STMicroelectronics STM706PM6E

Overview

STM706PM6E from STMicroelectronics is a precision 3 V supply voltage supervisor IC with active-high reset output, watchdog timer, manual reset input, and power-fail comparator. It asserts RST when VCC drops below 2.59–2.70 V, provides 200 ms reset timeout (trec), delivers 1.6 s watchdog timeout, and draws only 40 µA typical supply current. Used in industrial microcontroller systems requiring reliable power-on reset and brownout detection.

For engineers reviewing the STM706PM6E datasheet, STM706PM6E pinout, STM706PM6E application, or STM706PM6E equivalent, key selection criteria include reset threshold tolerance (±2.2% over temperature), guaranteed RST assertion down to VCC = 1.0 V, push-pull RST/RST/WDO/PFO outputs, and compatibility with bi-directional MCU reset pins via series resistor interface.

Technical Context

The STM706PM6E integrates a precision bandgap reference, dual comparators (VCC monitor and PFI threshold), a 1.6 s watchdog timer with WDI edge-sensitive clearing, and independent trec timing circuitry. Its RST output remains high for VCC ≥ VRST and asserts low only during fault conditions - unlike STM706R, it uses active-high reset logic while retaining identical pinout and functional scope.

It features push-pull outputs on RST, WDO, PFO, and MR (with internal 40 kΩ pull-up), enabling direct interfacing without external pull resistors. The PFI comparator operates independently of the VCC monitor, with VPFI = 1.25 V ±1.2%, allowing early power-fail warning before VCC collapse.

Key Specifications

Pinout & Package

STM706PM6E is housed in an 8-pin SOIC package (SO8, 150 mil body width) with standard JEDEC MS-012AC footprint and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM706RM6E, STM706PM6E eliminates level-shifting needs for active-high reset MCUs; versus MAX6326US26D3+, it consolidates watchdog, PFI, and dual-reset outputs into one SO8 device-reducing BOM count and PCB area by 30% in supervisory-critical systems.

Availability

STM706PM6E is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, smart energy meters, and automated test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STM706PM6E 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/mixed-signal devices for industrial, automotive, and consumer markets.

The STM70x supervisor family targets robust power monitoring in resource-constrained embedded systems, emphasizing precision threshold stability, low power, and integrated fault-detection functions without external components.

FAQ

Can STM706PM6E be used with a 5 V supply?

Yes. STM706PM6E supports VCC from 1.0 V to 5.5 V. Its internal voltage reference and comparators remain accurate across this range, and RST assertion is guaranteed down to VCC = 1.0 V. At 5 V, supply current rises to ~65 µA (typ.), well within specification, and all outputs maintain push-pull drive strength per datasheet DC characteristics.

How is the watchdog timer disabled?

The watchdog timer is disabled by leaving WDI floating or tri-stating its driver. When WDI is open-circuited, leakage current must stay below 10 µA and load capacitance under 200 pF. No external pull-up/down is required-the internal circuitry halts timing automatically, confirmed in Section 2.2 and Figure 28 of the datasheet.

What is the purpose of the PFI/PFO function?

PFI monitors an external voltage (e.g., unregulated input or divided VCC) against a fixed 1.25 V reference. When PFI falls below that threshold, PFO asserts low-providing early warning of impending power failure before VCC drops below the 2.65 V reset threshold. This allows time-critical systems to save state or initiate controlled shutdown.

Does STM706PM6E require external capacitors?

No external timing capacitors are needed. All timing functions-including trec (200 ms), watchdog timeout (1.6 s), and propagation delays-are internally generated. A 0.1 µF bypass capacitor on VCC is recommended per layout guidelines, and optional 0.1 µF noise-filtering cap on MR is advised only in high-noise environments-not required for basic operation.