STMicroelectronics STM706TM6F

Overview

STM706TM6F from STMicroelectronics is a precision 3 V supply voltage supervisor IC with active-low reset output, 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 +85 °C for industrial embedded control systems.

For engineers reviewing the STM706TM6F datasheet, STM706TM6F pinout, STM706TM6F application, or STM706TM6F equivalent, key selection criteria include reset threshold accuracy (3.00–3.15 V), push-pull RST output drive capability, MR debounced logic interface, WDO watchdog feedback path design, and PFO's early power-fail warning timing.

Technical Context

The STM706TM6F integrates a precision bandgap reference and comparator to monitor VCC against a fixed 3.00–3.15 V reset threshold (T-grade), asserting RST low on undervoltage, watchdog timeout, or MR activation. Its internal trec generator ensures minimum 200 ms reset pulse width after power-up or fault recovery.

It implements a self-clearing 1.6 s watchdog timer triggered by WDI edge transitions, with WDO providing open-drain-compatible push-pull output that can be fed back to MR for autonomous system recovery. The independent PFI/PFO pair uses a 1.25 V ±1% reference to detect pre-failure voltage droop on external supplies.

Key Specifications

Pinout & Package

STM706TM6F is housed in an 8-pin SOIC package (SO8, 150 mil body width) with standard JEDEC MS-012AC footprint and 1.27 mm pitch. Pin compatibility aligns with industry-standard microcontroller supervisory IC layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT46D3+ and TPS3808G33DBVR, STM706TM6F uniquely combines 3.00–3.15 V precision reset, integrated 1.6 s watchdog, and independent PFI/PFO in a standard SO8 footprint-enabling full-featured supervision without external components or configuration resistors.

Availability

STM706TM6F is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for STM706TM6F 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 analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The STM70x series is ST's dedicated family of single-chip voltage supervisors targeting cost-sensitive, space-constrained embedded systems needing reliable power-on reset, brown-out protection, and system-level fault recovery capabilities.

FAQ

What is the function of the WDO pin on STM706TM6F?

The WDO (Watchdog Output) pin is a push-pull active-low output that goes low after 1.6 s of inactivity on the WDI pin. It remains low until a WDI edge occurs or MR is asserted. When connected to MR, it creates an autonomous watchdog-triggered reset loop-critical for recovering from firmware hangs without host intervention.

Can STM706TM6F monitor a 5 V supply?

No-STM706TM6F is specified for 3 V operation with a 3.00–3.15 V reset threshold and absolute maximum VCC rating of 6 V. Applying 5 V continuously exceeds its design voltage range and risks parametric shift or damage. For 5 V systems, use STM708T/S/R variants or higher-threshold supervisors like STM706M.

How does the PFI/PFO function provide early power-fail warning?

PFI compares an external voltage (typically from a resistor divider on the unregulated input) to a stable 1.25 V internal reference. When PFI falls below 1.25 V, PFO asserts low-signaling impending supply collapse well before VCC reaches the 3.00 V reset threshold. This enables proactive data save or controlled shutdown.

Is external capacitor required on the MR pin?

An external 0.1 µF capacitor from MR to GND is recommended only in noisy environments or when MR is driven via long PCB traces. The pin includes a 40 kΩ internal pull-up, so no capacitor is needed for clean-board, short-trace implementations. Leaving MR open is electrically safe due to the internal pull-up.