Texas Instruments TLC7705QDR

Overview

TLC7705QDR 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 over –40°C to 125°C. It provides power-on reset, undervoltage supervision, and power-down control for static RAM with battery backup in microprocessor systems.

For engineers reviewing the TLC7705QDR datasheet, TLC7705QDR pinout, TLC7705QDR application, or TLC7705QDR equivalent, key selection criteria include its 4.55 V precision threshold, 16 µA max supply current, SOIC-8 (D) package, –40°C to 125°C extended temperature rating, and compatibility with battery-backed memory retention circuits.

Technical Context

The TLC7705QDR monitors the SENSE input against an internal temperature-compensated 4.55 V reference and asserts RESET when voltage drops below threshold plus hysteresis (70 mV). Its internal timer generates a user-defined delay (td = 2.1 × 10⁴ × CT) before deasserting RESET after recovery.

It supports dual-mode operation: when CONTROL is grounded, RESET becomes active-high; when CONTROL is high, it enables power-down logic for static RAM chip select control during brownout. The device guarantees defined RESET output down to VDD ≥ 1 V and operates across 2 V to 6 V supply range.

Key Specifications

Pinout & Package

The TLC7705QDR is housed in an 8-pin SOIC (D) package, 3.91 mm × 4.9 mm, RoHS-compliant, with NIPDAU lead finish and moisture sensitivity level (MSL) 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV803EB29DBVR and TPS3808G33DBVR, the TLC7705QDR uniquely combines 4.55 V threshold, capacitor-programmable delay, and dedicated CONTROL logic for battery-backed SRAM - making it irreplaceable in 5 V industrial systems requiring deterministic power-down sequencing.

Availability

TLC7705QDR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical imaging sequencers, and energy meter backup memory systems requiring stable component supply across extended temperature ranges.

Supply support for TLC7705QDR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and industrial-grade qualification.

The TLC77xx family was designed specifically for robust power-supply monitoring in microcomputer and microprocessor systems, emphasizing micropower consumption, wide temperature operation, and integrated power-down control for battery-backed memory.

FAQ

What is the exact sense threshold voltage of the TLC7705QDR?

The TLC7705QDR has a nominal sense threshold voltage of 4.55 V, with guaranteed minimum and maximum values of 4.47 V and 4.63 V respectively, measured across the full operating temperature range of –40°C to 125°C. This fixed threshold is internally trimmed and temperature-compensated, eliminating need for external resistive dividers. The device uses this threshold to assert RESET when the SENSE input falls below it.

How does the CONTROL pin affect the behavior of the TLC7705QDR?

The CONTROL pin on the TLC7705QDR determines reset polarity and enables power-down functionality: when CONTROL is tied to GND, RESET becomes active-high; when CONTROL is high, the device activates internal logic to support static RAM chip select control during power failure. This allows the TLC7705QDR to automatically disable memory access and preserve data using battery backup - a feature not found in standard supervisors.

Can the TLC7705QDR operate reliably at 1.8 V supply voltage?

No, the TLC7705QDR requires a minimum supply voltage of 2 V per its recommended operating conditions. While RESET output is defined down to VDD ≥ 1 V for early fault detection, functional supervision - including accurate threshold comparison and delay timing - is only guaranteed within the 2 V to 6 V range. Operating below 2 V may result in undefined behavior or failure to assert RESET correctly.

What external capacitor value yields a 100 ms delay time for the TLC7705QDR?

Using the formula td = 2.1 × 10⁴ × CT, a 100 ms (0.1 s) delay requires CT = 0.1 / 21000 ≈ 4.76 nF. A standard 4.7 nF ceramic capacitor is appropriate for this timing. The TLC7705QDR's delay accuracy depends on capacitor tolerance and temperature coefficient; X7R or C0G dielectrics are recommended for stability across –40°C to 125°C.

Is the TLC7705QDR pin-compatible with other devices in the TLC77xx family?

Yes, all TLC77xx devices in the SOIC-8 (D) package - including TLC7701QDR, TLC7725QDR, TLC7703QDR, TLC7733QDR, and TLC7705QDR - share identical pinout and footprint. This allows direct substitution based on threshold voltage requirement (1.1 V, 2.25 V, 2.63 V, 2.93 V, or 4.55 V) without PCB redesign, provided the application's voltage monitoring point matches the selected threshold.