Texas Instruments TL7705ACDE4

Overview

TL7705ACDE4 from Texas Instruments is a precision supply-voltage supervisor IC designed as a reset controller for 5-V microcomputer systems. It features a 4.55 V ±0.05 V threshold voltage (V_IT−), 15 mV hysteresis, externally adjustable reset pulse duration via CT pin, temperature-compensated 2.53 V reference output, and operates across 3.5 V to 18 V supply range. It delivers active-low and active-high complementary reset signals for reliable system initialization in TTL-compatible applications.

For engineers reviewing the TL7705ACDE4 datasheet, TL7705ACDE4 pinout, TL7705ACDE4 application, or TL7705ACDE4 equivalent, key selection criteria include undervoltage detection accuracy at 5 V rails, open-collector output drive capability (±16 mA), timing capacitor-based delay configurability, thermal stability over 0°C to 70°C, and SOIC-8 package compatibility with legacy board layouts.

Technical Context

The TL7705ACDE4 implements a precision comparator with trimmed internal voltage reference to monitor SENSE input against a fixed 4.55 V negative-going threshold. Its delay timer uses an external capacitor (CT) connected to Pin 3, generating a reset pulse duration governed by t_d = 1.3 × 10⁴ × C_T (seconds). The device asserts RESET (low) and RESET (high) simultaneously during undervoltage events and releases them after the programmable delay when SENSE exceeds V_IT+.

It integrates a stable 2.53 V reference output (REF, Pin 1) usable for external biasing or calibration, and supports both direct VCC monitoring and resistor-divider SENSE configurations. All outputs are open-collector, requiring external pull-up resistors, and the IC remains functional down to 3.5 V supply while surviving up to 20 V absolute maximum rating.

Key Specifications

Pinout & Package

TL7705ACDE4 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 TPS3808G01QDBVRQ1 and MAX692CPA+, TL7705ACDE4 provides unique value in applications requiring field-adjustable reset timing, a precision 2.53 V reference for auxiliary circuits, and dual active-reset signaling-all in a cost-optimized SOIC-8 footprint compatible with high-volume consumer manufacturing.

Availability

TL7705ACDE4 is available at Aetrix Electronics and suitable for computer motherboards, industrial microcontroller units, embedded audio systems, and TTL-level peripheral enable sequencing requiring stable component supply and long-term production continuity.

Supply support for TL7705ACDE4 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 consumer markets since 1930.

The TL77xxA family was engineered specifically as cost-effective, precision reset controllers for microcomputer and microprocessor systems-emphasizing reliability, threshold accuracy, and ease of integration in 5-V and multi-rail digital platforms.

FAQ

What is the exact undervoltage detection threshold of TL7705ACDE4?

The TL7705ACDE4 has a guaranteed negative-going input threshold voltage (V_IT−) of 4.55 V ±0.05 V at 25°C, optimized for reliable reset assertion in 5-V TTL and microcomputer systems. This value is laser-trimmed during manufacturing and exhibits minimal drift over temperature (±5 mV from 0°C to 70°C), ensuring consistent behavior across operating conditions without external calibration.

How do I configure the reset pulse duration for TL7705ACDE4?

Reset pulse duration for TL7705ACDE4 is set by connecting an external capacitor (CT) between Pin 3 (CT) and GND. The relationship is t_d = 1.3 × 10⁴ × C_T, where C_T is in farads and t_d in seconds. For example, a 0.1 µF capacitor yields ~1.3 ms delay. TI recommends using a ceramic capacitor with low ESR and routing the CT trace away from noisy signals to prevent premature release.

Does TL7705ACDE4 provide both active-high and active-low reset outputs?

Yes, TL7705ACDE4 provides two complementary reset outputs: RESET (Pin 6, active-low open-collector) and RESET (Pin 5, active-high open-collector). Both assert simultaneously during undervoltage events and deassert together after the CT-timed delay. Each output supports ±16 mA drive strength and requires external pull-up resistors-enabling direct interfacing with diverse logic families without level-shifting.

Can TL7705ACDE4 monitor voltages other than 5 V?

Yes-while TL7705ACDE4's internal threshold is fixed at 4.55 V, its SENSE input (Pin 7) accepts 0–10 V, allowing use with resistor dividers to supervise higher rails (e.g., 12 V or 15 V) or lower rails via scaling. For instance, a 2:1 divider on a 9-V supply presents 4.5 V to SENSE, triggering reset near 9 V collapse. The device's wide 3.5–18 V VCC range supports such configurations without auxiliary regulators.

What is the purpose of the REF pin on TL7705ACDE4?

The REF pin (Pin 1) delivers a precision 2.53 V ±5 mV temperature-compensated voltage reference, usable for external analog functions such as ADC reference, sensor biasing, or comparator thresholds. It requires a 0.1 µF ceramic capacitor to GND for stability and noise rejection. Unlike dedicated reference ICs, REF is derived from the same bandgap core as the threshold comparator-ensuring correlated drift and high matching accuracy in supervisory applications.