STMicroelectronics STM6519AHARUB6F

Overview

STM6519AHARUB6F from STMicroelectronics is a single-pin, push-button Smart Reset™ supervisor IC designed for delayed, glitch-immune system reset initiation in portable electronics. It features a factory-programmed Smart Reset delay (tSRC) of 4.0 s (typ.), operates from 2.0 V to 5.5 V, draws only 1 µA supply current, and delivers an active-low open-drain reset output (RST) with no fixed pulse width - de-asserting immediately upon SR release. It is used in smartphones and e-readers to distinguish short interrupt presses from long hard resets.

For engineers reviewing the STM6519AHARUB6F datasheet, STM6519AHARUB6F pinout, STM6519AHARUB6F application, or STM6519AHARUB6F equivalent, this page provides verified pin functions, real-world timing behavior (tSRC = 4.0 s, no tREC), UDFN6 package layout, and validated alternatives for push-button reset supervision where extended hold-time discrimination is required.

Technical Context

The STM6519AHARUB6F implements a deterministic digital timer that begins counting only after the SR input is held low for >100 ms (glitch immunity), then asserts RST after exactly 4.0 s (typ.) - with ±20% variation over -40 °C to +85 °C. Its logic threshold on SR is fixed at 0.3 V (low) and 0.85×VCC (high), eliminating external resistor dependency when pull-up is omitted.

No internal voltage monitoring is present (V_RST = none); reset assertion is purely time-based and edge-triggered by SR. The device supports test mode entry via overvoltage (V_TEST ≥ V_CC + 1.1 V), enabling rapid validation using shortened t_SRC-SHORT = t_SRC/128 ≈ 31 ms.

Key Specifications

Pinout & Package

STM6519AHARUB6F uses the UDFN6 (1.00 mm × 1.45 mm) package with exposed thermal pad, RoHS-compliant and halogen-free (ECOPACK®2). Pin 1 is marked by a dot; pins 5 and 6 are not bonded and must be connected to VSS.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar push-button reset supervision applications.

Compared with MAX6326XR29D3+T and TPS3808G33DBVR, STM6519AHARUB6F uniquely integrates push-button debouncing, fixed 4.0 s delay, and zero-external-component operation - delivering lowest BOM count and highest reliability for dedicated timed-reset applications in portable devices.

Availability

STM6519AHARUB6F is available at Aetrix Electronics and suitable for smartphone system recovery, e-reader power management, and portable GPS navigation requiring stable component supply, guaranteed lead times, and long-term lifecycle support.

Supply support for STM6519AHARUB6F 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, specializing in automotive, industrial, and consumer ICs with strong emphasis on power efficiency and system integration.

The STM6519 belongs to ST's Smart Reset™ supervisor product line, engineered specifically for human-interface-driven reset initiation in battery-powered portable electronics - prioritizing ultra-low quiescent current, compact packaging, and deterministic timing behavior.

FAQ

Does STM6519AHARUB6F include VCC monitoring or brown-out detection?

No. STM6519AHARUB6F has no voltage-monitoring function - its reset assertion is solely time-based and triggered by the SR input. The "A" in the part number explicitly denotes absence of VCC threshold monitoring. It relies entirely on external power integrity; system-level brown-out protection must be implemented separately.

What is the exact behavior of the RST output when SR is released before tSRC expires?

RST remains de-asserted (high-Z for open-drain) - no reset pulse is generated. Only after SR is held low continuously for the full 4.0 s (typ.) does RST go low; releasing SR at any point prior aborts the timer and leaves RST inactive. This ensures zero false resets from accidental presses.

Can STM6519AHARUB6F be used with a 1.8 V supply?

No. The absolute minimum operating voltage is 2.0 V per datasheet Section 3 and Table 3. At 1.8 V, internal logic fails to initialize reliably, and tSRC timing becomes undefined. For 1.8 V systems, consider ST's STM6513 series or alternate supervisors rated down to 1.6 V.

Is there an internal pull-up resistor on the SR pin for STM6519AHARUB6F?

No. Per Table 7 (Package Marking Information) and ordering code "HA", this variant has no internal SR pull-up. An external pull-up resistor (typically 10–100 kΩ to VCC) is required unless the push-button directly shorts SR to ground with no floating state.