STMicroelectronics STM6780LWB6F

Overview

STM6780LWB6F from STMicroelectronics is a triple ultra-low-voltage supervisor IC with push-button reset and programmable manual reset delay, 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; it delivers active-low push-pull RST output, 13.2/210/900 ms power-up reset delay options, and 11 µA typical supply current at 3.6 V - deployed in battery-powered networking equipment and industrial embedded controllers.

For engineers reviewing the STM6780LWB6F datasheet, STM6780LWB6F pinout, STM6780LWB6F application, or STM6780LWB6F equivalent, key selection criteria include triple-supply monitoring capability, MRC-capable delayed manual reset timing (up to seconds via external capacitor), guaranteed RST state down to VCC1/VCC2 ≥ 0.8 V, and SOT23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The STM6780LWB6F implements three independent voltage comparators: one for VCC1 with factory-programmed threshold (e.g., 2.93 V), one for VCC2 (e.g., 1.68 V), and one for RSTIN referenced to a stable 0.626 V internal bandgap. All comparators feed into a logic-controlled reset generator that enforces minimum trec delay (13.2/210/900 ms typ) before releasing RST after recovery.

Its MRC pin enables user-configurable manual reset delay by connecting an external capacitor to VSS; delay ranges from 6 µs (open) to >4 s (3.3 µF), implemented via RC-based timing without internal oscillator. The push-pull RST output is referenced to VCC1 and remains valid as long as VCC1 or VCC2 ≥ 0.8 V.

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 triple-supply supervisor applications.

Compared with MAX6326US29D3+ and TPS3808G33DBVR, the STM6780LWB6F uniquely supports three independent supply monitors, user-adjustable manual reset delay via MRC, and push-pull RST - making it irreplaceable in compact, multi-rail industrial and medical systems demanding full power-rail visibility and robust reset control.

Availability

STM6780LWB6F is available at Aetrix Electronics and suitable for industrial PLC controllers, 5G small cell baseband units, battery-powered IoT gateways, and medical point-of-care monitors requiring stable component supply across extended product lifecycles.

Supply support for STM6780LWB6F 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-power, multi-rail system supervision in space- and energy-constrained applications - emphasizing factory-trimmed accuracy, guaranteed low-VCC operation, and flexible reset timing for embedded processors.

FAQ

What is the function of the MRC pin on STM6780LWB6F?

The MRC (Manual Reset Delay) pin accepts an external capacitor connected to VSS to delay RST assertion after MR activation. With a 3.3 µF capacitor, delay reaches ~4 s; open circuit yields minimum 6 µs delay. This prevents accidental resets during brief button presses or electrical noise spikes in industrial environments.

Can STM6780LWB6F monitor a 1.2 V supply using RSTIN?

Yes. Using the 0.626 V internal reference, a resistor divider (e.g., R1 = 100 kΩ, R2 = 100 kΩ) sets RSTIN threshold to 1.252 V. When the 1.2 V rail drops below this value, RST asserts. Divider ratio must ensure RSTIN voltage stays within 0.626 V ±10% for reliable detection across temperature.

Is STM6780LWB6F compatible with 1.8 V VCC1 operation?

Yes. STM6780LWB6F operates with VCC1 as low as 0.8 V and supports factory-trimmed thresholds down to 1.58 V. At 1.8 V VCC1, it reliably monitors VCC2 and RSTIN while delivering valid push-pull RST output - confirmed across –40 °C to +85 °C per datasheet Figure 22.

How does STM6780LWB6F ensure reset validity during power-down?

It guarantees correct RST logic state whenever VCC1 or VCC2 ≥ 0.8 V. Unlike open-drain supervisors, its push-pull output actively drives low or high without external components - ensuring clean reset assertion and release even as supplies decay through brown-out zones, critical for fail-safe shutdown in medical devices.