STMicroelectronics STM6904TWEDS6F

Overview

STM6904TWEDS6F from STMicroelectronics is a quad ultralow-voltage supervisor IC for multi-rail power monitoring in embedded systems, featuring fixed VCC (3.078 V) and V2IN (1.683 V) reset thresholds, two externally adjustable monitor inputs (V3IN/V4IN), 210 ms reset timeout (TRSEL = VSS), and open-drain RST output guaranteed down to VCC ≥ 0.8 V. It supports set-top boxes, cable/satellite receivers, and industrial multi-voltage systems.

For engineers reviewing the STM6904TWEDS6F datasheet, STM6904TWEDS6F pinout, STM6904TWEDS6F application, or STM6904TWEDS6F equivalent, key selection considerations include factory-trimmed dual fixed thresholds, 0.6 V internal reference for adjustable inputs, MR push-button reset with internal 10 kΩ pull-up, tREC selectability, and operation across –40 to 85 °C.

Technical Context

The STM6904TWEDS6F integrates four independent voltage comparators: two with factory-programmed thresholds (VCC = 3.078 V, V2IN = 1.683 V) and two using an internal 0.600 V reference with external resistor dividers for user-defined trip points. All comparators feed into a logic OR gate that asserts RST low on any undervoltage event or MR activation.

Reset assertion is sustained for a minimum tREC delay (210 ms when TRSEL = VSS) after all monitored supplies exceed their thresholds and MR returns high. The device guarantees RST functionality down to VCC = 0.8 V and draws only 12 µA typical supply current, enabling use in battery-sensitive applications.

Key Specifications

Pinout & Package

Package: 8-pin MSOP/TSSOP (3 × 3 mm, ECOPACK® green, RoHS compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6904TZEDS6F and STM6904TGEDS6F, the STM6904TWEDS6F uniquely balances mid-range auxiliary rail supervision (1.683 V) with high-accuracy primary monitoring (3.078 V), making it optimal for 1.8 V/3.3 V dual-core systems where neither higher nor lower V2IN thresholds match the target rail's nominal voltage and tolerance band.

Availability

STM6904TWEDS6F is available at Aetrix Electronics and suitable for set-top boxes, cable/satellite receivers, and industrial multi-voltage systems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for STM6904TWEDS6F 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 components for industrial, automotive, and consumer markets.

The STM6904 belongs to ST's precision voltage supervisor product line, engineered specifically for robust multi-rail power monitoring in cost-sensitive, space-constrained embedded systems operating across industrial temperature ranges.

FAQ

What is the minimum VCC voltage required for RST output functionality?

The STM6904TWEDS6F guarantees RST output assertion and release behavior down to VCC = 0.8 V. Below this, the internal comparators and logic may not operate reliably. This specification is validated per Table 4 in the datasheet (VOL test conditions at VCC ≥ 0.8 V, ISINK = 1 µA), enabling use in brown-out detection for battery-backed systems.

How do I configure V3IN and V4IN for a 2.5 V rail monitor?

To monitor a 2.5 V rail with V3IN, use a resistor divider where VTRIP = 0.600 V = 2.5 V × [R2 / (R1 + R2)]. For example, R1 = 31.6 kΩ and R2 = 10 kΩ yields VTRIP ≈ 2.5 V × 0.24 = 0.600 V. The same formula applies to V4IN. Ensure total divider current remains below 100 nA to avoid loading errors, per I3IN/I4IN specs.

Can TRSEL be left floating to default to 210 ms timeout?

No - TRSEL must be actively tied to either VSS (for 210 ms) or VCC (for 420 ms). Floating TRSEL violates the absolute maximum rating for input voltage (Table 3) and causes undefined tREC behavior. The datasheet explicitly states "Pin must be tied to VCC or VSS (do not float)" in Table 2 and Figure 4 notes.

Is the MR input compatible with 1.8 V logic levels?

Yes - MR is a standard CMOS input with VIH = 0.7 × VCC and VIL = 0.3 × VCC. When VCC = 3.3 V, VIH = 2.31 V, so a 1.8 V logic high does not meet the threshold. However, MR can be driven by open-drain outputs pulled to VCC or directly by a switch to VSS, making it compatible with any system where the reset source references the same VCC rail.