Texas Instruments TPS77901DGKRG4

Product Summary TPS77901DGKRG4 Linear Regulator Family

The TPS77901DGKRG4 series from Texas Instruments is a low-dropout (LDO) linear regulator family offering robust performance and flexibility for modern electronic designs. These regulators deliver up to 250 mA of output current, come in a compact 8-pin MSOP (DGK) package, and feature integrated power-on reset functionality. This series includes fixed output versions at 1.8 V, 2.5 V, and 3 V, as well as a fully adjustable output option, supporting a wide range of application needs in consumer electronics, industrial systems, and battery-powered devices.

Main Attributes of the TPS77901DGKRG4 Family

Engineers will value the TPS77901DGKRG4’s technical features that support both high reliability and efficiency:

250-mA continuous output current capability

Very low dropout voltage, typically 200 mV at full load (250 mA, TPS77930)

Ultra-low quiescent current (92 μA typical, dropping to <1 μA in shutdown mode)

Fast transient response for dynamic load conditions

Integrated power-on reset output with 220 ms delay, facilitating system supervision

Available in fixed (1.8 V, 2.5 V, 3 V) and adjustable output versions (1.5 V to 5.5 V)

Low output noise (55 μVrms in TPS77918, even without a bypass capacitor)

2% output voltage tolerance across line, load, and temperature for fixed versions

Compatible with low ESR ceramic (≥10 μF) and tantalum (≥1 μF) output capacitors

These features ensure stable operation in variable environments, support stringent noise requirements, and maximize battery life in portable applications.

Electrical and Thermal Characteristics of the TPS77901DGKRG4 Family

The TPS77901DGKRG4 operates over a junction temperature range of -40°C to +125°C, ensuring reliability for demanding industrial and automotive environments. Absolute maximum ratings include an input voltage up to 13.5 V and output voltages up to 5.5 V. Peak output current is internally limited to prevent catastrophic failure.

For routine operation, minimum input voltage is determined by the sum of output voltage plus maximum dropout; maximum input is capped at 10 V for optimal reliability. Power dissipation and junction temperature should be managed within the specified limits: the maximum allowable dissipation is calculated based on ambient temperature, junction-to-ambient thermal resistance (266.2°C/W for MSOP-8), and the load profile. Exceeding these parameters will trigger internal thermal shutdown protection, and device operation resumes only when temperature drops below recovery threshold.

Pin Descriptions and Interface Details for TPS77901DGKRG4 Family

The TPS77901DGKRG4 includes several critical pins uniquely suited for precise power management:

EN (Enable): Activates the regulator with a logic high; logic low puts the device in ultra-low-power shutdown.

SENSE (for fixed-output options): Should be directly tied to the output terminal with minimal trace length, as noise pickup can degrade regulation accuracy. RC filtering is discouraged due to risk of oscillation.

FB (Feedback, for adjustable-output versions): Connects to an external resistor divider to set the output voltage, also requiring short, direct routing.

RESET: An open-drain, active-low output signaling regulated status. It transitions to high impedance after the output reaches 95% of nominal for 220 ms, or drops to low impedance if the output voltage falls below 95% due to load or fault. A pull-up resistor is needed for proper function.

Correct pin usage is essential for stable operation and successful integration into system-level design.

Standard Performance Metrics for the TPS77901DGKRG4 Family

Key performance metrics observed across the TPS77901DGKRG4 family include:

Output voltage stability across temperature and load

Fast response to load transients and enable/disable signaling at startup

Region of stability defined by output capacitor ESR vs. output current, critical for selecting appropriate capacitors

Typical dropout voltage versus junction temperature graphs

Noise characteristics under real-world loading

These metrics are crucial for engineers performing design validation, especially for noise-sensitive analog or RF circuits, MCU supply rails, and battery-powered endpoint devices.

Application Guidelines for TPS77901DGKRG4 Family

The TPS77901DGKRG4 series is optimized for battery-operated systems where low quiescent current and rapid wake-up are necessary, such as handheld consumer electronics, industrial sensor modules, and communications interface cards. The regulator's PMOS architecture delivers a dropout voltage directly proportional to load current, which is especially advantageous for maximizing operating time in low-voltage battery designs.

A broad range of output capacitors are supported, but engineers must select ceramic types such as X7R or X5R for their temperature stability; high-capacitance Y5U or Z5U types should generally be avoided due to wide parameter variation across temperature. Proper output capacitance and ESR selection can minimize voltage droop during load steps, a foundational requirement in microprocessor and DSP power applications.

Configuring the Adjustable TPS77901DGKRG4 Regulator

For applications requiring non-standard supply voltages, the TPS77901 adjustable version allows precise output programming via a resistor divider. The output voltage follows:

$$ V_{O} = V_{ref} \times (1 + \frac{R1}{R2}) $$

Where $ V_{ref} $ is typically 1.1834 V. A divider current around 50 μA is recommended (R2 ≈ 30.1 kΩ) to balance power consumption and minimize error. Both resistors should be placed close to the FB/SENSE terminal for noise minimization, and higher-value resistors, which can introduce leakage-induced inaccuracies, should be avoided.

Protection Mechanisms and Dependability in TPS77901DGKRG4 Family

The TPS77901DGKRG4 includes robust protection mechanisms:

Back diode for output-to-input current flow during input undervoltage events (external current limiting suggested for extended reverse voltage operation)

Internal current limiting (typically 0.9 A) with linear foldback to prevent thermal runaway

Thermal shutdown and auto-recovery (cutoff above 150°C; reset below 130°C)

These features are critical for safeguarding sensitive electronics during power-up, undervoltage or overcurrent events, and ambient temperature excursions.

Power Loss and Thermal Control in the TPS77901DGKRG4 Family

Engineers must ensure that power dissipation stays within the specified limits to maintain rated operation. Calculations are as follows:

$$ P_{D(max)} = \frac{T_{Jmax} - T_A}{R_{\theta JA}} $$

$$ P_{D} = (V_I - V_O) \times I_O $$

Where $ T_{Jmax} $ is typically 125°C, $ T_A $ is ambient temperature, and $ R_{\theta JA} $ is the package thermal resistance. Designs requiring higher output current or voltage drop necessitate attention to layout, airflow, and heatsinking mechanisms to avoid premature activation of the thermal protection circuitry.

Alternative Models and Substitutes for TPS77901DGKRG4 Family

Engineers considering system upgrades or replacements may evaluate similar family devices for design reuse or expanded features. The TPS77901DGKRG4 series relates closely to:

TPS77918, TPS77925, TPS77930: Fixed output voltage versions with similar functional and pinout features

TPS773xx and TPS774xx series: For applications needing active-low enable, additional sequencing, or alternative supervisory functions

When assessing replacements, pin compatibility, output voltage programming range, quiescent current, dropout voltage, and supervisory logic characteristics should all be carefully compared to ensure seamless migration.

Conclusion

: TPS77901DGKRG4 Series in Modern Power Management

The TPS77901DGKRG4 low-dropout regulator series from Texas Instruments is a versatile solution for engineers demanding high-efficiency, reliable power management and system supervision in compact spaces. With its robust protection, broad capacitor compatibility, and ease of output programmability, the TPS77901DGKRG4 series stands out in applications where low quiescent current, precise voltage regulation, and integrated reset functionality are critical. Selection engineers and procurement professionals can confidently integrate this series into next-generation products, leveraging its technical advantages for continued innovation in embedded and portable systems.