STMicroelectronics STM6778TGWB6F

Overview

STM6778TGWB6F from STMicroelectronics is a dual ultra-low-voltage supervisor IC with push-button reset and factory-programmed reset thresholds (VCC1 = 2.93 V, VCC2 = 1.68 V), active-low push-pull RST output, manual reset (MR) input, and delayed manual reset (MRC) pin. It monitors primary and secondary supply rails in battery-powered embedded systems and guarantees valid reset state down to VCC ≥ 0.8 V.

For engineers reviewing the STM6778TGWB6F datasheet, STM6778TGWB6F pinout, STM6778TGWB6F application, or STM6778TGWB6F equivalent, key selection criteria include dual-supply monitoring capability, MRC-based manual reset delay tuning, guaranteed RST behavior at low VCC, and SOT23-6 package compatibility with space-constrained PCB layouts.

Technical Context

This device implements independent voltage comparators for VCC1 and VCC2, each with factory-trimmed thresholds, plus logic that asserts RST low when either supply falls below its threshold or MR is pulled low. The MRC pin enables user-configurable delay (≥6 µs) before RST responds to MR assertion via external capacitor timing.

RST is a push-pull output referenced to VCC1 and remains asserted for trec (13.2 ms / 210 ms / 900 ms typ) after all monitored supplies recover and MR returns high. Internal 50 kΩ pull-up on MR supports direct switch connection without external biasing.

Key Specifications

Pinout & Package

SOT23-6 (WB) package: 6-pin surface-mount, 1.3 mm × 2.9 mm footprint, 1.45 mm height, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6778TGWB6F, STM6778TGWY6F sacrifices VCC2 monitoring and MRC functionality for smaller footprint, while MAX6326UT29D3+T offers single-rail simplicity but cannot replace dual-supply supervision or programmable MR delay in systems requiring those features.

Availability

STM6778TGWB6F is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, set-top box power management, and wireless sensor nodes requiring stable component supply across extended production lifecycles.

Supply support for STM6778TGWB6F 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 devices for industrial, automotive, and consumer markets.

STM67xx is ST's ultra-low-voltage supervisor product line targeting battery-powered and space-constrained embedded systems requiring dual-rail monitoring, push-button reset, and guaranteed reset behavior at sub-1 V supply levels.

FAQ

What is the function of the MRC pin on STM6778TGWB6F?

The MRC (Manual Reset Control) pin enables user-configurable delay between MR assertion and RST activation. Connecting an external capacitor from MRC to VSS sets the delay duration-e.g., a 3.3 µF capacitor yields ~4 s delay. This prevents spurious resets from mechanical switch bounce or transient noise on the MR line.

Can STM6778TGWB6F monitor a 1.2 V supply rail?

No-STM6778TGWB6F has factory-programmed VCC1 and VCC2 thresholds (2.93 V and 1.68 V respectively) and does not support adjustable thresholds for VCC1/VCC2. To monitor 1.2 V, use the RSTIN pin with an external resistor divider referenced to the 0.626 V internal reference, but note RSTIN is not available on STM6778 (only on STM6779/80).

Is the RST output compatible with 5 V logic systems?

Yes-the RST output is push-pull and referenced to VCC1. When VCC1 = 5 V, RST swings fully from near 0 V to near 5 V. However, absolute maximum VCC1 rating is 7.0 V, and operating range is 0.8–5.5 V per datasheet, so 5 V operation is within specification and safe for standard TTL/CMOS interfaces.

How does STM6778TGWB6F ensure reset validity during power ramp-down?

STM6778TGWB6F guarantees correct RST logic state (low during fault, high otherwise) whenever VCC1 or VCC2 ≥ 0.8 V. Below 0.8 V, internal circuitry may become undefined-but since most processors require reset assertion until VCC drops below ~0.5 V, this guarantee covers the critical transition window where reset integrity matters most.