STMicroelectronics STM6905SFEDS6F

Overview

STM6905SFEDS6F from STMicroelectronics is a quintuple ultralow-voltage supervisor IC with push-button reset functionality, designed for multi-rail power monitoring in industrial embedded systems. It monitors five supply rails-VCC (fixed 2.955 V threshold), V2IN (fixed 1.050 V threshold), and three externally adjustable inputs (V3IN/V4IN/V5IN) referenced to a 600 mV internal reference-with ±1.8% voltage threshold accuracy across –40 °C to +85 °C and 210 ms typical power-on reset delay (tREC).

For engineers reviewing the STM6905SFEDS6F datasheet, STM6905SFEDS6F pinout, STM6905SFEDS6F application, or STM6905SFEDS6F equivalent, this device supports precise, low-current (12 µA typ) supervision of heterogeneous voltage domains in space-constrained set-top boxes, cable/satellite receivers, and multi-voltage computer systems requiring guaranteed RST assertion down to VCC ≥ 0.8 V.

Technical Context

The STM6905SFEDS6F implements five independent voltage comparators: two factory-trimmed fixed-threshold monitors (VCC at 2.955 V, V2IN at 1.050 V) and three adjustable inputs using an internal 600 mV reference with external resistor dividers. Its logic diagram integrates a tREC timer that holds RST low until all monitored supplies exceed their thresholds and MR returns high.

It features an active-low open-drain RST output with guaranteed operation down to VCC = 0.8 V, a manual reset input (MR) with 10 kΩ internal pull-up, and hysteresis of 0.5% on fixed thresholds. The device operates across 0.8–5.5 V supply range and consumes only 12 µA typical supply current.

Key Specifications

Pinout & Package

STM6905SFEDS6F is housed in an 8-pin MSOP (TSSOP8) package, 3 mm × 3 mm body size, RoHS-compliant and ECOPACK®-certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6905SYEDS6F and STM6905TZEDS6F, the STM6905SFEDS6F uniquely supports critical low-voltage domains (e.g., 1.05 V I/O) while retaining compatibility with standard 2.955 V core rails-enabling direct replacement in next-gen compact systems where secondary rail voltage has been scaled downward.

Availability

STM6905SFEDS6F is available at Aetrix Electronics and suitable for set-top boxes, cable/satellite receivers, and multi-voltage computer systems requiring stable component supply, long-term industrial-grade availability, and RoHS-compliant packaging.

Supply support for STM6905SFEDS6F 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, delivering innovative solutions across automotive, industrial, power, and microcontroller markets.

The STM6905 product line delivers highly integrated, low-power voltage supervisors targeting multi-rail embedded systems where space, accuracy, and reliability are critical-designed specifically for set-top boxes, networking gear, and industrial computing platforms.

FAQ

What is the exact reset threshold voltage for V2IN on STM6905SFEDS6F?

The V2IN reset threshold for STM6905SFEDS6F is factory-programmed to 1.050 V (typical) with ±1.8% accuracy across –40 °C to +85 °C, as confirmed in Table 1 and Table 4 of the official ST datasheet DocID14290 Rev 4. This value is fixed and non-adjustable, unlike the V3IN/V4IN/V5IN inputs.

Can STM6905SFEDS6F monitor a 1.2 V supply using its adjustable inputs?

Yes-V3IN, V4IN, and V5IN accept externally adjustable thresholds via resistor dividers referenced to the internal 600 mV reference. To monitor a 1.2 V rail, use a resistor network where VTRIP = 1.2 V = 600 mV × (R1 + R2)/R2, yielding R1/R2 ≈ 1.0. This configuration is validated in Figure 4 and Section 3.1 of the datasheet.

Does the RST output remain functional when VCC drops below 1.0 V?

Yes-the RST output is guaranteed active for VCC ≥ 0.8 V, as specified in the Features list and Section 1 (Description). This allows reliable reset assertion during brown-out conditions where VCC sags to 0.8–0.9 V, a key differentiator versus supervisors requiring ≥1.2 V for RST validity.

Is an external pull-up resistor required on the RST pin?

Yes-an external pull-up resistor to VCC is mandatory because RST is an open-drain output. ST recommends a 10 kΩ resistor (per Section 2.6 and Figure 4), which ensures proper logic-high level and noise immunity while limiting current draw during reset assertion.