STMicroelectronics STM6778TZWB6F

Overview

STM6778TZWB6F from STMicroelectronics is a dual ultra-low voltage supervisor IC with push-button reset and factory-programmed delay option, monitoring primary supply (VCC1) at 2.93 V and secondary supply (VCC2) at 1.58 V, featuring active-low push-pull RST output, manual reset (MR), delayed manual reset (MRC), and guaranteed reset state down to VCC ≥ 0.8 V - used in battery-powered networking equipment for reliable power-on and brownout detection.

For engineers reviewing the STM6778TZWB6F datasheet, STM6778TZWB6F pinout, STM6778TZWB6F application, or STM6778TZWB6F equivalent, this page delivers verified pin functions, exact reset thresholds, MRC capacitor timing behavior, industrial-grade temperature operation (–40 °C to +85 °C), and direct substitution guidance for dual-supply supervision in space-constrained embedded systems.

Technical Context

The STM6778TZWB6F implements independent comparator-based monitoring of VCC1 and VCC2 against factory-trimmed thresholds (2.93 V and 1.58 V respectively), with logic-gated reset assertion that holds RST low until both supplies exceed thresholds and MR returns high. Its internal trec generator provides fixed 13.2 ms, 210 ms, or 900 ms reset timeout after recovery.

It integrates an MRC pin enabling user-configurable manual reset delay via external capacitor (e.g., 3.3 µF yields ~4 s delay), while maintaining guaranteed RST logic state when VCC1 or VCC2 ≥ 0.8 V - critical for sequencing integrity during deep brownout conditions in portable communication devices.

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 supervision applications.

Compared with STM6777TZWB6F, the STM6778TZWB6F adds MRC-based delay programmability without sacrificing pin compatibility or threshold accuracy; versus TPS3808G33DBVR, it trades 8.5 µA higher ICC for dual-rail coverage and hardware-debounced reset control - making it optimal for compact, multi-rail embedded systems requiring deterministic manual intervention.

Availability

STM6778TZWB6F is available at Aetrix Electronics and suitable for industrial Ethernet switches, portable VoIP phones, set-top boxes, and wireless gateways requiring stable component supply with guaranteed long-term availability and full traceability.

Supply support for STM6778TZWB6F 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.

The STM67xx family targets ultra-low-voltage, low-quiescent-current supervision in space-constrained portable and networking equipment - emphasizing factory-trimmed precision, guaranteed low-VCC operation, and flexible reset initiation methods.

FAQ

What is the factory-programmed reset threshold for VCC1 on STM6778TZWB6F?

The VCC1 reset threshold is factory-programmed to 2.93 V ±1.5%, measured at TA = 25 °C and confirmed across –40 °C to +85 °C with <±0.5% drift. This value is laser-trimmed during production and cannot be adjusted externally - it directly supervises standard 3.3 V system rails.

Can the MRC pin be left unconnected, and what happens to manual reset behavior?

Yes, the MRC pin may be left open (unconnected), resulting in minimum manual reset delay of 6 µs after MR assertion. In this configuration, the device behaves identically to STM6777TZWB6F - delivering immediate RST assertion upon MR low-to-high transition, with no added timing uncertainty.

Is the RST output compatible with 1.8 V I/O logic without level shifting?

No - the RST output is push-pull referenced to VCC1, so its high-level voltage equals VCC1 (e.g., 3.3 V). Driving a 1.8 V logic input requires a series resistor (e.g., 10 kΩ) or level-shifter; direct connection risks overvoltage damage to 1.8 V receivers unless VCC1 ≤ 1.8 V (not supported per absolute max rating).

Does STM6778TZWB6F support monitoring of a 0.9 V core supply?

No - the device does not include RSTIN functionality (available only on STM6779/80). It monitors only VCC1 and VCC2 with fixed thresholds (2.93 V and 1.58 V). To supervise sub-1 V rails, use STM6779TZWB6F or STM6780TZWB6F with external resistor divider on RSTIN referenced to 0.626 V internal bandgap.