component supply with AEC-Q100 compliance and long-term lifecycle support.
Supply support for STWD100YNYWY3F includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and analog products for automotive, industrial, and consumer markets.
The STWD100 product line delivers highly reliable, low-power watchdog timers specifically engineered for automotive-grade fault detection-targeting ECU, ADAS, and telematics applications demanding AEC-Q100 qualification and extended temperature operation.
FAQ
What is the exact watchdog timeout period for STWD100YNYWY3F?
The STWD100YNYWY3F has a factory-configured watchdog timeout period of 1.6 seconds (typical), with min/max values of 1.12 s and 2.24 s respectively, as specified in Table 4 of the official datasheet (DocID14134 Rev 11). This value is fixed and cannot be adjusted externally.
Does STWD100YNYWY3F support both open-drain and push-pull WDO outputs?
Yes-STWD100YNYWY3F supports both configurations. The output type is determined during manufacturing and indicated by the order code suffix; YNYWY3F uses open-drain WDO, requiring an external pull-up resistor (e.g., 10 kΩ) to the target reset rail, as confirmed in Section 3.2 of the datasheet.
How does the EN pin function, and what happens when it's left unconnected?
EN is an active-high enable input with an internal 63 kΩ pull-down resistor. When left floating, EN is pulled low by default, enabling the watchdog. To disable, apply ≥1 µs high pulse to EN; to re-enable, drive EN low again. Glitches shorter than 100 ns are ignored, per Section 3.3 and Table 4.
Is STWD100YNYWY3F compatible with 3.3 V microcontrollers?
Yes-STWD100YNYWY3F operates over 2.7–5.5 V, fully supporting 3.3 V systems. Its WDI input thresholds (VIH = 0.7×VCC, VIL = 0.3×VCC) and WDO output specs (VOL ≤ 0.4 V at ISINK = 3.2 mA) ensure clean interfacing with standard 3.3 V CMOS logic without level shifters.
STWD100YNYWY3F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Watchdog Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- -
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 1.12s Minimum
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
STWD100YNYWY3F FAQ
1.How can I place an order for STWD100YNYWY3F through Aetrix?
Please submit a Request for Quotation (RFQ) for STWD100YNYWY3F on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STWD100YNYWY3F reliable?
The price and inventory of STWD100YNYWY3F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STWD100YNYWY3F is usually 5 days.
3.What payment methods are accepted for STWD100YNYWY3F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STWD100YNYWY3F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STWD100YNYWY3F?
STWD100YNYWY3F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STWD100YNYWY3F order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STWD100YNYWY3F?
For technical support, including STWD100YNYWY3F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STWD100YNYWY3F requirements.
6.How does Aetrix verify that STWD100YNYWY3F is sourced from the original manufacturer or authorized distributors?
All STWD100YNYWY3F products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STWD100YNYWY3F meets industry standards.
7.What is the process for return or replacement of STWD100YNYWY3F?
All STWD100YNYWY3F units undergo pre-shipment inspection (PSI). If there is an issue with STWD100YNYWY3F, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STWD100YNYWY3F part is unused and in its original packaging.
Return procedure for STWD100YNYWY3F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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