STMicroelectronics STM6519APBBUB6F

Overview

STM6519APBBUB6F from STMicroelectronics is a single-pin Smart Reset™ supervisory IC that implements push-button–triggered, extended-delay reset assertion with factory-programmed 360 ms reset pulse width (tREC) and 7.5 s Smart Reset setup delay (tSRC). It features active-low SR input with internal pull-up resistor, active-low open-drain RST output, operates from 2.0 V to 5.5 V, draws only 1 µA supply current, and is housed in a 1.00 mm × 1.45 mm UDFN6 package for space-constrained portable electronics.

For engineers reviewing the STM6519APBBUB6F datasheet, STM6519APBBUB6F pinout, STM6519APBBUB6F application, or STM6519APBBUB6F equivalent, this device delivers deterministic delayed-reset behavior for handheld systems where accidental short-press resets must be avoided while retaining reliable hard-reset capability via sustained button press.

Technical Context

The STM6519APBBUB6F integrates a precision programmable timer that initiates RST assertion only after the SR input remains low for exactly 7.5 s (typ.), with ±20% variation over –40 °C to +85 °C. Its logic includes dedicated test mode entry via SR overvoltage (VCC + 1.4 V), enabling in-system validation without external equipment.

Reset output behavior is strictly defined by the tREC option: here, RST remains asserted for 360 ms (typ., 240–480 ms min/max) regardless of SR release timing, ensuring consistent processor reset duration. The SR input includes fixed logic thresholds (VIL ≤ 0.3 V, VIH ≥ 0.85 VCC) and optional 65 kΩ internal pull-up - confirmed for this variant ('B' in ordering code).

Key Specifications

Pinout & Package

STM6519APBBUB6F is packaged in a 6-pin UDFN (Ultra Thin Fine Pitch No-lead) package measuring 1.00 mm × 1.45 mm with 0.5 mm pitch, ECOPACK®2-compliant (RoHS, halogen-free), and optimized for high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM6519APARUB6F, this variant adds guaranteed 360 ms reset assertion for robust boot reliability; compared with TPS3808G125DBVR, it provides unique 7.5 s programmable hold-time discrimination - eliminating false resets while ensuring deterministic recovery in portable UIs.

Availability

STM6519APBBUB6F is available at Aetrix Electronics and suitable for smartphone power management, e-reader system recovery, portable GPS navigation units, and MP3 player firmware recovery requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STM6519APBBUB6F 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 automotive, industrial, and consumer markets.

The STM6519 belongs to ST's Smart Reset™ family of supervisory ICs, engineered specifically to replace mechanical reset buttons with intelligent, delay-discriminating push-button interfaces in battery-powered portable electronics.

FAQ

What is the function of the SR pin on STM6519APBBUB6F?

The SR pin is the active-low Smart Reset input with an integrated 65 kΩ pull-up resistor. It initiates the 7.5 s tSRC timer when pulled low and enters test mode if driven above VCC + 1.4 V. Its fixed logic thresholds (VIL ≤ 0.3 V, VIH ≥ 0.85 VCC) ensure noise immunity and compatibility across voltage domains.

Does STM6519APBBUB6F require an external pull-up resistor on the SR pin?

No. The 'B' suffix in the part number explicitly denotes inclusion of an internal 65 kΩ pull-up resistor on the SR input. This eliminates the need for an external component, reducing bill-of-materials count and PCB footprint in space-constrained designs like smartphones and e-readers.

How does the tREC = 360 ms feature improve system reliability?

The factory-programmed 360 ms reset pulse ensures the RST output remains asserted for a guaranteed minimum duration regardless of when the user releases the push button. This meets strict microcontroller reset timing requirements (e.g., ARM boot loaders), preventing partial resets, corrupted memory initialization, or peripheral lockup caused by premature RST de-assertion.

Can STM6519APBBUB6F operate across different voltage domains for SR and VCC?

Yes - its open-drain RST output and fixed SR input thresholds allow operation with SR in a different voltage domain (e.g., VBAT) than VCC. However, VCC must power up before or simultaneously with SR voltage to avoid inadvertent test mode entry (V(SR) > VCC + 1.1 V), as confirmed in ST's application diagrams and timing constraints.