Texas Instruments TPS77733DR

Overview

TPS77733DR from Texas Instruments is a 3.3-V fixed-output, 750-mA low-dropout (LDO) voltage regulator with integrated open-drain power-on reset (RESET) output and 200-ms delay. It features a typical dropout voltage of 260 mV at 750 mA, 85 µA quiescent current, ±2% output voltage tolerance over line/load/temperature, and thermal shutdown protection. It powers microcontroller core logic in battery-backed industrial controllers.

For engineers reviewing the TPS77733DR datasheet, TPS77733DR pinout, TPS77733DR application, or TPS77733DR equivalent, key selection criteria include dropout performance under 750-mA load, RESET timing accuracy, SOIC-8 thermal dissipation limits, and compatibility with 10-µF low-ESR output capacitors.

Technical Context

The TPS77733DR uses a PMOS pass element to achieve low, load-independent quiescent current (85 µA typ) and linearly proportional dropout voltage (260 mV typ at 750 mA). Its internal 1.1834-V reference and error amplifier enable stable regulation with only a 10-µF output capacitor.

RESET functionality monitors regulated output voltage with 92–98% VO trip threshold and 200-ms timeout delay; the open-drain output requires an external pullup resistor and asserts low during undervoltage conditions. Enable (EN) input supports TTL-compatible shutdown, reducing quiescent current to 1 µA.

Key Specifications

Pinout & Package

TPS77733DR is housed in an 8-pin SOIC (D) package with exposed pad not connected internally. Pin 1 is GND; pins 3 and 4 are parallel IN inputs; pins 5 and 6 are parallel OUT outputs; pin 2 is EN (active-high enable); pin 7 is FB/NC (no connect for fixed-output version); pin 8 is open-drain RESET.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS77733DR, TPS76733D offers +250 mA output headroom but adds design complexity for reset generation, while TPS79633DR improves dropout by 100 mV at full load yet eliminates the integrated 200-ms RESET - both require additional circuitry to replicate TPS77733DR's single-chip power-good sequencing capability.

Availability

TPS77733DR is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, automotive body electronics, and test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TPS77733DR 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 specializing in analog, embedded processing, and power management technologies.

The TPS777xx family was designed specifically for battery-powered and thermally constrained applications requiring precise, low-quiescent-current regulation with integrated power-monitoring functions.

FAQ

What is the maximum input voltage rating for the TPS77733DR?

The TPS77733DR has an absolute maximum input voltage rating of 13.5 V. Operation above this level risks permanent device damage. Recommended operating input voltage is 4.3 V to 10 V for optimal dropout and thermal performance at 750 mA load. Exceeding 10 V does not improve regulation but increases power dissipation and junction temperature.

Does the TPS77733DR require an external pullup resistor on the RESET pin?

Yes, the TPS77733DR RESET pin is an open-drain output and requires an external pullup resistor to a valid logic rail (e.g., VI or 3.3 V). Typical values range from 10 kΩ to 100 kΩ. Without the pullup, RESET remains floating and cannot drive downstream reset logic. The datasheet specifies 300 µA sink current capability at valid trip conditions.

Can the TPS77733DR operate without an output capacitor?

No, the TPS77733DR requires a minimum 10-µF output capacitor with ESR between 50 mΩ and 1.5 Ω for stability. Omitting it causes oscillation and regulation failure. Ceramic, tantalum, or aluminum electrolytic types are acceptable if ESR and capacitance meet specifications. Zero-load operation is supported, but capacitor is mandatory.

What is the thermal performance of the TPS77733DR in SOIC-8 package at 750 mA?

In still air (0 CFM), the TPS77733DR in SOIC-8 has a 5.68 mW/°C derating factor and 312 mW max power dissipation at 70°C ambient. At 750 mA with 1-V dropout (VI = 4.3 V), power dissipation is 750 mW × 0.26 V = 195 mW - within safe limits up to ~85°C ambient. Forced airflow improves margin significantly.

Is the TPS77733DR pin-compatible with other members of the TPS777xx family?

Yes, all TPS777xx fixed-output variants (e.g., TPS77715D, TPS77718D, TPS77725D, TPS77733D) share identical SOIC-8 pinout and package dimensions. Output voltage is set internally, so swapping TPS77733DR for TPS77725DR requires only firmware or system-level verification of 2.5-V vs. 3.3-V rail compatibility - no PCB change is needed.