STMicroelectronics TL7705ACD1013TRA

Overview

TL7705ACD1013TRA from STMicroelectronics is a precision supply voltage supervisor IC designed for microprocessor reset control, featuring a 4.5 V ±2.5% threshold voltage, true/complement RESET outputs, externally adjustable reset pulse width (0.65–2.6 ms with 0.1 µF CT), and operation across 3.6–18 V supply range. It delivers automatic power-on and brownout reset in embedded controllers requiring reliable startup sequencing.

For engineers reviewing the TL7705ACD1013TRA datasheet, TL7705ACD1013TRA pinout, TL7705ACD1013TRA application, or TL7705ACD1013TRA equivalent, key selection factors include its fixed 4.5 V sensing threshold, SO-8 package compatibility, dual active-high/active-low reset outputs, and temperature-compensated reference enabling stable operation from 0°C to 70°C.

Technical Context

The TL7705ACD1013TRA integrates a precision bandgap voltage reference (2.53 V typ.) and comparator with hysteresis (15 mV typ.) to detect supply drops below 4.5 V. Its internal timing circuit uses an external capacitor on CT (Pin 3) to generate programmable reset pulse widths via t_po = 1.3×10⁴ × C_T.

It provides complementary TTL-compatible outputs: RESET (active-high) and RESET (active-low), both capable of sourcing/sinking ≥16 mA. The SENSE input accepts up to 10 V, and REF (Pin 1) requires a 0.1 µF bypass capacitor to suppress transients.

Key Specifications

Pinout & Package

TL7705ACD1013TRA is housed in an SO-8 (Small Outline, 8-pin) surface-mount package with standard 1.27 mm pitch, JEDEC MS-012AC compliant footprint, and thermal resistance R_{th j-amb} = 120°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and MAX809TRD2T, TL7705ACD1013TRA uniquely supports wide-supply (3.6–18 V), fixed 4.5 V threshold, dual complementary outputs, and capacitor-adjustable reset duration-making it optimal for 5 V/12 V microcontroller systems needing robust brownout recovery.

Availability

TL7705ACD1013TRA is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical infusion pumps, and point-of-sale terminals requiring stable component supply across extended temperature and voltage ranges.

Supply support for TL7705ACD1013TRA 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The TL7700A series belongs to ST's power management supervisor product line, engineered specifically for deterministic microprocessor reset generation in systems subject to variable or noisy supply conditions.

FAQ

What is the function of the REF pin (Pin 1) on TL7705ACD1013TRA?

The REF pin outputs a precision 2.53 V temperature-compensated bandgap reference voltage used internally to set the 4.5 V SENSE threshold. A 0.1 µF capacitor must be connected from REF to GND to stabilize the reference and reject fast supply transients that could cause false resets.

Can TL7705ACD1013TRA monitor a 12 V supply directly?

Yes. The SENSE input (Pin 6) is rated for up to 10 V, but the device is intended for monitoring regulated rails like 5 V. To supervise a 12 V supply, use a resistive divider (e.g., 7.8 kΩ + 10 kΩ as specified for TL7705A) to scale the voltage down to ≤10 V at SENSE while preserving the 4.5 V threshold ratio.

How is the reset pulse width adjusted on TL7705ACD1013TRA?

Reset pulse width is set by an external capacitor connected between CT (Pin 3) and GND. Using the formula t_po = 1.3 × 10⁴ × C_T, a 0.1 µF capacitor yields a typical 1.3 ms pulse. Values from 0.05 µF to 0.2 µF produce pulses ranging from ~0.65 ms to ~2.6 ms.

Does TL7705ACD1013TRA provide both active-high and active-low reset signals?

Yes. It provides true and complement outputs: RESET (Pin 4) is active-low open-collector, and RESET (Pin 8) is active-high push-pull. This eliminates the need for external inverters when interfacing with MCUs requiring either polarity, improving signal integrity and simplifying layout.