Texas Instruments TL7733BIDR

Overview

TL7733BIDR from Texas Instruments is a precision supply-voltage supervisor IC designed as a reset controller for microprocessor and microcontroller systems. It monitors the SENSE input for undervoltage conditions, provides true and complement reset outputs (RESET and RESET), features a 3.08 V nominal threshold with 10 mV hysteresis, and supports adjustable reset pulse duration via external CT capacitor. It operates across –40°C to 85°C and delivers stable reset assertion down to VCC ≥ 1 V - critical for reliable power-up sequencing in industrial embedded controllers.

For engineers reviewing the TL7733BIDR datasheet, TL7733BIDR pinout, TL7733BIDR application, or TL7733BIDR equivalent, this page delivers verified specifications, validated pin functions, confirmed thermal and timing behavior, and real-world implementation guidance - all specific to the TL7733BIDR SOIC-8 variant with industrial temperature range and NIPDAU lead finish.

Technical Context

The TL7733BIDR implements a precision voltage-sensing architecture using a temperature-compensated bandgap reference and comparator with hysteresis. Its SENSE input detects supply drops below 3.03–3.16 V (full-range), while the CT pin interfaces with an internal current source (≈38 nA ±15%) to generate user-defined reset delays via external capacitor timing (td ≈ 2.6×10⁴ × CT).

It delivers dual open-collector reset outputs - active-high RESET and active-low RESET - both defined from VCC ≥ 1 V, with output drive capability of ±20 mA at VOH = VCC – 1.5 V and VOL = 0.4 V. The REF pin supplies a stable 2.48–2.58 V reference for external circuitry or noise filtering.

Key Specifications

Pinout & Package

TL7733BIDR is housed in an SOIC-8 package (4.90 mm × 3.91 mm body size) with standard JEDEC MS-012AC footprint and NIPDAU lead finish. Pin 1 is marked by a beveled corner or dot; device orientation follows TI's top-view convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and MAX6326LT33D3+T, the TL7733BIDR uniquely combines adjustable reset timing, dual complementary outputs, and a buffered 2.5 V reference - making it the only option among the three capable of supporting complex reset coordination and external analog circuit stabilization in industrial microcontroller systems.

Availability

TL7733BIDR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, factory automation controllers, and building management systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TL7733BIDR 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 operating under noisy, wide-voltage, and thermally demanding conditions - targeting industrial automation, infrastructure, and embedded computing.

FAQ

What is the exact reset threshold voltage of TL7733BIDR over temperature?

The TL7733BIDR has a nominal negative-going input threshold (V_IT–) of 3.08 V at 25°C, specified from 3.03 V to 3.16 V across the full –40°C to 85°C operating range. This 3.3 V-compatible threshold ensures reliable detection of brownout events on standard 3.3 V rails while maintaining margin against noise-induced false triggering.

Does TL7733BIDR require external pullup/pulldown resistors on its reset outputs?

Yes, TL7733BIDR requires external resistors: a pullup resistor (typically 10 kΩ) on RESET and a pulldown resistor (also typically 10 kΩ) on RESET. Both outputs are open-collector and must be terminated to define logic states - even if only one output is used - to prevent waveform plateauing that could cause undefined reset behavior in the target microcontroller.

How is the reset pulse duration set for TL7733BIDR, and what is the formula?

The reset pulse duration for TL7733BIDR is set by an external capacitor connected to the CT pin. 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 approximately 2.6 ms. TI recommends 0.1 µF for general-purpose use, and notes that timing accuracy varies ±15% due to internal current-source tolerance.

Can TL7733BIDR monitor a 5 V supply directly, or is it limited to 3.3 V rails?

TL7733BIDR can monitor any supply within its 3.6–18 V V_CC range, but its SENSE input threshold is fixed at ~3.08 V. To supervise a 5 V rail, use a resistor divider to scale the 5 V signal down to ~3.08 V at SENSE. The device itself does not support adjustable thresholds - only the TL7705B (4.55 V) and TL7702B (2.53 V) variants offer different fixed thresholds in the same family.

What is the purpose of the REF pin on TL7733BIDR, and how should it be used?

The REF pin on TL7733BIDR provides a buffered 2.48–2.58 V reference voltage, derived from an internal temperature-compensated bandgap. It must be bypassed with a 0.1 µF capacitor to GND to suppress noise and prevent false triggering. REF can also serve as a stable reference for external ADCs, comparators, or bias networks in the same system - enhancing overall analog signal integrity.