Texas Instruments TPS77133DGKR

Overview

TPS77133DGKR from Texas Instruments is a 3.3-V fixed-output, 150-mA low-dropout (LDO) voltage regulator with integrated open-drain power-on reset (RESET) output, 115-mV dropout at 150 mA, 92-µA quiescent current, and 2% output voltage tolerance over line/load/temperature. It serves as a precision supply rail for microcontrollers and DSPs requiring reliable startup supervision.

For engineers reviewing the TPS77133DGKR datasheet, TPS77133DGKR pinout, TPS77133DGKR application, or TPS77133DGKR equivalent, key selection criteria include its 220-ms RESET delay, MSOP-8 (DGK) package footprint, ultralow noise (55 µVrms), thermal shutdown protection, and compatibility with 1-µF tantalum or 10-µF ceramic output capacitors.

Technical Context

The TPS77133DGKR uses a PMOS pass element enabling low dropout (115 mV @ 150 mA) and load-independent quiescent current (92 µA). Its internal comparator monitors regulated output voltage to assert RESET when V_OUT falls below 95% of nominal (3.135 V), with 220-ms delay on power-up.

It features fast transient response optimized for dynamic loads, stable operation with low-ESR capacitors down to 1 µF, and shutdown mode reducing quiescent current to <1 µA via TTL-compatible EN input. The RESET output requires an external pullup resistor and operates as an open-drain signal.

Key Specifications

Pinout & Package

TPS77133DGKR is housed in an 8-pin MSOP (DGK) package - 3.0 mm × 3.0 mm × 1.0 mm body, 0.65 mm pitch, exposed thermal pad (not electrically connected). Pin 1 is marked by a dot or beveled corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS77233DGKR, the TPS77133DGKR provides active-low reset timing critical for microcontroller initialization, while the MCP1700-3302E/TO trades supervision capability for lower quiescent current and smaller footprint - making TPS77133DGKR optimal for integrated-supervision 3.3-V LDO needs.

Availability

TPS77133DGKR is available at Aetrix Electronics and suitable for industrial automation, medical wearables, and battery-powered embedded systems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for TPS77133DGKR 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 analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The TPS771xx family was engineered specifically for space-constrained, battery-sensitive applications needing integrated power-supply supervision - combining LDO regulation with precise reset timing in a thermally efficient MSOP-8 package.

FAQ

What is the minimum input voltage required for TPS77133DGKR to regulate 3.3 V at 150 mA?

The minimum input voltage is calculated as V_OUT + V_DO(max) = 3.3 V + 200 mV = 3.5 V (per datasheet max dropout at 150 mA). However, recommended operating conditions specify VI ≥ 4.3 V for full 150-mA operation at 3.3 V output to ensure margin across temperature and process variation. Below 4.3 V, output current capability decreases linearly with input headroom.

Does TPS77133DGKR require an external pullup resistor on the RESET pin?

Yes, TPS77133DGKR features an open-drain RESET output that requires an external pullup resistor to a valid logic-high voltage (e.g., 3.3 V or 5 V). Typical values range from 10 kΩ to 100 kΩ. Without this resistor, RESET cannot transition to high-impedance state and will remain asserted low, preventing proper system startup sequencing.

Can TPS77133DGKR operate with a 1-µF ceramic output capacitor?

No - while the TPS77133DGKR supports 1-µF tantalum capacitors, it requires ceramic capacitors to be ≥10 µF due to ESR stability constraints shown in Figures 18–21 of the datasheet. A 1-µF ceramic capacitor typically has too low ESR and may cause oscillation; use ≥10 µF X5R/X7R ceramic or ≥1 µF solid tantalum with appropriate ESR range.

What is the RESET timeout delay and threshold voltage for TPS77133DGKR?

The TPS77133DGKR asserts RESET low when V_OUT falls below 95% of 3.3 V (i.e., ≤3.135 V) and releases RESET after a fixed 220-ms delay once V_OUT rises above that threshold during power-up. Hysteresis is 0.5% of nominal output, ensuring noise immunity during marginal voltage conditions.

Is TPS77133DGKR pin-compatible with other devices in the TPS771xx family?

Yes - all TPS771xx variants (e.g., TPS77118DGKR, TPS77150DGKR) share identical 8-pin MSOP (DGK) package, pinout, and terminal functions. Only the fixed output voltage differs; FB/SENSE, RESET, EN, GND, IN, and OUT assignments are consistent across the family, enabling drop-in replacement for different voltage rails.