Texas Instruments TL7709ACDR

Overview

TL7709ACDR from Texas Instruments is a precision supply-voltage supervisor IC designed for reset control in microprocessor systems operating at 7.6 V nominal supply. It features a fixed 7.6 V threshold (VIT+), 20 mV hysteresis, externally adjustable reset pulse duration via CT capacitor, temperature-compensated 2.53 V reference output, and dual active-high/active-low open-collector RESET outputs. It is used in TMS1XXXNLL-based embedded controllers requiring reliable power-on and brownout reset.

For engineers reviewing the TL7709ACDR datasheet, TL7709ACDR pinout, TL7709ACDR application, or TL7709ACDR equivalent, key selection considerations include its 7.6 V undervoltage detection threshold, SOIC-8 package compatibility, −40°C to +85°C industrial temperature grade (note: TL7709ACDR is C-grade, 0°C to 70°C), CT-timed reset delay, and dual complementary reset outputs for legacy microcontroller interface.

Technical Context

The TL7709ACDR implements a precision voltage-sense comparator with internal trimmed reference, monitoring SENSE input against a 7.6 V trip point (VIT+) with 20 mV hysteresis to prevent chatter during threshold crossing. Its internal delay timer is controlled by an external capacitor (CT) connected to Pin 3, enabling programmable reset pulse widths from ~0.65 ms to 2.6 ms depending on capacitance value.

It provides two independent reset outputs: RESET (active-low, open-collector) and RESET (active-high, open-collector), both asserted low/high respectively during undervoltage events. The REF pin delivers a stable 2.53 V ±5 mV reference usable for external circuitry, and the device operates across a 3.5 V to 18 V supply range while consuming only 1.8–3 mA quiescent current.

Key Specifications

Pinout & Package

TL7709ACDR is housed in an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, RoHS-compliant with NiPdAu lead finish and Level-1 moisture sensitivity rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supply-voltage supervision applications.

Compared with TL7709ACP, TL7709ACDR offers surface-mount compatibility and tape-and-reel packaging for automated assembly, while TPS3808G33 trades fixed-threshold simplicity and dual outputs for configurability and nanoamp quiescent current - making it unsuitable as a direct functional replacement in TMS1XXXNLL designs.

Availability

TL7709ACDR is available at Aetrix Electronics and suitable for industrial control systems, legacy microcontroller platforms, and embedded instrumentation requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for TL7709ACDR 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The TL77xxA family was engineered specifically as cost-effective, precision supply-voltage supervisors for microcomputer and microprocessor reset control - emphasizing robustness, wide supply tolerance, and minimal external component count in industrial environments.

FAQ

What is the exact undervoltage detection threshold of the TL7709ACDR?

The TL7709ACDR has a precisely trimmed positive-going input threshold voltage (VIT+) of 7.6 V typical, with a guaranteed range of 7.5 V to 7.7 V at 25°C. This fixed threshold eliminates the need for external resistor dividers and ensures consistent reset behavior across temperature and unit-to-unit variation in TMS1XXXNLL-based systems.

Does the TL7709ACDR require an external timing capacitor, and what value is recommended?

Yes, the TL7709ACDR requires an external capacitor (CT) connected to Pin 3 to set the reset pulse duration. A 0.1 µF capacitor yields a typical delay of 1.3 ms, aligning with common microcontroller reset hold-time requirements. The relationship is td ≈ 1.3×10⁴ × CT (in seconds), allowing fine-tuning from 0.65 ms to 2.6 ms across the recommended 0.05–0.2 µF range.

Can the TL7709ACDR's REF pin be used as a system reference for other circuitry?

Yes, the REF pin on the TL7709ACDR delivers a stable 2.53 V ±5 mV reference at 25°C, with total drift under ±16 mV from −40°C to +85°C. It is intended for use as an auxiliary reference in analog signal chains or ADC biasing, provided a 0.1 µF bypass capacitor is placed directly between REF and GND to suppress noise coupling.

What is the operating temperature range specified for the TL7709ACDR?

The TL7709ACDR is rated for commercial temperature operation from 0°C to +70°C ('C' suffix). It is not rated for extended industrial temperatures (−40°C to +85°C); for that range, the TL7709AIDR variant must be selected. This distinction is critical for thermal design validation in enclosed or high-ambient environments.

How do the RESET and RESET outputs differ in functionality on the TL7709ACDR?

The TL7709ACDR provides two complementary open-collector outputs: RESET (Pin 6) is active-low and commonly used to drive standard microcontroller reset inputs, while RESET (Pin 5) is active-high and supports systems requiring high-asserted reset signals. Both outputs are asserted simultaneously during undervoltage events and de-assert after the CT-determined delay, enabling flexible interface design without external inverters.