STMicroelectronics STM6905TWEDS6F

Overview

STM6905TWEDS6F from STMicroelectronics is a quintuple ultralow-voltage supervisor IC with push-button reset functionality, designed for multi-rail power monitoring in embedded systems. It monitors one primary supply (VCC) at 3.078 V, a second fixed supply (V2IN) at 1.683 V, and three externally adjustable supplies using a 600 mV internal reference; features ±1.8 % threshold accuracy over temperature, 210 ms reset delay (tREC), and open-drain RST output guaranteed down to VCC = 0.8 V. Used in set-top boxes and multi-voltage industrial systems.

For engineers reviewing the STM6905TWEDS6F datasheet, STM6905TWEDS6F pinout, STM6905TWEDS6F application, or STM6905TWEDS6F equivalent, key selection considerations include factory-trimmed dual fixed thresholds (3.078 V / 1.683 V), 210 ms tREC timing, 12 µA typical supply current, and compatibility with 0.8–5.5 V operation across –40 °C to +85 °C.

Technical Context

The STM6905TWEDS6F implements five independent voltage comparators: two factory-programmed fixed-threshold monitors (VCC at 3.078 V, V2IN at 1.683 V) and three adjustable inputs (V3IN/V4IN/V5IN) referenced to a 600 mV internal bandgap. All comparators feed into a single reset logic block that asserts RST low if any monitored voltage falls below its threshold or MR is pulled low.

Reset assertion includes hysteresis (0.5 % of VRST), glitch immunity on MR (100 ns), and a guaranteed minimum tREC of 210 ms after power-up or MR release. The RST output is open-drain with 0.3 V max VOL at ISINK ≤ 3.2 mA and requires external pull-up; MR includes a 10 kΩ internal pull-up to VCC.

Key Specifications

Pinout & Package

STM6905TWEDS6F is housed in an 8-pin MSOP (TSSOP8) package, 3 mm × 3 mm body, 0.65 mm pitch, RoHS-compliant ECOPACK® green package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6905TWEDS6F, TZEDS6F raises V2IN to 2.333 V for compatibility with 2.5 V rails, while PWEDS6F lowers VCC to 2.866 V for tighter 2.8 V system margins-both retain identical 210 ms tREC, 8-pin TSSOP package, and adjustable V3IN/V4IN/V5IN capability.

Availability

STM6905TWEDS6F is available at Aetrix Electronics and suitable for set-top boxes, multi-voltage embedded systems, cable/satellite equipment, computer systems, and data storage equipment requiring stable component supply across industrial temperature ranges.

Supply support for STM6905TWEDS6F 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The STM6905 product line delivers integrated multi-rail voltage supervision with factory-trimmed precision and ultra-low power consumption, targeting space-constrained, reliability-critical embedded systems requiring deterministic reset behavior.

FAQ

What is the exact reset threshold voltage for V2IN on STM6905TWEDS6F?

The V2IN reset threshold is factory-programmed to 1.683 V, with ±1.8 % accuracy across –40 °C to +85 °C. This value is confirmed in Table 1 and Table 4 of the official ST datasheet DocID14290 Rev 4, and corresponds to the "W" suffix in the ordering code. No external adjustment is possible for V2IN-it is fixed at this value for this specific part number.

Can STM6905TWEDS6F monitor a 1.0 V supply rail?

Yes-STM6905TWEDS6F can monitor a 1.0 V rail using any of the three adjustable inputs (V3IN, V4IN, or V5IN). By connecting a resistor divider between the 1.0 V rail and ground, the voltage at the input pin is scaled down to match the 600 mV internal reference. For example, a 1.0 V rail requires a divider ratio of 1.0 V / 0.6 V ≈ 1.67, achievable with standard resistor values such as 68 kΩ (top) and 100 kΩ (bottom).

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

Yes-an external pull-up resistor is mandatory on the RST pin because it is an open-drain output. ST recommends a 10 kΩ resistor to VCC for most applications. The internal 10 kΩ pull-up on MR does not apply to RST; without external pull-up, RST cannot assert a valid high level, breaking reset signaling to downstream logic or processors.

Does STM6905TWEDS6F support manual reset deassertion before tREC completes?

No-once triggered by MR, RST remains low for the full tREC period (210 ms typ) after MR returns high, regardless of supply status. This is a hardwired timing behavior per the functional block diagram and Figure 5 (MR timing waveforms) in the datasheet. The tREC timer resets only upon MR release and starts counting anew; it cannot be shortened or bypassed by supply recovery alone.