STMicroelectronics STM706M6F

Overview

STM706M6F from STMicroelectronics is a 5 V precision voltage supervisor IC with dual reset outputs (active-low RST and active-high RST), integrated watchdog timer (1.6 s timeout), manual reset input (MR), and power-fail comparator (PFI/PFO). It guarantees RST assertion down to VCC = 1.0 V, features 200 ms typical reset timeout (trec), and operates across –40 °C to 125 °C for automotive-grade reliability in engine control units and ADAS modules.

For engineers reviewing the STM706M6F datasheet, STM706M6F pinout, STM706M6F application, or STM706M6F equivalent, key selection criteria include its 4.25–4.50 V reset threshold, push-pull RST/RST outputs, MR-driven reset hold timing, WDI watchdog edge-sensitivity, and PFI threshold of 1.25 V ±10 mV - all critical for fail-safe microcontroller supervision in safety-critical embedded systems.

Technical Context

The STM706M6F implements a dual-comparator architecture: one precision bandgap reference monitors VCC against a 4.25–4.50 V reset threshold (VRST), while a separate 1.25 V reference compares PFI for early power-fail detection. Its watchdog timer resets on missing WDI transitions within 1.6 s (±5%), and clears on any rising/falling edge - supporting both pulse and level-based MCU supervision.

RST and RST outputs are independently driven push-pull buffers, enabling direct interface with bidirectional MCU reset pins via series resistors. The MR input includes an internal 40 kΩ pull-up, allowing switch-to-ground operation without external components, and holds reset asserted for trec (200 ms typ) after MR release - ensuring reliable de-bounced reset recovery.

Key Specifications

Pinout & Package

STM706M6F is housed in an 8-pin TSSOP package (3 mm × 3 mm body, 0.65 mm pitch), optimized for space-constrained automotive and industrial PCBs. Pin functions are validated per STMicroelectronics DocID10520 Rev 11, Figures 4 and 7.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX692AESA+ and TPS3808G33DBVR, the STM706M6F uniquely combines automotive-grade temperature range, dual reset polarity, integrated watchdog, and predictive power-fail detection - making it irreplaceable in safety-critical 5 V ECU and ADAS designs where coordinated subsystem reset and early failure warning are mandatory.

Availability

STM706M6F is available at Aetrix Electronics and suitable for automotive engine control, ADAS domain controllers, and industrial PLC I/O modules requiring stable component supply with long-term lifecycle assurance and AEC-Q100-compliant traceability.

Supply support for STM706M6F 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 devices for automotive, industrial, and consumer markets.

The STM70x family was engineered specifically for robust microprocessor supervision in harsh environments, emphasizing precision reset thresholds, guaranteed low-VCC operation, and integrated fault-detection features for automotive and industrial control systems.

FAQ

Can STM706M6F be used in 3.3 V systems?

No. STM706M6F is specified for 4.5–5.5 V operation only. Its 4.25–4.50 V reset threshold and internal bandgap reference are calibrated for 5 V rails. Using it below 4.5 V risks unreliable reset assertion and violates absolute maximum ratings - select TPS3808G33 or MAX6326 for 3.3 V applications.

How is the watchdog timer disabled?

The watchdog is disabled by leaving WDI floating or tri-stating its driver. Internal leakage limits require WDI net capacitance ≤200 pF and leakage current ≤10 µA. Do not tie WDI to VCC or GND - that forces continuous timeout and repeated reset assertion via WDO→MR connection.

What is the purpose of the dual RST/RST outputs?

RST (active-low) and RST (active-high) provide simultaneous complementary reset signals to interface with MCUs having either reset polarity requirement - eliminating external inverters. This simplifies PCB layout and ensures deterministic timing alignment between reset assertion and release across heterogeneous subsystems.

Does STM706M6F support reset extension beyond 200 ms?

No. The 200 ms reset timeout (trec) is fixed and unadjustable. It is generated by an internal RC oscillator and trimmed during test. For longer delays, external circuitry (e.g., monostable multivibrator triggered by RST) is required - but this adds complexity and reduces reliability versus the integrated solution.