STMicroelectronics TL7705AID1013TRA

Overview

TL7705AID1013TRA from STMicroelectronics is a precision supply voltage supervisor IC designed for power-on and brown-out reset generation in microprocessor systems. It features a 4.5 V ±50 mV threshold voltage, true/complement RESET outputs, external capacitor-adjustable reset pulse width (tpo = 1.3×10⁴ × CT), and operates across 3.6–18 V supply range with –25°C to 85°C temperature rating.

For engineers reviewing the TL7705AID1013TRA datasheet, TL7705AID1013TRA pinout, TL7705AID1013TRA application, or TL7705AID1013TRA equivalent, this device delivers deterministic reset timing via external CT capacitor, stable reference voltage (2.53 V typ), hysteresis-controlled sensing, and dual active-high/active-low reset signals for robust system initialization in embedded controllers and industrial MCUs.

Technical Context

The TL7705AID1013TRA implements a precision bandgap-based voltage reference with temperature compensation, enabling accurate 4.5 V threshold detection at the SENSE input. Its internal comparator monitors supply voltage against this reference and triggers reset assertion when VS drops below VT or during power-up until VS exceeds VT + hysteresis (15 mV).

Reset pulse width is fully programmable via external capacitor on CT (Pin 3), yielding tpo = 1.3×10⁴ × CT seconds; typical 0.1 µF yields 1.3 ms. REF output (Pin 1) supplies a buffered 2.53 V reference requiring 0.1 µF bypassing to suppress transients and ensure stable sensing.

Key Specifications

Pinout & Package

TL7705AID1013TRA is housed in an 8-pin SOIC (SO8) package with standard 1.27 mm pitch, JEDEC MS-012AC compliant, and rated for surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3823-45DBVR and MAX6326–45D3+, TL7705AID1013TRA uniquely offers both true/complement reset outputs and externally adjustable pulse width - critical for legacy MCU designs requiring precise timing control and dual-signaling without added components.

Availability

TL7705AID1013TRA is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical infusion pump MCUs, and energy meter microcontrollers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TL7705AID1013TRA 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

TL7705AID1013TRA belongs to the TL7700A series of precision voltage supervisors, engineered specifically for deterministic power-on and brown-out reset generation in microprocessor-based systems where reliability under voltage transients is critical.

FAQ

What is the function of the REF pin (Pin 1) on TL7705AID1013TRA?

The REF pin outputs a buffered, temperature-compensated 2.53 V reference voltage derived from the internal bandgap. It is intended for use as a precision bias source for external analog circuits-such as ADC references or sensor conditioning-requiring stability across –25°C to +85°C. A mandatory 0.1 µF capacitor must be placed between REF and GND to suppress high-frequency noise and ensure sensing accuracy.

How is the reset pulse width determined, and what capacitor value yields a 2.6 ms timeout?

The reset pulse width (tpo) is calculated as tpo = 1.3 × 10⁴ × CT seconds, where CT is the capacitor value in farads connected between Pin 3 (CT) and GND. To achieve 2.6 ms (0.0026 s), solve 0.0026 = 1.3 × 10⁴ × CT → CT = 200 nF. A 220 nF capacitor is commonly used for margin, delivering ~2.86 ms, verified per datasheet switching characteristics table.

Can TL7705AID1013TRA monitor a 3.3 V supply directly?

No-TL7705AID1013TRA's SENSE input has a fixed 4.5 V threshold and maximum rating of 10 V, making it unsuitable for direct 3.3 V monitoring. For 3.3 V systems, use TL7703A (3.3 V threshold) or implement a resistive divider to scale 3.3 V to ≥4.5 V at SENSE-but note that divider impedance affects accuracy and hysteresis performance per datasheet note 3.

What is the purpose of the RESIN pin, and how should it be used in system design?

RESIN (Pin 8) is an active-low manual reset input that forces immediate reset assertion regardless of supply voltage level. It is typically connected to a front-panel pushbutton (via pull-up resistor) or a watchdog timer output. When pulled low, it overrides normal voltage monitoring and holds both RESET outputs active until RESIN returns high, enabling field service recovery or fail-safe intervention without power cycling.