STMicroelectronics STM6779YWB6F

Overview

STM6779YWB6F from STMicroelectronics is a triple ultra-low-voltage supervisor IC with push-button reset, monitoring VCC1 (primary), VCC2 (secondary), and RSTIN (externally adjustable third supply) with factory-trimmed thresholds of 4.63 V to 1.58 V, 3.08 V to 0.79 V, and 0.626 V reference respectively; features open-drain active-low RST output, manual reset (MR), delayed manual reset (MRC), and 13.2/210/900 ms power-up reset delay; used in battery-powered networking equipment and portable embedded systems requiring reliable multi-rail power sequencing.

For engineers reviewing the STM6779YWB6F datasheet, STM6779YWB6F pinout, STM6779YWB6F application, or STM6779YWB6F equivalent, key selection criteria include its SOT23-6 open-drain RST output, dual fixed-threshold voltage monitoring plus adjustable RSTIN input, MRC-capable manual reset delay, 11 µA typical supply current at 3.6 V, and –40 °C to +85 °C industrial temperature range.

Technical Context

The STM6779 implements independent comparator-based monitoring of three voltage rails: VCC1 and VCC2 use factory-programmed fixed reset thresholds, while RSTIN compares against an internal 0.626 V reference via external resistor divider. All comparators feed into a logic-controlled reset generator with guaranteed state retention down to VCC1/VCC2 ≥ 0.8 V.

Its reset assertion is triggered by any monitored rail falling below threshold or MR going low; RST remains asserted for trec (13.2/210/900 ms typ) after all rails recover and MR returns high. The MRC pin enables user-configurable delay (≥6 µs) on MR-initiated reset using an external capacitor to VSS.

Key Specifications

Pinout & Package

SOT23-6 (WB) package: 6-pin surface-mount small outline transistor housing with exposed pad thermal performance suitable for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-supply supervisor applications.

Compared with MAX6369KA29+T and TPS3808G33DBVR, STM6779YWB6F uniquely supports three independent supply monitors with configurable RSTIN and MRC delay in a single SOT23-6 package-enabling consolidated power-good signaling in complex multi-rail embedded systems without external logic.

Availability

STM6779YWB6F is available at Aetrix Electronics and suitable for industrial networking gateways, portable medical monitors, set-top box power management, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM6779YWB6F 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, delivering innovative solutions across automotive, industrial, and consumer markets with strong IP in analog, power, and microcontroller technologies.

The STM67xx family targets ultra-low-voltage, low-quiescent-current power supervision for portable and battery-operated systems, emphasizing precision threshold accuracy, minimal footprint, and robust reset timing control.

FAQ

What is the function of the MRC pin on STM6779YWB6F?

The MRC (Manual Reset Delay) pin accepts an external capacitor connected to VSS to introduce a user-defined delay (≥6 µs) between MR assertion and RST activation. This prevents false resets caused by mechanical switch bounce or noise on the MR line. Leaving MRC unconnected results in immediate RST response to MR transitions.

Can STM6779YWB6F monitor a 1.0 V supply rail?

Yes. The RSTIN pin uses an internal 0.626 V reference, enabling monitoring of supplies as low as ~0.63 V via external resistor divider. For a 1.0 V rail, a divider ratio of approximately 1.59:1 (e.g., 159 kΩ top, 100 kΩ bottom) sets the trip point precisely at 1.0 V, verified across –40 °C to +85 °C.

Why does STM6779YWB6F use an open-drain RST output instead of push-pull?

The open-drain RST output allows direct connection to processors with bi-directional reset I/O pins without logic contention. It eliminates the need for external isolation components like resistors or MOSFETs when sharing the reset line among multiple devices, simplifying system-level reset architecture in multi-chip platforms.

How does STM6779YWB6F ensure valid reset behavior during power ramp-up?

STM6779YWB6F guarantees correct RST logic state (high-impedance or pulled high externally) whenever VCC1 or VCC2 exceeds 0.8 V. Its internal bandgap reference and comparators remain functional down to this level, ensuring deterministic reset assertion before the host processor reaches operational voltage-critical for reliable cold-start sequences.