STMicroelectronics STM6904SYEDS6F

Overview

STM6904SYEDS6F from STMicroelectronics is a quad ultralow-voltage supervisor IC for multi-rail power monitoring in embedded systems, featuring factory-programmed reset thresholds of 2.955 V (VCC) and 2.188 V (V2IN), 210 ms reset timeout (tREC), 0.6 V internal reference for adjustable V3IN/V4IN inputs, and open-drain RST output guaranteed active down to VCC = 0.8 V.

For engineers reviewing the STM6904SYEDS6F datasheet, STM6904SYEDS6F pinout, STM6904SYEDS6F application, or STM6904SYEDS6F equivalent, this device supports precise voltage supervision across four rails with ±1.8% threshold accuracy over –40 to +85 °C, manual push-button reset (MR), and TRSEL-configurable tREC timing - critical for reliable boot sequencing in set-top boxes and multi-voltage industrial controllers.

Technical Context

The STM6904SYEDS6F integrates four independent voltage comparators: two with factory-trimmed thresholds (VCC at 2.955 V, V2IN at 2.188 V), and two using an internal 600 mV reference with external resistor dividers on V3IN/V4IN. All comparators feed into a shared reset logic block that asserts RST low if any monitored rail falls below its threshold or MR is pulled low.

Reset assertion is sustained for tREC (210 ms when TRSEL = VSS) after all voltages recover and MR returns high; RST remains functional even at VCC ≥ 0.8 V, enabling supervision during brown-out conditions. The 12 µA typical supply current and 8-pin MSOP/TSSOP package support space-constrained, low-power applications requiring deterministic power-on reset behavior.

Key Specifications

Pinout & Package

STM6904SYEDS6F is housed in an 8-pin MSOP/TSSOP package (3 mm × 3 mm, 0.65 mm pitch), RoHS-compliant and ECOPACK® certified, suitable for automated SMT assembly and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6812HEUS+T and TPS3808G33DBVR, STM6904SYEDS6F uniquely delivers factory-matched dual fixed thresholds plus two scalable inputs in one 8-pin package - reducing component count, PCB area, and qualification effort for multi-rail systems requiring precise, deterministic reset coordination.

Availability

STM6904SYEDS6F is available at Aetrix Electronics and suitable for set-top boxes, multi-voltage industrial controllers, cable/satellite equipment, and data storage systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STM6904SYEDS6F 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, low-power multi-rail monitoring in cost-sensitive, space-constrained embedded systems operating across industrial temperature ranges.

FAQ

What is the exact reset threshold voltage for VCC on STM6904SYEDS6F?

The VCC reset threshold is 2.955 V (typical, falling edge) at 25 °C, with ±1.8% accuracy over –40 to +85 °C. This value is factory-trimmed and fixed per the SY suffix code; it is not user-adjustable. The actual trip point falls between 2.902 V (min) and 3.008 V (max) across temperature and process variation.

Can V3IN and V4IN monitor voltages below 0.6 V?

No. V3IN and V4IN are designed to trigger when the input voltage falls below the internal 600 mV reference; they cannot reliably detect undervoltage conditions below this level. The comparator architecture requires the monitored rail to be scaled upward via external resistor dividers so that 0.6 V corresponds to the desired trip point (e.g., a 1.2 V rail uses a 1:1 divider, a 3.3 V rail uses ~5.5:1).

Is the RST output compatible with 5 V logic systems when VCC = 3.3 V?

Yes. RST is open-drain with no internal level-shifting; it requires an external pull-up resistor to the target logic rail (e.g., 5 V). When VCC = 3.3 V, the output low voltage remains ≤0.3 V for sink currents up to 1.2 mA, ensuring valid logic-low recognition by 5 V CMOS inputs. No additional buffering is needed.

How does TRSEL affect tREC, and what happens if left floating?

TRSEL selects tREC: tied to VSS yields 210 ms, tied to VCC yields 420 ms. If left floating, the pin's undefined state may cause inconsistent tREC timing or metastability in the internal selector logic, risking unreliable reset duration. STMicroelectronics explicitly requires TRSEL to be hard-wired to either VSS or VCC - never left unconnected.