Monolithic Power Systems Inc. EV6411-S-00A

Overview

EV6411-S-00A from Monolithic Power Systems is an evaluation board for the MPQ6411GS windowed watchdog timer IC, designed to monitor and reset microcontrollers in safety-critical embedded systems. It supports programmable short/long window modes, power-on and undervoltage reset (active-low), and watchdog disable via /WD_DIS pin. The board operates at 5.0 V and uses a SOIC8-mounted MPQ6411GS for functional validation.

For engineers reviewing the EV6411-S-00A datasheet, EV6411-S-00A pinout, EV6411-S-00A application, or EV6411-S-00A equivalent, this board enables rapid verification of windowed watchdog timing behavior, mode selection logic (MODE pin), reset assertion conditions (WDO), trigger input response (WDI), and disable functionality (/WD_DIS) under real-world MCU interface scenarios.

Technical Context

The EV6411-S-00A implements the MPQ6411GS's full windowed watchdog functionality: it accepts a cyclic trigger signal on WDI within a user-defined time window, asserts an active-low reset on WDO if missed, and provides power-on/undervoltage reset. The MODE pin selects between long and short window timing profiles, while /WD_DIS allows hardware-level watchdog disable.

Timing is set by external resistor R5 (51 kΩ populated), yielding a nominal timeout period calculated as T = 15.75 μs + (73 × R5) μs - confirming precise, resistor-programmable window duration. All critical signals (WDI, WDO, /WD_DIS, MODE, TIME) are accessible via test points or headers for oscilloscope probing and MCU integration testing.

Key Specifications

Availability

EV6411-S-00A is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, and medical device controllers requiring stable component supply, functional safety validation, and early-stage watchdog timer integration.

Supply support for EV6411-S-00A 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 the US.

The MPQ6411 product line delivers windowed watchdog timers for functional safety applications where deterministic reset behavior and configurable timing windows are required - targeting automotive ASIL-B and industrial IEC 61508 environments.

FAQ

What is the purpose of the /WD_DIS pin on the EV6411-S-00A?

The /WD_DIS pin disables the watchdog function when pulled below 0.8 V. At 5 V supply, driving it above 3.2 V enables operation; floating it defaults to enabled state. This allows safe MCU boot sequences or debug-mode suspension without removing hardware connections.

How is the watchdog timeout period set on this evaluation board?

Timeout is set by resistor R5 (populated with 51 kΩ). The formula T = 15.75 μs + (73 × R5) μs yields ~3.75 ms nominal. Changing R5 adjusts window duration linearly, enabling precise tuning for specific MCU firmware execution cycles.

Can the EV6411-S-00A be used with 3.3 V microcontrollers?

No - the board is configured for 5.0 V operation only, and the MPQ6411GS is specified for 4.5–5.5 V supply. Its logic thresholds (0.8 V / 3.2 V) are referenced to VCC, so direct 3.3 V MCU interfacing requires level-shifting for WDI, MODE, and /WD_DIS signals.

What does "windowed" watchdog mean in this context?

It means the MPQ6411GS requires the WDI trigger signal to arrive within a defined time window - neither too early nor too late. This prevents false resets from jitter or runaway code that pulses too fast, enhancing reliability over basic timeout-only watchdogs.

Is the EV6411-S-00A RoHS-compliant and lead-free?

Yes - all components on the board, including the MPQ6411GS IC and passive parts, are lead-free, halogen-free, and compliant with the EU RoHS directive, as confirmed in the official MPS documentation and BOM.

Does the board include power-on reset functionality?

Yes - the MPQ6411GS generates an active-low reset pulse on WDO during power-up and whenever VCC drops below the undervoltage lockout threshold (~4.25 V), ensuring clean MCU initialization before stable supply is achieved.