STMicroelectronics STM703M6F

Overview

STM703M6F from STMicroelectronics is a 5 V microprocessor supervisory IC with battery switchover, active-low and active-high reset outputs (RST/RST), 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 from –40 °C to +85 °C for industrial embedded systems requiring non-volatile SRAM backup control.

For engineers reviewing the STM703M6F datasheet, STM703M6F pinout, STM703M6F application, or STM703M6F equivalent, this device is selected for precise VCC monitoring, push-button reset coordination, automatic LPSRAM supply handover during main power loss, and early power-fail warning in battery-backed memory subsystems.

Technical Context

The STM703M6F implements dual-reset architecture with independent push-pull RST (active-low) and RST (active-high) outputs, both asserted synchronously during VCC undervoltage, MR activation, or power-fail detection. Its precision voltage reference monitors VCC against a fixed 4.65 V reset threshold (VRST) with hysteresis, ensuring clean reset release after recovery.

No watchdog timer is integrated - unlike STM690A/692A/802/805 - and chip-enable gating (E/ECON) is absent, distinguishing it from STM818. Battery switchover occurs at VSO = min(VBAT, VRST), enabling optimal battery life by delaying handover until VCC drops below 4.65 V or VBAT voltage, whichever is lower.

Key Specifications

Pinout & Package

STM703M6F is housed in an industry-standard SO8 (Small Outline 8-pin) package with 1.27 mm pitch, surface-mount footprint, and JEDEC MS-012AC compliance. Thermal resistance θJA = 150 °C/W enables reliable operation in compact industrial PCB layouts without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM703M6F, STM704M6F adds watchdog capability at identical cost and footprint but introduces unnecessary circuitry if unused, while MAX809TRD2T reduces feature set and package size but eliminates all battery-handling and dual-reset functionality required for LPSRAM systems.

Availability

STM703M6F is available at Aetrix Electronics and suitable for industrial PLCs, medical data loggers, point-of-sale terminals, and smart meters requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant sourcing.

Supply support for STM703M6F 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 sensing solutions for industrial, automotive, and consumer markets.

The STM69x/70x/80x supervisor family targets robust, low-power system-level monitoring in battery-backed memory applications, emphasizing precision voltage detection, seamless supply handover, and industrial temperature reliability.

FAQ

Does STM703M6F include a watchdog timer?

No. STM703M6F omits the watchdog timer present in STM690A, STM692A, STM704, and STM80x variants. Its logic diagram (Figure 2) and Table 1 confirm absence of WDI pin and watchdog function. This simplifies design where MCU self-monitoring is handled externally or not required.

What is the maximum allowable VBAT voltage relative to VCC?

VBAT may exceed VCC without damage or functional impact. Per Section 1.1.6 and Absolute Maximum Ratings (Table 5), VBAT is rated to 6.0 V, and the internal P-channel MOSFET switchover switch tolerates VBAT > VCC. Connect VBAT directly to a 3.0–3.6 V lithium coin cell or rechargeable backup source.

How does the power-fail comparator interact with the reset function?

PFI/PFO operates independently of the reset comparator. PFO asserts low when PFI < 2.4 V or VCC < VSO (≈4.65 V), providing early warning ~2.25 V before RST triggers. This allows firmware to execute emergency save routines prior to reset assertion, as confirmed in Figure 14 and Section 2.8.

Can VOUT be used to power devices other than LPSRAM?

VOUT is optimized for driving the CE# pin of low-power SRAMs (e.g., Cypress CY14B101QN) with minimal load current (<1 mA). Driving higher-current loads risks violating VOUT regulation specs and degrading trec timing accuracy; ST recommends using VOUT exclusively for SRAM chip-enable gating per datasheet application guidance.