Monolithic Power Systems Inc. MPQ6411GS-33-AEC1

Overview

MPQ6411GS-33-AEC1 from Monolithic Power Systems is a windowed watchdog timer IC designed for automotive microcontroller supervision, operating at 3.3V supply, supporting programmable short/long window modes (t2/t3 = 15/10 cycles or t4/t5 = 1500/1000 cycles), delivering low-voltage power-on reset (VPOR-LOW = 2.8–2.9V), and qualified to AEC-Q100 Grade 1 (−40°C to +125°C).

For engineers reviewing the MPQ6411GS-33-AEC1 datasheet, MPQ6411GS-33-AEC1 pinout, MPQ6411GS-33-AEC1 application, or MPQ6411GS-33-AEC1 equivalent, this device serves as a safety-critical timing monitor in engine control units, ADAS domain controllers, and battery management systems where deterministic reset behavior and voltage fault detection are mandatory.

Technical Context

The MPQ6411GS-33-AEC1 implements a state-machine-based windowed watchdog with dual-mode operation controlled by the MODE pin: short-window mode (15-cycle close / 10-cycle open) and long-window mode (1500-cycle close / 1000-cycle open), both synchronized to WDI_OK pulses derived from MCU-triggered WDI transitions.

It integrates power-on reset generation with hysteresis (VPOR-HIGH = 2.9–3.1V, VPOR-LOW = 2.8–2.9V), watchdog disable via /WD_DIS (active-low, weak internal pull-up), and open-drain WDO output requiring external pull-up (100kΩ typical), all operating across −40°C to +125°C junction temperature.

Key Specifications

Pinout & Package

MPQ6411GS-33-AEC1 is housed in an SOIC-8 package (JEDEC MS-012 AA, 150 mil width), with gull-wing leads, 1.27 mm pitch, and RoHS-compliant lead-free/halogen-free construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar windowed watchdog timer applications.

Compared with PCF2129AT and TLE7272-2SA, MPQ6411GS-33-AEC1 uniquely delivers AEC-Q100 Grade 1-certified windowed supervision with programmable dual-mode timing, integrated POR hysteresis, and sub-20 µA quiescent current-making it optimal for single-MCU ASIL-B systems where timing determinism and low power are critical.

Availability

MPQ6411GS-33-AEC1 is available at Aetrix Electronics and suitable for automotive engine control units, ADAS camera modules, and electric vehicle battery management systems requiring stable component supply with full AEC-Q100 traceability and long-term lifecycle assurance.

Supply support for MPQ6411GS-33-AEC1 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers across Asia and North America and global manufacturing partnerships.

The MPQ6411 product line targets functional-safety-critical automotive subsystems, delivering AEC-Q100-qualified timing supervision ICs that simplify ASIL-B compliance through deterministic windowed watchdog behavior and robust voltage monitoring.

FAQ

What is the exact power-on reset behavior of MPQ6411GS-33-AEC1?

Upon power-up, WDO remains low until VCC reaches VPOR-HIGH (2.9–3.1V), then stays low for t0 = 10 cycles (~8.8 ms with RTIMER = 51kΩ) to ensure MCU reset completion. During brown-out, WDO pulls low again when VCC falls below VPOR-LOW (2.8–2.9V), providing hysteresis of ~0.1V to prevent chatter.

How does the MODE pin affect watchdog timing resolution?

When MODE = low, the watchdog uses short-window timing (t2 = 15 cycles, t3 = 10 cycles); when MODE = high, it switches to long-window timing (t4 = 1500 cycles, t5 = 1000 cycles). All values scale linearly with RTIMER-e.g., doubling RTIMER doubles all cycle-based durations.

Can MPQ6411GS-33-AEC1 be used with a 5V MCU system?

No-MPQ6411GS-33-AEC1 is specified only for 3.3V operation (VCC = 3.3V ±10%). Its input thresholds (WDI logic high = 2.1V, MODE logic high = 2.1V) and WDO open-drain structure require external pull-up to 3.3V; using 5V violates absolute maximum ratings and invalidates AEC-Q100 qualification.

What happens if the WDI signal is held low longer than 5 ms?

The device detects a WDI error and forces WDO low continuously until WDI returns high. This failsafe behavior prevents MCU lockup from being masked by periodic WDI toggling and ensures immediate reset upon sustained signal fault-critical for ASIL-B diagnostics.

Is the /WD_DIS pin required to be actively driven in production systems?

No-/WD_DIS has a weak internal pull-up, so leaving it unconnected enables the watchdog by default. It should only be driven low during specific phases (e.g., bootloader execution or factory test) where temporary watchdog disable is necessary and safety-controlled.

How is the TIMER pin's external resistor value calculated?

RTIMER (kΩ) = 0.063 × T(µs) − 4.67, where T is the desired base period. For example, to achieve T = 880 µs (as in datasheet), RTIMER = 0.063 × 880 − 4.67 ≈ 51 kΩ. The relationship is linear and validated across −40°C to +125°C.

Does MPQ6411GS-33-AEC1 support watchdog window adjustment without changing hardware?

No-window timing is set solely by RTIMER value and MODE pin state; there is no register-based or I²C/SPI programmability. Hardware configuration (resistor selection and MODE routing) defines timing, ensuring deterministic behavior required for ISO 26262 compliance.