Texas Instruments TL7709AID

Overview

TL7709AID 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 (±0.1 V) negative-going threshold voltage (V_IT−), 20 mV hysteresis, externally adjustable reset pulse duration via CT pin (e.g., 1.3 ms with 0.1 µF), 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 TL7709AID datasheet, TL7709AID pinout, TL7709AID application, or TL7709AID equivalent, key selection considerations include its −40°C to +85°C industrial temperature grade, SOIC-8 package, 3.5–18 V wide supply range, precision 7.6 V sensing threshold, and compatibility with microcontroller reset initialization circuits requiring stable undervoltage detection and programmable delay timing.

Technical Context

The TL7709AID integrates a temperature-compensated bandgap reference (2.53 V typ), a high-precision comparator monitoring the SENSE input against a trimmed 7.6 V threshold, and an RC-based delay timer controlled by the external CT capacitor. Its dual-reset outputs (RESET and RESET) provide simultaneous active-high and active-low signals for flexible interface with diverse logic families.

During power-up, RESET asserts low when V_CC reaches ~3.6 V; if SENSE > V_IT+, the CT timer initiates, and after the programmed delay, both outputs deassert. On undervoltage, both outputs reassert immediately. The REF pin delivers a stable 2.53 V reference usable for external biasing or filtering.

Key Specifications

Pinout & Package

TL7709AID is housed in an 8-pin SOIC (D) package (4.90 mm × 3.91 mm body), 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 supervisor applications.

Compared with TL7709AID, TL7705AID serves lower-voltage systems but shares identical timing and packaging, while TPS3808G33 offers superior accuracy and efficiency at the cost of added external components and loss of dual-output capability-making TL7709AID optimal for fixed 7.6 V industrial reset applications requiring simplicity and signal flexibility.

Availability

TL7709AID is available at Aetrix Electronics and suitable for industrial automation, legacy microcontroller reset, and analog power rail supervision requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TL7709AID 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 leader specializing in analog, embedded processing, and power management technologies, with decades of heritage in high-reliability industrial ICs.

The TL77xxA family was engineered specifically as precision, wide-supply reset supervisors for microcomputer and microprocessor systems-emphasizing robust undervoltage detection, programmable timing, and industrial-grade thermal performance.

FAQ

What is the exact undervoltage detection threshold of the TL7709AID?

The TL7709AID has a guaranteed negative-going input threshold voltage (V_IT−) of 7.6 V ±0.1 V at 25°C, with 20 mV hysteresis. This fixed threshold is factory-trimmed and does not require external resistors, making it ideal for 7.5 V supply monitoring where precision and stability are critical. The TL7709AID maintains this specification across its full −40°C to +85°C operating range.

How do I configure the reset pulse duration for the TL7709AID?

The TL7709AID reset pulse duration is set by an external capacitor connected to the CT pin (Pin 3). Using the formula t_d ≈ 1.3 × 10⁴ × C_T (seconds), a 0.1 µF capacitor yields ~1.3 ms. A 0.22 µF capacitor extends it to ~2.6 ms. Ensure the CT capacitor is ceramic or film type with low leakage; place it close to Pin 3 and GND to minimize noise coupling into the TL7709AID timing circuit.

Does the TL7709AID support both active-high and active-low reset signaling?

Yes, the TL7709AID provides two complementary open-collector outputs: RESET (Pin 6, active-high) and RESET (Pin 5, active-low). Both assert simultaneously during power-up or undervoltage events. Each requires an external pull-up resistor (e.g., 10 kΩ) to V_CC or another logic rail, enabling direct interface with mixed-signal or legacy microcontroller reset inputs.

Can the TL7709AID monitor a supply voltage higher than its own V_CC?

No-the TL7709AID's SENSE input (Pin 7) must be referenced to the same ground as V_CC, and its absolute maximum SENSE voltage is 20 V. However, the device itself operates from V_CC = 3.5–18 V. To monitor higher rails (e.g., 24 V), use an external resistor divider to scale the sensed voltage down to ≤20 V before applying it to SENSE. The TL7709AID's internal comparator compares this scaled voltage against its 7.6 V threshold.

What is the purpose of the REF pin on the TL7709AID?

The REF pin (Pin 1) delivers a stable, temperature-compensated 2.53 V reference voltage with ±5 mV tolerance. It is intended for external use-such as biasing op-amps, setting ADC references, or stabilizing external comparators-and requires a 0.1 µF ceramic capacitor to GND to suppress noise. This reference is derived from the same bandgap core that sets the 7.6 V threshold, ensuring correlated accuracy across the TL7709AID's functions.