Monolithic Power Systems Inc. MP6411GS-P

Overview

MP6411GS-P from Monolithic Power Systems is a windowed watchdog timer IC designed to monitor microcontroller health and assert a low-active reset signal (WDO) during power-up, brown-out, or missed trigger events. It supports 5V supply, offers programmable short/long window modes via MODE pin, features /WD_DIS disable control, and operates in SOIC-8 package with external resistor-set timing (RTIMER = 51kΩ yields ~880µs period).

For engineers reviewing the MP6411GS-P datasheet, MP6411GS-P pinout, MP6411GS-P application, or MP6411GS-P equivalent, key selection criteria include POR threshold (4.4–4.8V), watchdog window timing resolution (15–1500 cycles), WDO open-drain vs. inverter output behavior, and compatibility with MCU-level sync pulse width (10–5000µs).

Technical Context

The MP6411GS-P implements a state-machine-based windowed watchdog with two distinct timing windows-short mode (t2=15 cycles, t3=10 cycles) and long mode (t4=1500 cycles, t5=1000 cycles)-both derived from an internal oscillator synchronized to WDI pulses. Its POR circuit asserts WDO low until VCC rises above 4.4V (typ.) and sustains reset for t0 = 10 cycles (~8.8ms at RTIMER=51kΩ).

It integrates three configurable control inputs: MODE selects window length, /WD_DIS enables/disables watchdog operation (weak internal pull-up), and WDI accepts MCU-trigger pulses with validated high/low thresholds (3.2V/0.8V at 5V VCC). WDO output is an inverter-type driver-not open-drain-eliminating need for external pull-up.

Key Specifications

Pinout & Package

MP6411GS-P is housed in an industry-standard SOIC-8 package (5.0mm × 6.2mm, 1.27mm pitch), with exposed pad omitted and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6373KA+T and TPS3823DBVR, the MP6411GS-P uniquely delivers field-reconfigurable window timing, inverter-output WDO eliminating BOM components, and tighter POR threshold control-making it optimal for adaptive, space-constrained, and safety-certifiable designs.

Availability

MP6411GS-P is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O subsystems, medical infusion pump controllers, and railway signaling interface units requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.

Supply support for MP6411GS-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 across Asia and North America.

The MP6411 belongs to MPS's precision timing and supervisory IC product line, engineered specifically for functional-safety-critical embedded systems demanding configurable, low-power, and rail-specific watchdog supervision.

FAQ

What is the exact power supply requirement for MP6411GS-P?

The MP6411GS-P requires a nominal 5V ±10% supply (4.5V to 5.5V). It is not rated for 3.3V operation-use MP6411GS-33 for that voltage. The POR circuit activates WDO below 4.4V and releases it only after VCC exceeds 4.8V (max), ensuring robust power-rail qualification before MCU release.

How does the /WD_DIS pin behave when left unconnected?

When /WD_DIS is left floating, its internal weak pull-up resistor asserts a logic high, enabling normal watchdog operation. To disable the watchdog-e.g., during firmware debugging-drive /WD_DIS low externally. No external pull-up is required, and tying it directly to GND fully disables reset generation regardless of WDI activity.

Is an external pull-up resistor required on the WDO pin?

No. Unlike open-drain watchdog outputs, MP6411GS-P's WDO is an inverter-type driver capable of actively pulling low and passively releasing high through internal circuitry. Connecting WDO directly to an MCU's active-low RESET pin is sufficient; adding an external pull-up risks contention and violates the recommended interface.

What determines the watchdog window timing values t2–t5?

Window timing values are integer multiples of the base period T, which is set by the external RTIMER resistor. At RTIMER = 51kΩ, T ≈ 880µs; thus short-mode t2 = 15 × T ≈ 13.2ms and t3 = 10 × T ≈ 8.8ms. All cycle counts (t1–t6) scale linearly with RTIMER value-no recalibration needed when adjusting T.

Can MP6411GS-P be used in AEC-Q100 qualified automotive designs?

While MP6411GS-P itself is not AEC-Q100 certified, it is widely deployed in AEC-Q200-compliant passive subcircuits and meets automotive-grade temperature range (–40°C to +125°C junction), Pb-free/halogen-free construction, and SOIC-8 thermal performance (θJA = 96°C/W). System-level qualification requires validation per ISO 26262 ASIL-B/C requirements.

What happens if the WDI signal stays low longer than 5000µs?

If WDI remains low beyond the maximum allowed pulse width (5000µs), the MP6411GS-P interprets this as a WDI error condition and forces WDO low continuously until WDI returns high. This failsafe behavior prevents indefinite MCU operation under invalid or stuck synchronization signals.

How does the MODE pin affect window timing in real time?

The MODE pin is sampled synchronously on each valid WDI_OK edge. Switching MODE high-to-low or low-to-high mid-operation causes immediate transition to the corresponding window mode on the next watchdog cycle-enabling dynamic adaptation to changing MCU task loads without reset or reinitialization.