Texas Instruments TL7705CP-B

Overview

TL7705CP-B from Texas Instruments is a precision supply-voltage supervisor IC designed as a reset controller for 5-V microprocessor systems. It features a 4.55-V nominal undervoltage detection threshold at the SENSE input, true/complement open-collector RESET outputs, and externally adjustable reset pulse duration via CT pin capacitor timing. It operates across 3.6 V to 18 V supply range and supports industrial temperature range (–40°C to 85°C).

For engineers reviewing the TL7705CP-B datasheet, TL7705CP-B pinout, TL7705CP-B application, or TL7705CP-B equivalent, this page delivers verified functional identity, confirmed 8-pin PDIP package mapping, validated pin roles including RESIN control and REF reference output, exact threshold voltage (4.55 V), hysteresis (30 mV), and real-world reset timing behavior tied to external CT capacitor.

Technical Context

The TL7705CP-B implements a precision bandgap-based voltage reference with temperature compensation to maintain stable 4.55-V threshold over –40°C to 85°C. Its dual-reset architecture provides simultaneous active-high (RESET) and active-low (RESET) signals, both asserted when SENSE falls below V_IT– or RESIN is pulled low.

Reset pulse duration is programmable via external capacitor on CT pin using td ≈ 2.6 × 10⁴ × C_T (seconds), with internal current source charging C_T to ~1.8 V reference. The REF pin supplies a stable 2.53-V reference (±25 mV) for external monitoring or biasing, requiring a 0.1-µF decoupling capacitor.

Key Specifications

Pinout & Package

TL7705CP-B is housed in an 8-pin PDIP (Plastic Dual In-line Package) with 9.81 mm × 6.35 mm body size, through-hole mounting, and industry-standard lead pitch (2.54 mm). RoHS-compliant, NIPDAU lead finish, no MSL restriction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL7705CDR and TPS3808G33DBVR, the TL7705CP-B uniquely combines through-hole PDIP packaging, industrial temperature rating, dual reset outputs, and a buffered reference voltage - making it irreplaceable for legacy 5-V industrial control boards requiring field-serviceability and design flexibility.

Availability

TL7705CP-B is available at Aetrix Electronics and suitable for industrial PLC control, 5-V microcontroller reset, telecom power management, and server board monitoring requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TL7705CP-B 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 ICs.

The TL77xxB family was engineered specifically for robust reset control in microprocessor-based systems, emphasizing precision threshold stability, noise immunity, and flexible output configuration for demanding industrial and telecom applications.

FAQ

What is the exact undervoltage detection threshold voltage for TL7705CP-B?

The TL7705CP-B has a nominal negative-going input threshold voltage (V_IT–) of 4.55 V at 25°C, with guaranteed range of 4.45 V to 4.65 V across its full operating temperature range (–40°C to +85°C). This value is specified in Section 6.5 of the official TI datasheet SLVS037O and applies directly to the TL7705CP-B variant.

Does TL7705CP-B provide both active-high and active-low reset outputs?

Yes, TL7705CP-B provides true (RESET, Pin 6) and complement (RESET, Pin 5) reset outputs. Both are open-collector, enabling independent pull-up/pull-down configurations. This dual-output architecture eliminates the need for external inverters when interfacing with MCUs that accept either reset polarity - a key feature confirmed in the Functional Block Diagram and Pin Functions table of the TL7705CP-B datasheet.

How is reset pulse duration set on TL7705CP-B?

Reset pulse duration on TL7705CP-B is set externally via capacitor C_T connected to Pin 3 (CT). The relationship is td ≈ 2.6 × 10⁴ × C_T, where C_T is in farads and td is in seconds. For example, a 0.1-µF capacitor yields ~2.6 ms delay. This timing mechanism is documented in Section 8.3.2 and Figure 9-1 of the TL7705CP-B datasheet.

What is the purpose of the REF pin on TL7705CP-B?

The REF pin (Pin 1) on TL7705CP-B outputs a precision 2.53-V reference voltage (±25 mV) derived from an internal temperature-compensated bandgap. It is intended for external use - such as biasing comparators or calibrating ADC references - and requires a 0.1-µF capacitor to GND per Section 8.1 and Figure 11-1 of the TL7705CP-B datasheet to ensure stability and noise immunity.

Can TL7705CP-B operate with supply voltages below 5 V?

Yes, TL7705CP-B operates from 3.6 V to 18 V and generates valid reset signals even when V_CC drops to 1 V, as explicitly stated in its "RESET Output Defined From V_CC ≥ 1 V" feature. However, its 4.55-V SENSE threshold means it is optimized for supervising 5-V rails - operation below 4.55 V on the SENSE input triggers reset, regardless of V_CC level above 1 V.