STMicroelectronics STM706SDS6F

Overview

STM706SDS6F from STMicroelectronics is a precision 3 V supply voltage supervisor IC with active-low reset (RST), watchdog timer, manual reset input (MR), and power-fail comparator (PFI/PFO). It asserts reset for VCC < 2.88 V (S-grade), features 200 ms reset timeout (trec), 1.6 s watchdog timeout, 40 µA typical supply current, and operates from –40 °C to +85 °C. It is used in industrial controllers and embedded systems requiring reliable power-on and brownout reset.

For engineers reviewing the STM706SDS6F datasheet, STM706SDS6F pinout, STM706SDS6F application, or STM706SDS6F equivalent, key selection criteria include reset threshold tolerance (±2.5% over temperature), guaranteed RST assertion down to VCC = 1.0 V, push-pull RST/RST outputs, WDO-MR watchdog feedback capability, and TSSOP8 package compatibility with space-constrained PCB layouts.

Technical Context

The STM706SDS6F implements dual independent comparators: one for VCC monitoring (VRST = 2.88–3.00 V) and another for power-fail detection (VPFI ≈ 1.25 V), each driving dedicated push-pull outputs. Its internal 1.6 s watchdog timer clears on WDI edge transitions and triggers WDO only-not RST-unless externally wired to MR.

Reset assertion is guaranteed across full industrial temperature range and remains valid down to VCC = 1.0 V due to internal charge-pump-assisted output stage; trec is fixed at 200 ms (typ.) and temperature-stable (±1.5% variation from –40 °C to +85 °C).

Key Specifications

Pinout & Package

The STM706SDS6F is housed in an 8-pin TSSOP package (3 mm × 3 mm body, DS suffix), optimized for high-density PCB layouts and automated assembly. Pin pitch is 0.65 mm; thermal pad optional per manufacturer recommendation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361LCS16+T and TPS3808G33DBVR, the STM706SDS6F uniquely integrates watchdog timing, dual-supply monitoring (VCC + PFI), and guaranteed sub-1.0 V reset assertion - making it the only option among the three capable of coordinated brownout response and firmware crash recovery in a single TSSOP8 package.

Availability

STM706SDS6F is available at Aetrix Electronics and suitable for industrial controllers, medical diagnostic instruments, smart energy meters, and ruggedized HMI terminals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM706SDS6F 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 industrial, automotive, and consumer markets.

The STM706 series belongs to ST's precision voltage supervisor product line, engineered specifically for robust power-monitoring in resource-constrained embedded systems where deterministic reset behavior and fault resilience are mandatory.

FAQ

What is the exact reset threshold range for STM706SDS6F?

The STM706SDS6F is the 'S' grade variant, with a guaranteed reset threshold (VRST) of 2.88 V to 3.00 V at 25 °C. This range is maintained with ±1% maximum drift over the full –40 °C to +85 °C operating temperature range, as validated in Table 6 of the official datasheet (DocID10518 Rev 14).

Can the watchdog timer be disabled without modifying the PCB?

Yes - the watchdog function is automatically disabled when the WDI pin is left floating or tri-stated. The internal timer requires edge transitions (rising or falling) to reset; absence of toggling for >1.6 s has no effect unless WDI is actively driven. No solder jumper or external component is needed.

Is the PFO output compatible with a 5 V microcontroller reset input?

No - PFO is a 3 V push-pull output referenced to VCC (3 V). Driving a 5 V-tolerant MCU reset pin is acceptable only if the MCU specifies 3 V-compatible input thresholds (e.g., VIH ≥ 2.0 V). For strict 5 V logic systems, a level-shifting buffer or open-drain translator is required.

Does STM706SDS6F support reset assertion during power-down sequences?

Yes - the device guarantees RST remains low down to VCC = 1.0 V across the full industrial temperature range. Below 1.0 V, RST becomes high-impedance; adding a 100 kΩ pulldown resistor (as shown in Figure 10 of the datasheet) ensures it stays low through full power collapse.