Texas Instruments TL7705BIDRG4

Overview

TL7705BIDRG4 from Texas Instruments is a precision supply-voltage supervisor IC designed as a reset controller for 5-V microprocessor systems. It monitors the SENSE input for undervoltage conditions, provides true and complement RESET outputs (active-high and active-low), features an externally adjustable reset pulse duration via CT capacitor, and maintains defined RESET behavior down to VCC ≥ 1 V. It operates across –40°C to 85°C and delivers 4.55 V nominal undervoltage threshold with 30 mV hysteresis.

For engineers reviewing the TL7705BIDRG4 datasheet, TL7705BIDRG4 pinout, TL7705BIDRG4 application, or TL7705BIDRG4 equivalent, this page delivers verified electrical specifications, SOIC-8 package mapping, functional pin roles, real-world implementation guidance for microcontroller reset circuits, and validated alternative options for industrial and embedded power-supply monitoring.

Technical Context

The TL7705BIDRG4 implements a precision bandgap-based voltage reference and comparator architecture to detect SENSE input drops below 4.55 V (±50 mV over temperature). Its internal timing circuit uses a current source charging an external CT capacitor to generate a user-defined reset pulse width-td ≈ 26 ms per µF-with ±15% current source tolerance and ±5% reference voltage variation.

Both RESET and RESET outputs are open-collector, requiring external pullup/pulldown resistors; simultaneous termination with matched resistors prevents waveform plateauing. The RESIN pin enables manual reset override, forcing RESET high and RESET low regardless of SENSE status-critical for system-level recovery sequences in factory automation and server platforms.

Key Specifications

Pinout & Package

TL7705BIDRG4 is housed in an SOIC-8 (D) package measuring 4.90 mm × 3.91 mm, RoHS-compliant with NiPdAu lead finish and Moisture Sensitivity Level (MSL) 2 rating (260°C reflow, 1-year floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL7705BIDRG4, TPS3808G33DBVR offers lower power and smaller footprint but sacrifices adjustable timing, dual outputs, and 5-V threshold accuracy-making it unsuitable for legacy 5-V microcontroller reset where TL7705BIDRG4's 4.55-V trip point and 30-mV hysteresis are critical.

Availability

TL7705BIDRG4 is available at Aetrix Electronics and suitable for industrial PLC controllers, 5-V server power management, factory automation HMI panels, and building automation gateways requiring stable component supply across extended temperature ranges.

Supply support for TL7705BIDRG4 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 expertise in high-reliability industrial IC design.

The TL77xxB family was developed specifically for robust, precision supply-voltage supervision in microprocessor and microcontroller systems-emphasizing accurate threshold detection, noise immunity, and flexible reset timing for mission-critical industrial and computing applications.

FAQ

What is the exact undervoltage threshold voltage for TL7705BIDRG4?

The TL7705BIDRG4 has a nominal undervoltage threshold (VIT–) of 4.55 V, with guaranteed range of 4.45 V to 4.65 V over its full operating temperature range of –40°C to +85°C. This value is specified in Section 6.5 of the TI SLVS037O datasheet and applies directly to the TL7705BIDRG4 variant, which shares the TL7705BI temperature grade.

Does TL7705BIDRG4 require external pullup resistors on its RESET outputs?

Yes, TL7705BIDRG4 requires external pullup and pulldown resistors on its open-collector RESET and RESET outputs respectively. TI recommends 10-kΩ resistors for both; using mismatched values may cause waveform plateauing and undefined reset states. This requirement is explicitly stated in Section 9.2.1 and Figure 11-1 of the TL7705BIDRG4 datasheet.

Can TL7705BIDRG4 monitor a 5-V supply directly without external resistive dividers?

Yes, TL7705BIDRG4 is designed to monitor 5-V supplies directly at its SENSE pin. Its 4.55-V threshold aligns precisely with standard 5-V ±5% rails, eliminating need for external dividers. The datasheet Figure 9-1 shows exactly this configuration, confirming direct connection of SENSE to the 5-V microcontroller supply rail.

What is the purpose of the CT pin on TL7705BIDRG4, and how is it configured?

The CT pin on TL7705BIDRG4 sets the reset pulse duration via an external capacitor. With CT = 0.1 µF, the reset remains active for approximately 2.6 ms after the SENSE voltage exceeds the threshold. TI also recommends adding a series resistor (≥560 Ω) between CT and VCC to prevent false triggering during rapid VCC transients, as detailed in Section 10 of the datasheet.

Is TL7705BIDRG4 pin-compatible with other TL77xxB variants like TL7702B or TL7733B?

Yes, TL7705BIDRG4 is pin-compatible with TL7702B and TL7733B in the same SOIC-8 package. All share identical pinout (REF, RESIN, CT, GND, RESET, RESET, SENSE, VCC), enabling drop-in replacement where threshold voltage (2.53 V, 4.55 V, or 3.08 V) matches system requirements-confirmed in the Functional Block Diagram and Pin Configuration sections of the SLVS037O datasheet.