STMicroelectronics STM706M6E

Overview

STM706M6E from STMicroelectronics is an industrial-grade 5 V microprocessor supervisory IC with precision reset threshold (4.25–4.50 V), 200 ms reset timeout, 1.6 s watchdog timer, active-low and active-high RST outputs, and power-fail comparator (PFI/PFO). It monitors VCC for undervoltage conditions and asserts reset during power-up, brownout, or software hang-used in embedded controllers requiring reliable cold-start and fault recovery.

For engineers reviewing the STM706M6E datasheet, STM706M6E pinout, STM706M6E application, or STM706M6E equivalent, key selection criteria include its dual RST polarity support, guaranteed reset assertion down to VCC = 1.0 V, automotive-grade temperature option (–40 °C to 125 °C), and push-pull PFO/WDO outputs enabling direct MR tie-back without external pull-ups.

Technical Context

The STM706M6E integrates a precision voltage reference comparator for VCC monitoring, a 1.6 s watchdog timer with edge-sensitive WDI input, and independent power-fail detection using VPFI = 1.25 V nominal. Its dual RST outputs (RST and RST) allow simultaneous interface to both active-low and active-high reset domains.

Reset assertion is guaranteed down to VCC = 1.0 V across –40 °C to 85 °C (industrial grade); the automotive-grade variant extends operation to 125 °C. The internal 40 µA supply current and push-pull output drivers eliminate need for external biasing on RST, WDO, and PFO pins.

Key Specifications

Pinout & Package

STM706M6E is housed in an 8-pin TSSOP package (3 mm × 3 mm body, 0.65 mm pitch), RoHS-compliant and optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G18DBVR, the STM706M6E delivers integrated watchdog, dual-RST polarity, and power-fail detection in a single 8-pin TSSOP-reducing component count and validation scope for full-featured 5 V supervision.

Availability

STM706M6E is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, medical devices, and point-of-sale terminals requiring stable component supply and long-term lifecycle support.

Supply support for STM706M6E 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 silicon solutions for automotive, industrial, and consumer markets.

The STM70x series targets robust, low-cost microprocessor supervision in space- and power-constrained embedded systems, emphasizing guaranteed reset behavior, integrated fault detection, and industrial/automotive qualification.

FAQ

What is the function of the WDO pin on STM706M6E?

WDO is a push-pull active-low watchdog output that goes low when the WDI pin remains static for ≥1.6 s (watchdog timeout) or when VCC falls below VRST. It returns high immediately upon VCC recovery or WDI edge detection. WDO is commonly tied to MR to generate a hardware reset on timeout, enabling autonomous MCU recovery without software intervention.

Can STM706M6E monitor a 3.3 V supply directly?

No-STM706M6E is specified for 5 V operation (VCC = 4.5–5.5 V) and has a fixed 4.25–4.50 V reset threshold. To supervise a 3.3 V rail, connect it to the PFI pin via a resistor divider scaled to deliver ≤1.25 V at PFI when the 3.3 V rail drops to the desired warning threshold (e.g., 3.0 V), triggering PFO assert.

How does the STM706M6E ensure reset validity during deep brownout?

STM706M6E guarantees RST remains valid (logic low) down to VCC = 1.0 V at temperatures from –40 °C to +85 °C. This is achieved via internal low-voltage biasing and comparator design, ensuring the MCU receives a clean, unambiguous reset signal even during capacitor discharge or severe supply sag-critical for data integrity in nonvolatile memory operations.

Is the MR pin internally pulled up, and what is its pull-up strength?

Yes-the MR pin features an internal 40 kΩ pull-up resistor to VCC, allowing it to be left unconnected when unused. This value ensures reliable logic-high bias while permitting direct connection to ground via a momentary switch or open-drain driver without external components. No external pull-up is required for basic manual reset functionality.