Texas Instruments TPS77133DGKRG4

Overview

TPS77133DGKRG4 from Texas Instruments is a 3.3-V fixed-output, 150-mA low-dropout (LDO) regulator with integrated open-drain power-on reset output, housed in an 8-pin MSOP (DGK) package. It delivers ultralow 92-µA quiescent current, 115-mV dropout at full load, ±2% output voltage tolerance, and operates across –40°C to 125°C. It serves as a primary voltage supervisor and reset source in microprocessor-based embedded systems requiring stable, low-noise 3.3-V rail generation.

For engineers reviewing the TPS77133DGKRG4 datasheet, TPS77133DGKRG4 pinout, TPS77133DGKRG4 application, or TPS77133DGKRG4 equivalent, key selection criteria include its 220-ms reset delay, PMOS pass element architecture enabling load-independent quiescent current, compatibility with 1-µF tantalum or 10-µF ceramic output capacitors, and thermal shutdown protection for reliable operation in space-constrained industrial and portable designs.

Technical Context

The TPS77133DGKRG4 employs a PMOS pass transistor architecture that yields both low dropout (115 mV at 150 mA) and quiescent current independent of output load-92 µA from 0 to 150 mA. Its internal voltage reference (1.1834 V) feeds a precision comparator monitoring the regulated output to assert RESET when V_OUT falls below 95% of nominal (3.135 V), with 220-ms delay on power-up.

RESET is an open-drain, active-low output requiring an external pullup resistor; it supports supply voltage supervision in DSP, microcontroller, and FPGA power sequencing. The device achieves 55 µV_rms output noise without bypass capacitors and maintains stability with low-ESR ceramic or tantalum output capacitors down to 1 µF.

Key Specifications

Pinout & Package

TPS77133DGKRG4 is packaged in an 8-pin MSOP (DGK) package - 3.0 mm × 3.0 mm, 0.65 mm pitch, exposed thermal pad (not electrically connected). Pinout follows standard TPS771xx top-view configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS77233DGKR, TPS77133DGKRG4 provides active-low reset timing essential for legacy microcontrollers, while MCP1826-3302E/DB lacks integrated supervision - requiring additional components and PCB area for equivalent system-level reliability.

Availability

TPS77133DGKRG4 is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, automotive body electronics, and network edge gateways requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TPS77133DGKRG4 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 power regulation solutions.

The TPS771xx family was designed specifically for space-constrained, battery-sensitive applications needing integrated reset supervision - targeting microprocessor, DSP, and FPGA power domains where simplicity, low noise, and deterministic startup behavior are critical.

FAQ

What is the function of the RESET pin on the TPS77133DGKRG4?

The RESET pin on the TPS77133DGKRG4 is an open-drain, active-low output that asserts low when the regulated 3.3-V output falls below 95% (3.135 V), and releases (goes high-impedance) after a 220-ms delay once V_OUT rises above that threshold. It requires an external pullup resistor and is used to initiate a clean hardware reset in microcontrollers, DSPs, or FPGAs during power-up or brownout conditions. This function is intrinsic to the TPS77133DGKRG4 and does not require additional circuitry.

Does the TPS77133DGKRG4 require an external bypass capacitor for stable operation?

No, the TPS77133DGKRG4 does not require an external bypass capacitor to achieve stable regulation - it is designed to operate reliably with only a 1-µF tantalum or 10-µF ceramic output capacitor. While a 0.047-µF input bypass capacitor improves transient response when the device is located far from the power source, it is optional. The TPS77133DGKRG4 achieves 55 µV_rms noise without any external filter, distinguishing it from most low-noise LDOs that mandate added capacitance.

What is the minimum input voltage required for the TPS77133DGKRG4 to maintain 3.3-V output at 150 mA?

The minimum input voltage for the TPS77133DGKRG4 to sustain 3.3-V output at 150 mA is calculated as V_OUT + V_DO = 3.3 V + 0.115 V = 3.415 V. Per datasheet specifications, the absolute minimum input is 2.7 V, but for full-load operation, VI must exceed 3.415 V. At lighter loads, dropout decreases proportionally - e.g., at 10 mA, dropout is ~25 mV, allowing operation from ~3.325 V.

How does the enable (EN) pin affect quiescent current in the TPS77133DGKRG4?

When the EN pin of the TPS77133DGKRG4 is pulled high (>2 V), the regulator enters shutdown mode and draws ≤3 µA total supply current at 25°C - a reduction of over 30× versus its 92-µA active-mode quiescent current. This ultra-low standby current enables energy harvesting and battery-backed applications where periodic wake-up is required. The EN pin is TTL-compatible and features hysteresis to prevent chatter near the 0.7 V low-to-high transition threshold.

Can the TPS77133DGKRG4 be used with ceramic output capacitors, and what ESR range is supported?

Yes, the TPS77133DGKRG4 is fully compatible with multilayer ceramic capacitors (MLCCs), including X5R and X7R dielectrics, provided the capacitance is ≥10 µF and the equivalent series resistance (ESR) falls within the stability region defined in Figures 18–21 of the datasheet (typically 0.01–0.1 Ω for 10 µF). For 1-µF tantalum capacitors, ESR must be 0.1–10 Ω. Using out-of-range ESR may cause oscillation or degraded transient response - verified stability data is specific to the TPS77133DGKRG4 and not extrapolated from other LDO families.