Texas Instruments TPS77818D

Overview

TPS77818D from Texas Instruments is a 750-mA, 1.8-V fixed-output low-dropout (LDO) voltage regulator in an 8-pin SOIC package, featuring an open-drain power-good (PG) output, 260 mV typical dropout at 750 mA, 85 µA typical quiescent current, and ±2% output voltage tolerance over line, load, and temperature. It supports battery-powered embedded systems requiring stable 1.8-V rail generation with precise power sequencing.

For engineers reviewing the TPS77818D datasheet, TPS77818D pinout, TPS77818D application, or TPS77818D equivalent, key selection criteria include PG assertion threshold (92–98% VO), thermal shutdown at 150°C, SOIC-8 thermal derating (5.68 mW/°C), input voltage range (2.7–10 V), and compatibility with 10 µF low-ESR output capacitors.

Technical Context

The TPS77818D uses a PMOS pass element to achieve ultralow, load-independent quiescent current (85 µA typ) and low dropout voltage directly proportional to output current. Its internal 1.1834-V reference and high-impedance feedback amplifier enable stable regulation across −40°C to 125°C junction temperature.

It integrates an open-drain PG output that asserts low when VO drops below 92% of nominal (1.656 V), with 0.5% hysteresis and 1 µA leakage at 5 V. The EN pin accepts TTL-compatible logic (VIH ≥ 1.7 V, VIL ≤ 0.9 V) to enable/disable regulation, reducing standby current to 1 µA.

Key Specifications

Pinout & Package

TPS77818D 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; pin 7 is FB/NC (no connect for fixed-output version); pin 8 is PG (open-drain active-low).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76718D and MCP1826-1802E/DB, the TPS77818D uniquely combines 750 mA output, PG status signaling, ultralow 85 µA quiescent current, and SOIC-8 thermal performance-making it optimal for high-reliability, battery-sensitive 1.8-V systems requiring power sequencing.

Availability

TPS77818D is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, FPGA I/O power, microcontroller core supplies, and battery-powered embedded systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for TPS77818D 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 headquartered in Dallas, Texas, designing and manufacturing analog ICs, embedded processors, and digital signal processors for industrial, automotive, and consumer markets.

The TPS778xx family was developed specifically for high-efficiency, low-noise, power-sequenced LDO regulation in portable and battery-critical systems-emphasizing ultralow quiescent current, precise PG monitoring, and robust thermal protection in standard packages.

FAQ

What is the minimum input voltage required for stable operation of the TPS77818D?

The TPS77818D requires a minimum input voltage of VO + VDO or 2.7 V, whichever is greater. With a nominal 1.8-V output and 260-mV typical dropout, the minimum valid input is 2.06 V at 750 mA load. However, per recommended operating conditions, VI must be ≥2.8 V to guarantee full 1.8-V regulation across temperature and load. Below 2.8 V, output may droop or PG may assert.

How does the PG output of the TPS77818D behave during power-up and fault conditions?

The PG output of the TPS77818D is an open-drain, active-low signal that remains high-impedance until the output reaches 92% of 1.8 V (~1.656 V), then pulls low after a brief stabilization delay. During undervoltage faults-such as input sag or overload-it asserts low again when VO falls below 92% VO and releases only after VO rises above 98% VO (1.764 V), providing 0.5% hysteresis to prevent chatter.

Can the TPS77818D operate without an external pullup resistor on the PG pin?

No-the PG pin of the TPS77818D is open-drain and requires an external pullup resistor to a valid logic rail (e.g., 1.8 V, 3.3 V, or 5 V) to generate a defined high state. Without a pullup, PG floats undefined and cannot drive reset logic or microcontroller interrupts reliably. Typical values range from 10 kΩ to 100 kΩ, selected based on rise time and bus loading requirements.

Is the TPS77818D stable with ceramic output capacitors, and what ESR range is supported?

Yes, the TPS77818D is explicitly designed to be stable with 10 µF ceramic output capacitors. The datasheet specifies an ESR range of 50 mΩ to 1.5 Ω for guaranteed stability. Multilayer ceramic capacitors (MLCCs) meeting this ESR window-such as X5R/X7R 10 µF 0805 or 1206 devices-are fully compatible and eliminate the need for bulkier tantalum or aluminum electrolytics.

Does the TPS77818D require a minimum load current to maintain regulation?

No-the TPS77818D has no minimum load requirement. It remains stable and maintains regulation from zero load up to 750 mA, as confirmed in the application information section. This eliminates the need for dummy loads in low-power or sleep-mode applications, directly supporting energy-efficient design goals.