Monolithic Power Systems Inc. MPQ6411GS-AEC1-P

Overview

MPQ6411GS-AEC1-P from Monolithic Power Systems is a windowed watchdog timer IC qualified to AEC-Q100 Grade 1 for automotive use. It monitors microcontroller health by validating cyclic trigger signals (WDI) within programmable time windows, asserts a low-active reset (WDO) on timeout or power-up/undervoltage, and supports dual window modes (short: 15–10 cycles; long: 1500–1000 cycles) via MODE pin. Used in engine control units and ADAS domain controllers.

For engineers reviewing the MPQ6411GS-AEC1-P datasheet, MPQ6411GS-AEC1-P pinout, MPQ6411GS-AEC1-P application, or MPQ6411GS-AEC1-P equivalent, this page delivers verified electrical specs, SOIC-8 terminal mapping, AEC-Q100 timing behavior, and automotive-grade reset coordination logic - critical for functional safety validation and ISO 26262-compliant system design.

Technical Context

The MPQ6411 implements a state-machine-based windowed watchdog with three core operational phases: sync signal monitoring (t₁ = 450 cycles), window open/close evaluation (t₂/t₃ or t₄/t₅), and reset pulse generation (t₆ = 4 cycles). Its internal POR circuit triggers WDO low at VCC ≥ 1V and holds reset for t₀ = 10 cycles after VCC reaches 90% of nominal.

Window mode selection is hardware-driven: MODE = low enables short-window operation (t₂ = 15 cycles, t₃ = 10 cycles); MODE = high enables long-window operation (t₄ = 1500 cycles, t₅ = 1000 cycles). The /WD_DIS pin provides hardware-level watchdog disable capability with weak internal pull-up, ensuring default enablement when left floating.

Key Specifications

Pinout & Package

MPQ6411GS-AEC1-P is housed in an industry-standard SOIC-8 package (5.0mm × 4.0mm, 1.27mm pitch) with exposed pad not present. Pin functions are electrically validated per Monolithic Power Systems Rev. 1.1 datasheet and support automotive PCB layout requirements including thermal derating (θJA = 96°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCF2129AT and ISL80101IRAJZ, MPQ6411GS-AEC1-P uniquely combines hardware-programmable window modes, zero-firmware dependency, and AEC-Q100 Grade 1 qualification - making it optimal for ASIL-B–aligned systems needing deterministic, pin-controlled watchdog behavior from power-on through runtime.

Availability

MPQ6411GS-AEC1-P is available at Aetrix Electronics and suitable for engine control units, ADAS domain controllers, and electric power steering systems requiring stable component supply across automotive production lifecycles.

Supply support for MPQ6411GS-AEC1-P 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 in the US, China, and Taiwan.

The MPQ6411 belongs to MPS's automotive-grade watchdog timer product line, engineered specifically for functional safety-critical applications requiring AEC-Q100 qualification, deterministic timing, and minimal external components.

FAQ

What is the exact reset pulse width (t₆) of MPQ6411GS-AEC1-P?

The WDO reset pulse width t₆ is 4 cycles of the internal timer base period. With RTIMER = 51kΩ (T ≈ 880µs), t₆ = 4 × 880µs = 3.52ms. This value is derived from bench characterization and remains consistent across −40°C to +125°C operating junction temperature.

Does MPQ6411GS-AEC1-P require an external pull-up on WDO?

Yes - WDO is an open-drain output in the MPQ6411-33 variant, but MPQ6411GS-AEC1-P uses the 5V version with an inverter output structure. While it can drive low actively, a pull-up resistor (e.g., 10kΩ to VCC) is recommended to ensure clean high-level signaling and noise immunity in automotive harness environments.

How does the /WD_DIS pin behave when left unconnected?

The /WD_DIS pin has a weak internal pull-up, so leaving it unconnected defaults the watchdog to enabled state. This ensures fail-safe operation: if the disable signal line is severed or floats, the watchdog remains active and continues monitoring the MCU - a key requirement for ASIL-B systems.

Can MODE pin be driven by a microcontroller GPIO during operation?

Yes - MODE is sampled continuously during normal operation. Switching MODE from low to high transitions the watchdog from short to long window mode immediately upon next WDI_OK edge, and vice versa. This enables dynamic adaptation to changing MCU task loads without reset or reconfiguration overhead.

What is the maximum allowable TIMER pin voltage?

The TIMER pin is internally biased and must not exceed VCC. Absolute maximum rating for all pins is −0.3V to +6V, but operation above VCC risks incorrect timing and potential latch-up. Designers must ensure TIMER node stays within 0V to VCC (5V) range using standard 51kΩ resistor connection without additional voltage sources.

Is MPQ6411GS-AEC1-P compatible with 3.3V microcontrollers?

No - MPQ6411GS-AEC1-P is the 5V-supply variant (VCC = 5V ±10%). For 3.3V systems, use MPQ6411GS-33-AEC1. Input thresholds differ: WDI logic high is 3.2V min for MPQ6411GS-AEC1-P, incompatible with 3.3V MCU outputs unless level-shifted.

How is the POR threshold affected by temperature?

VPOR-HIGH and VPOR-LOW exhibit ±0.1V variation over −40°C to +125°C. At TJ = 125°C, VPOR-HIGH drops to 4.5V min and VPOR-LOW to 4.4V min - ensuring robust reset assertion during hot cranking while avoiding premature release in high-temp under-hood environments.