STMicroelectronics STM706PDS6F

Overview

STM706PDS6F from STMicroelectronics is a 3 V precision voltage supervisor IC with active-high reset output, designed for microprocessor reset management in embedded systems. It features a 2.59–2.70 V reset threshold (R), 200 ms reset timeout (t_rec), 1.6 s watchdog timer, power-fail comparator (PFI/PFO), and operates from –40 °C to +85 °C. Used in industrial controllers and intelligent instrumentation where reliable power-on reset and brownout detection are critical.

For engineers reviewing the STM706PDS6F datasheet, STM706PDS6F pinout, STM706PDS6F application, or STM706PDS6F equivalent, key selection criteria include reset polarity (active-high RST), V_RST tolerance band, guaranteed reset assertion down to V_CC = 1.0 V, and compatibility with manual reset (MR) and watchdog (WDI/WDO) interfaces in space-constrained TSSOP8 layouts.

Technical Context

The STM706PDS6F integrates a precision bandgap reference, dual comparators (V_RST and V_PFI), a 1.6 s monostable watchdog timer, and push-pull RST/RST outputs. Its reset logic guarantees active-high assertion for V_CC < 2.59 V and holds RST high for ≥200 ms after V_CC recovery - independent of MR or WDI activity.

It supports three supervisory functions simultaneously: power-on/brownout reset via V_CC monitoring, system-level watchdog supervision (WDI edge-triggered, WDO push-pull), and early power-fail warning (PFI threshold = 1.25 V ±1.5%, PFO push-pull). All logic inputs (MR, WDI) tolerate TTL/CMOS levels and include internal pull-ups.

Key Specifications

Pinout & Package

STM706PDS6F is housed in an 8-pin TSSOP package (3 mm × 3 mm body, DS suffix), optimized for high-density PCB layouts. Pin numbering follows standard JEDEC TSSOP8 orientation (pin 1 marked).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM706RDS6F, STM706PDS6F eliminates level-shifting overhead for active-high-reset MCUs; compared with MAX6326US26D3+, it adds watchdog and power-fail capability at minimal board-area cost in TSSOP8.

Availability

STM706PDS6F is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, medical handheld diagnostics, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM706PDS6F 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 STM70x supervisor family targets embedded systems requiring deterministic reset behavior, fail-safe watchdog supervision, and multi-rail power monitoring - with STM706P optimized for active-high reset architectures in compact TSSOP8 layouts.

FAQ

What is the function of the PFI and PFO pins on STM706PDS6F?

PFI is an analog input referenced to a dedicated 1.25 V internal comparator; when voltage at PFI falls below this threshold, PFO (a push-pull output) asserts low. This provides early warning of impending power failure - typically implemented using a resistor divider from an unregulated supply rail. PFO can be connected to MR to trigger a system reset before V_CC drops below the 2.59 V reset threshold.

Can the watchdog timer be disabled on STM706PDS6F?

Yes, the watchdog timer is disabled when the WDI pin is left floating or tri-stated. The datasheet specifies maximum leakage current of 10 µA and load capacitance of 200 pF under this condition. No configuration register or external component is required - simply omit the MCU connection to WDI or configure the driving GPIO as high-impedance.

How does STM706PDS6F ensure reset validity down to V_CC = 1.0 V?

The internal reset circuitry remains functional and guarantees RST remains high for V_CC ≥ 1.0 V across –40 °C to +85 °C. Below 1.0 V, RST becomes high-impedance; a 100 kΩ pull-down resistor on the RST pin ensures it defaults low during deep undervoltage, preventing floating states that could cause MCU latch-up or erratic behavior.

Is STM706PDS6F pin-compatible with other STM706 variants in TSSOP8?

Yes - all STM706x variants (T/S/R/P) share identical TSSOP8 pinouts and footprints. The only functional differences are V_RST thresholds and RST/RST polarity. For example, STM706PDS6F (active-high RST) and STM706RDS6F (active-low RST) are hardware-swappable; software or MCU reset-polarity configuration may require adjustment.