STMicroelectronics STM6905PWEDS6F

Overview

STM6905PWEDS6F 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-two factory-trimmed (VCC = 2.866 V, V2IN = 1.683 V), three externally adjustable via 600 mV internal reference-and asserts an open-drain RST output when any falls below threshold. Its 210 ms power-on reset delay, 12 µA supply current, and operation down to 0.8 V support battery-powered set-top boxes and cable modem power sequencing.

For engineers reviewing the STM6905PWEDS6F datasheet, STM6905PWEDS6F pinout, STM6905PWEDS6F application, or STM6905PWEDS6F equivalent, key selection criteria include fixed dual-threshold accuracy (±1.8 % over –40 °C to +85 °C), MR input with 10 kΩ internal pull-up, RST validity at VCC ≥ 0.8 V, and compatibility with TSSOP8 PCB layouts requiring minimal external components.

Technical Context

The STM6905PWEDS6F implements five independent voltage comparators: two precision bandgap-based monitors for VCC and V2IN with factory-programmed thresholds (2.866 V and 1.683 V), and three high-impedance inputs (V3IN/V4IN/V5IN) referenced to a 600 mV internal reference. All comparators feed into a logic OR gate that triggers RST assertion.

Reset assertion is sustained for a guaranteed 210 ms (tREC) after all monitored supplies exceed their thresholds and MR returns high; the MR input includes built-in noise immunity and requires no external debounce under standard conditions. The open-drain RST output supports flexible pull-up configurations and remains valid even during brownout conditions where VCC drops to 0.8 V.

Key Specifications

Pinout & Package

STM6905PWEDS6F is housed in an 8-pin MSOP/TSSOP package (3 mm × 3 mm, DS suffix), RoHS-compliant and ECOPACK®-qualified, with thermal resistance θ_JA = 146 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6905PWEDS6F, TZEDS6F raises both fixed thresholds for higher-voltage systems, while SYEDS6F offers intermediate values-neither changes pinout, tREC, or adjustable input capability, making them drop-in replacements only when voltage thresholds align with target rail tolerances.

Availability

STM6905PWEDS6F is available at Aetrix Electronics and suitable for set-top boxes, cable/satellite equipment, and multi-voltage industrial controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM6905PWEDS6F 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, specializing in automotive, industrial, and power management solutions with strong analog and mixed-signal IP.

The STM6905 belongs to ST's supervisor IC product line, engineered specifically for robust, low-power, multi-rail voltage monitoring in consumer and industrial electronics where reliability and small footprint are critical.

FAQ

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

The RST output is guaranteed functional down to VCC = 0.8 V, meaning it can assert and maintain reset state even during severe brownout conditions. This is enabled by internal low-voltage biasing circuits and does not require external support components. The 0.8 V specification is tested and guaranteed across the full –40 °C to +85 °C operating range per datasheet Section 6 (DC and AC parameters, VOL test condition).

How do I configure the adjustable thresholds for V3IN, V4IN, and V5IN?

Each adjustable input uses the internal 600 mV reference and a high-impedance comparator. To set a trip voltage VTRIP, connect a resistor divider between the supply rail and ground, with the midpoint feeding the input pin. Use the formula VTRIP = 600 mV × (R1 + R2)/R2, where R1 is upper resistor and R2 is lower resistor. Datasheet Figure 4 shows typical hookup; Table 4 specifies V3IN/V4IN/V5IN input current ≤ ±25 nA, confirming negligible loading effect.

Does the MR input require external pull-up or debounce circuitry?

No external pull-up or debounce is required: the MR pin has a factory-trimmed 10 kΩ internal pull-up to VCC (confirmed in Table 2 and Section 2.1). It accepts direct connection to a momentary switch between MR and VSS. For noisy environments or long traces, a 0.1 µF capacitor from MR to VSS adds immunity-this is optional, not mandatory-and is explicitly noted in the datasheet as supplemental, not fundamental, to basic operation.

Can STM6905PWEDS6F replace a dual-supervisor IC in existing designs?

Yes-its two fixed thresholds (2.866 V and 1.683 V) match common dual-rail requirements (e.g., CPU core + I/O voltage), while the three adjustable inputs provide headroom for future expansion. Pin-compatible with other STM6905 variants in TSSOP8, it requires no layout change. However, verify that existing RST pull-up value (typically 10 kΩ) and MR switch interface remain compatible, as electrical behavior is identical across the family.