STMicroelectronics STM6777SYWB6F

Overview

STM6777SYWB6F from STMicroelectronics is a dual ultra-low-voltage supervisor IC with push-button reset, primary/secondary supply monitoring (VCC1/VCC2), active-low open-drain RST output, manual reset (MR), and delayed manual reset (MRC) input. It features factory-programmed reset thresholds (4.63 V to 1.58 V on VCC1; 3.08 V to 0.79 V on VCC2), 11 µA typical supply current at 3.6 V, and 13.2/210/900 ms selectable power-up reset delay. Used in battery-powered networking equipment for reliable power-on sequencing and fault-triggered system reset.

For engineers reviewing the STM6777SYWB6F datasheet, STM6777SYWB6F pinout, STM6777SYWB6F application, or STM6777SYWB6F equivalent, key selection criteria include dual-supply threshold flexibility, MRC-based manual reset delay tuning, guaranteed RST state down to 0.8 V VCC1/VCC2, and SOT23-6 open-drain output compatibility with microprocessor reset interfaces.

Technical Context

The device implements independent voltage comparators for VCC1 and VCC2, each with factory-trimmed thresholds, plus an external RSTIN comparator referenced to a 0.626 V internal bandgap. Reset assertion occurs if any monitored voltage falls below its threshold or MR is pulled low.

Reset release is synchronized to trec delay after all supplies recover and MR returns high; MRC enables user-configurable delay (≥6 µs) on MR assertion via external capacitor. RST output remains valid (low) as long as VCC1 or VCC2 ≥ 0.8 V, supporting robust operation during brownout conditions.

Key Specifications

Pinout & Package

SOT23-6 (WB) package - 6-pin surface-mount small outline transistor housing with gull-wing leads, 1.3 mm max height, and 0.95 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G18DBVR and MAX6369KA29+T, STM6777SYWB6F uniquely delivers dual independent supply monitoring, configurable manual reset delay via MRC, and open-drain RST-making it the only option among the three that supports complex multi-rail sequencing with glitch-immune human interface.

Availability

STM6777SYWB6F is available at Aetrix Electronics and suitable for industrial IoT sensor nodes, network router management cards, medical portable diagnostic devices, and set-top box power sequencing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for STM6777SYWB6F 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

STM67xx is ST's ultra-low-power dual/triple voltage supervisor product line, engineered specifically for battery-constrained and multi-rail embedded systems requiring precise, low-IQ power monitoring and robust reset control.

FAQ

What is the function of the MRC pin on STM6777SYWB6F?

The MRC (Manual Reset Delay) pin accepts an external capacitor connected to VSS to introduce a user-defined delay between MR assertion and RST activation. With no capacitor, delay is ≥6 µs; a 3.3 µF capacitor yields ~4 s delay. This prevents spurious resets from momentary button presses or noise, and is exclusive to STM6777/78/79/80 variants.

Can STM6777SYWB6F monitor a 1.2 V supply?

Yes-VCC2 supports factory-programmed thresholds down to 0.79 V, covering 1.2 V monitoring. For sub-0.79 V rails, use the RSTIN pin with a resistor divider referenced to the 0.626 V internal comparator-e.g., a 1.2 V rail maps to ~1.9× divider ratio (R1/R2 ≈ 0.9) to scale input to 0.626 V.

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

Yes-STM6777SYWB6F features an active-low open-drain RST output, which requires an external pull-up resistor to VCC1. A 10 kΩ resistor is recommended for most applications. Without it, RST cannot drive high, breaking reset signaling to processors expecting open-drain compatibility.

How does STM6777SYWB6F ensure reset validity during brownout?

The device guarantees correct RST logic state (low when asserted) as long as VCC1 or VCC2 ≥ 0.8 V. This is achieved through internal biasing and comparator design-ensuring reset remains active even as supplies sag below nominal levels, unlike supervisors requiring >1.5 V to maintain output integrity.