STMicroelectronics STM708SDS6E

Overview

STM708SDS6E from STMicroelectronics is a 3 V precision voltage supervisor IC with active-low and active-high reset outputs, 200 ms reset timeout (trec), 1.6 s watchdog timer, and power-fail comparator (PFI/PFO). It monitors VCC for out-of-tolerance conditions down to 1.0 V and asserts RST/RST during brownout, manual reset, or watchdog timeout. Used in industrial controllers and embedded systems requiring reliable power-on reset and early power-fail warning.

For engineers reviewing the STM708SDS6E datasheet, STM708SDS6E pinout, STM708SDS6E application, or STM708SDS6E equivalent, key selection criteria include dual reset polarity support, guaranteed reset assertion below 1.0 V VCC, push-pull PFO/WDO outputs, trec stability over temperature, and compatibility with bi-directional MCU reset pins.

Technical Context

The STM708SDS6E implements independent voltage monitoring paths: one precision comparator for VCC (VRST = 3.00–3.15 V) and another for PFI (VPFI ≈ 1.25 V), each driving dedicated push-pull outputs. Its reset logic guarantees RST low and RST high simultaneously during fault conditions, enabling flexible interface to MCUs with either reset polarity requirement.

Unlike STM706 variants, the STM708SDS6E omits the watchdog input (WDI) and output (WDO), simplifying supervision where watchdog functionality is handled externally. The MR input features an internal 40 kΩ pull-up, supporting direct switch-to-ground connection without external biasing.

Key Specifications

Pinout & Package

STM708SDS6E is housed in an 8-pin TSSOP package (3 mm × 3 mm body, DS suffix), optimized for space-constrained industrial PCBs. Pin numbering follows standard JEDEC TSSOP-8 configuration with pin 1 marked by dot or bevel.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM708TDS6F, STM708SDS6E saves PCB area and improves thermal profile in dense layouts; compared with MAX6326US31D3+, it adds critical dual-reset signaling and early power-fail detection-justifying its use in safety-critical or multi-rail systems.

Availability

STM708SDS6E is available at Aetrix Electronics and suitable for industrial PLCs, medical handhelds, smart energy meters, and automated test equipment requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for STM708SDS6E 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 chips for industrial, automotive, and consumer markets.

The STM70x supervisor family targets embedded systems needing robust, low-power, single-chip power monitoring-designed specifically to replace discrete reset circuits and simplify compliance with IEC 61000-4 immunity standards.

FAQ

Can STM708SDS6E be used with 3.3 V systems?

Yes-its 3.00–3.15 V reset threshold is intentionally set below 3.3 V nominal to accommodate typical ±5% supply tolerance and ensure reliable assertion during 3.3 V rail droop. The device operates correctly across VCC = 2.7 V to 5.5 V, with full specification compliance at 3.0 V.

What is the function of the NC pin (Pin 8)?

Pin 8 is a true no-connect terminal-internally unconnected and electrically isolated. It must remain unconnected on the PCB; routing or soldering to this pin may cause mechanical stress or unintended coupling but has no functional impact on device operation.

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

PFI voltage drop below 1.25 V causes PFO to go low, which can be wired to MR to assert RST/RST. This creates a cascaded early-warning reset path independent of VCC monitoring-enabling controlled shutdown before VCC falls below MCU operational minimum.

Is external capacitor required on MR for noise immunity?

A 0.1 µF capacitor from MR to GND is recommended only in noisy environments or when MR traces exceed 5 cm. The internal 40 kΩ pull-up provides sufficient noise margin for typical short-board connections; adding capacitance increases MR response latency but improves ESD/EMI resilience.