STMicroelectronics STM6505WCABDG6F

Overview

STM6505WCABDG6F from STMicroelectronics is a dual push-button Smart Reset IC with user-adjustable setup delay, battery voltage monitoring (VBAT), and independent low-battery detect output (BLD). It features factory-programmable VCC reset thresholds (1.575–4.625 V), 2 mm × 2 mm TDFN8 package, -40 °C to +85 °C industrial temperature range, and open-drain RST/BLD outputs. Used in smartphones and portable navigation devices for robust power-up sequencing and battery health indication.

For engineers reviewing the STM6505WCABDG6F datasheet, STM6505WCABDG6F pinout, STM6505WCABDG6F application, or STM6505WCABDG6F equivalent, key selection criteria include dual delayed-reset logic with external capacitor programming (tSRC = 2–15 s), integrated VBAT comparator (1.25 V threshold, 8 mV hysteresis), and simultaneous VCC monitoring + BLD assertion capability.

Technical Context

The STM6505 implements dual combined Smart Reset inputs (SR0/SR1) requiring simultaneous low-level activation for longer than tSRC - programmable via external capacitor on SRC pin - before asserting active-low RST. Its reset output depends on both SR timing validity and VCC voltage crossing factory-set thresholds.

It integrates a dedicated VBAT input with fixed 1.25 V comparator threshold and 8 mV typical hysteresis, driving an independent open-drain BLD output. VCC must be ≥1.575 V for proper VBAT comparator operation, and no internal pull-up exists on BLD.

Key Specifications

Pinout & Package

TDFN8 package: 2 mm × 2 mm × 0.75 mm, 0.5 mm pitch, exposed thermal pad (not electrically connected), RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual Smart Reset with battery monitoring applications.

Compared with MAX6369EUT+T and TPS3808G33DBVR, STM6505WCABDG6F uniquely integrates dual delayed push-button logic, factory-programmable VCC thresholds, and dedicated battery low-detect functionality in a single 2 mm × 2 mm TDFN8 package - enabling compact, self-contained reset and power-health management for space-constrained portable electronics.

Availability

STM6505WCABDG6F is available at Aetrix Electronics and suitable for smartphone power management, e-book system reset control, portable navigation device (PND) cold-start sequencing, and MP3 player battery safety requiring stable component supply and long-term lifecycle support.

Supply support for STM6505WCABDG6F 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 microcontrollers, power management, sensors, and analog ICs for automotive, industrial, and consumer markets.

The STM65xx Smart Reset family targets portable electronics requiring robust, user-interruptible reset behavior and integrated power-supply supervision - designed specifically for mobile phones, e-books, and navigation devices needing dual-button delay logic and battery health awareness.

FAQ

What is the function of the SRC pin on STM6505WCABDG6F?

The SRC pin connects to an external capacitor that sets the Smart Reset setup delay (tSRC) - the minimum time both SR0 and SR1 must remain low before RST is asserted. Typical values range from 0.2 µF (2 s) to 1 µF (10 s), with accuracy dependent on capacitor leakage and PCB layout. The pin draws ~100 nA, requiring low-leakage ceramic or film capacitors placed adjacent to the pin.

How does the VBAT input work, and what external components are required?

VBAT is a high-impedance analog input referenced to a fixed 1.25 V internal comparator. To monitor a battery voltage (e.g., 3.0–4.2 V Li-ion), an external resistor divider scales the battery voltage down to ≤1.25 V at VBAT. For example, a 2:1 divider (e.g., 1 MΩ + 1 MΩ) maps 2.5 V battery to 1.25 V at VBAT. No other passive components are required beyond the divider.

Can RST and BLD outputs be tied together or share a pull-up resistor?

No - RST and BLD are independent open-drain outputs with different assertion conditions (VCC threshold vs. VBAT threshold) and timing behaviors. Sharing a pull-up risks incorrect logic states during partial faults (e.g., BLD active while RST inactive). Each output requires its own pull-up resistor sized per load capacitance and rise-time requirements, typically 10–100 kΩ.

What is the minimum VCC required for the VBAT comparator to operate correctly?

The VBAT comparator requires VCC ≥1.575 V to function - below this, the internal reference and comparator circuitry are not powered. This is explicitly stated in the datasheet: "VCC must be ≥1.575 V for proper operation of the VBAT comparator." At VCC = 1.575 V, the comparator remains functional but BLD assertion timing may vary slightly due to reduced internal bias currents.