STMicroelectronics STM6904TZEDS6F

Overview

STM6904TZEDS6F from STMicroelectronics is a quad ultralow-voltage supervisor IC with push-button reset, monitoring four supply rails: fixed VCC (3.078 V), fixed V2IN (2.333 V), and two externally adjustable inputs (V3IN/V4IN) referenced to 0.6 V internal reference. It delivers open-drain RST output guaranteed active down to VCC ≥ 0.8 V, 210 ms reset timeout (TRSEL = VSS), and 12 µA typical supply current - deployed in multi-rail set-top boxes and cable/satellite systems.

For engineers reviewing the STM6904TZEDS6F datasheet, STM6904TZEDS6F pinout, STM6904TZEDS6F application, or STM6904TZEDS6F equivalent, key selection criteria include factory-trimmed dual fixed thresholds, resistor-divider programmability for two additional rails, MR input with 10 kΩ internal pull-up, tREC selectability, and industrial-grade operation from –40 °C to +85 °C in MSOP8.

Technical Context

The device integrates four independent voltage comparators: two with factory-programmed thresholds (VCC at 3.078 V ±1.8%, V2IN at 2.333 V ±1.8%) and two using an internal 0.600 V reference to sense externally scaled inputs via resistor dividers. All comparators feed into a reset logic block that asserts RST low if any monitored rail falls below its threshold or MR is pulled low.

RST remains asserted for tREC (210 ms or 420 ms) after all voltages recover and MR returns high; TRSEL pin selects timing by hardwiring to VSS or VCC. The open-drain RST output supports 10 kΩ external pull-up and guarantees valid state down to VCC = 0.8 V, enabling reliable reset assertion during brownout conditions.

Key Specifications

Pinout & Package

Package: MSOP8 (TSSOP8), 3 mm × 3 mm, 0.65 mm pitch, RoHS-compliant green package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3307-33D and MAX6816CUA+, STM6904TZEDS6F uniquely combines factory-trimmed dual thresholds, two resistor-adjustable inputs, MR with internal pull-up, and tREC selectability - making it the only option supporting full four-rail supervision with push-button control in compact MSOP8.

Availability

STM6904TZEDS6F is available at Aetrix Electronics and suitable for set-top boxes, cable/satellite equipment, and multi-voltage computer systems requiring stable component supply, long-term industrial temperature support, and RoHS-compliant packaging.

Supply support for STM6904TZEDS6F 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.

STM6904 belongs to ST's supervisor IC product line, engineered specifically for robust multi-rail power monitoring in consumer broadband and embedded computing systems where reliability, precision, and compact packaging are critical.

FAQ

What is the minimum VCC voltage required for valid RST output assertion?

The STM6904TZEDS6F guarantees correct RST logic state (active-low assertion) down to VCC = 0.8 V. Below this, the internal circuitry cannot maintain comparator bias or output driver functionality. This enables reliable reset generation during deep brownout conditions common in unregulated or battery-depleted systems.

How do I configure V3IN and V4IN for a 2.0 V threshold?

Use the formula VTRIP = 0.6 V × (R1 + R2)/R2, where VTRIP = 2.0 V. Solving yields R1/R2 ≈ 2.33. Select standard resistors (e.g., R1 = 233 kΩ, R2 = 100 kΩ) to achieve 2.0 V trip point. Connect R1 between the 2.0 V rail and V3IN/V4IN, and R2 between that pin and VSS.

Can TRSEL be left floating to default to 210 ms?

No - TRSEL must be hardwired to either VSS (for 210 ms) or VCC (for 420 ms). Floating TRSEL causes undefined tREC behavior and may result in inconsistent reset timing or device malfunction. The datasheet explicitly prohibits floating this pin.

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

Yes - RST is open-drain and requires an external pull-up resistor to VCC. A 10 kΩ resistor is recommended and sufficient for most applications. Without it, RST cannot drive high-impedance or logic-high states, breaking reset coordination with downstream processors or FPGAs.