Texas Instruments TLC7705QD

Overview

TLC7705QD from Texas Instruments is a micropower supply voltage supervisor IC with fixed 4.55 V sense threshold, active-low RESET output, programmable delay via external capacitor, and operation across –40°C to 125°C. It provides power-on reset generation, undervoltage supervision, and power-down control for static RAM with battery backup in microprocessor systems.

For engineers reviewing the TLC7705QD datasheet, TLC7705QD pinout, TLC7705QD application, or TLC7705QD equivalent, this page delivers verified electrical specs, SOIC-8 package details, timing behavior (td = 2.1×10⁴ × CT), reset assertion at VDD ≥1 V, and design guidance for medical imaging and industrial control systems requiring high-temperature reliability.

Technical Context

The TLC7705QD implements a precision voltage sensor with temperature-compensated reference and hysteresis (70 mV) to prevent oscillation during threshold crossing. Its internal timer ensures stable reset assertion after undervoltage events, with delay time fully determined by an external capacitor connected to the CT pin.

It supports dual-mode reset control: when CONTROL is grounded, RESET becomes active-high; otherwise, it operates as active-low. The device monitors SENSE voltage continuously after VDD reaches ≥2 V and asserts RESET until SENSE exceeds 4.55 V and the delay timeout expires.

Key Specifications

Pinout & Package

Package: SOIC-8 (D package), 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant NIPDAU lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC7705ID and TPS3808G33, the TLC7705QD uniquely combines high-temperature qualification (–40°C to 125°C), 4.55 V threshold matching standard 5 V rails, programmable delay, and integrated SRAM power-down logic-making it the only option supporting medical imaging and automotive ADAS applications requiring all four features simultaneously.

Availability

TLC7705QD is available at Aetrix Electronics and suitable for medical imaging systems, industrial motor drives, and automotive ADAS modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TLC7705QD 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 delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TLC77xx family was designed specifically for robust, low-power supply monitoring in microcomputer systems-emphasizing precision threshold stability, programmable timing, and SRAM retention support in harsh environments.

FAQ

What is the exact sense threshold voltage of the TLC7705QD?

The TLC7705QD has a guaranteed negative-going input threshold voltage (VIT–) of 4.47 V (minimum) to 4.63 V (maximum) across its full operating temperature range of –40°C to 125°C, with a typical value of 4.55 V at 25°C. This threshold is internally fixed and does not require external resistors, making the TLC7705QD ideal for monitoring standard 5 V power rails.

How does the TLC7705QD generate its reset delay time?

The TLC7705QD generates reset delay time (td) using an external capacitor connected to the CT pin, following the formula td = 2.1 × 10⁴ × CT. For example, a 100 nF capacitor yields approximately 2.1 ms delay. This capacitor-based timing eliminates trimming components and provides predictable, temperature-stable hold times without software intervention-critical for reliable hardware-initiated resets in the TLC7705QD.

Can the TLC7705QD be used to control battery-backed static RAM during power failure?

Yes, the TLC7705QD supports power-down control for static RAM with battery backup. By connecting the CONTROL pin to the microprocessor's memory bank select signal and driving the RAM's chip select (CS) with the RESET output, the TLC7705QD automatically disables the memory during main power loss. This function is explicitly documented in the TLC7705QD datasheet Figure 10 and requires the TLC7705QD's power to be supplied by the backup battery.

What is the minimum supply voltage at which the TLC7705QD asserts RESET?

The TLC7705QD asserts RESET when VDD reaches 1 V, ensuring a defined reset state even during slow power ramp-up or brown-out conditions. This specification-called the power-up reset voltage (Vres)-is guaranteed across the full operating temperature range and enables reliable initialization of downstream logic before the 2 V minimum recommended operating voltage is reached, a key capability of the TLC7705QD.

Does the TLC7705QD have both active-high and active-low reset outputs?

Yes, the TLC7705QD provides two complementary reset outputs: RESET (active-low) and RESET (active-high). These outputs are synchronized and eliminate the need for external inverters in systems requiring either polarity. The RESET output is open-drain compatible and requires an external pull-up resistor, while RESET is a push-pull output capable of directly driving logic inputs-a dual-output architecture confirmed in the TLC7705QD functional block diagram and timing diagrams.