Texas Instruments LP2988IM-5.0/NOPB

Product Summary

The Texas Instruments LP2988IM-5.0/NOPB is a surface-mount, positive fixed-output linear voltage regulator delivering 5V at up to 200 mA with exceptional precision and low-noise performance. Part of the LP2988 family, this 8-SOIC device is engineered to meet the needs of noise-sensitive and power-constrained applications common in modern portable electronic systems. Engineered on TI's Vertically Integrated PNP (VIP) process, the LP2988IM-5.0/NOPB is optimized for areas such as cellular handsets, portable instrumentation, laptops, and audio-visual electronics where stability, size, and reliability are crucial.

Main Functions and Advantages of the LP2988IM-5.0/NOPB

The features of the LP2988IM-5.0/NOPB position it as a high-value solution for engineers seeking robust LDO performance in compact systems:

Ultra Low Dropout Operation: With a typical dropout voltage of only 180 mV at 200 mA, the LP2988IM-5.0/NOPB minimizes power loss, supporting longer battery life and reliable regulation close to the supplied voltage.

Noise Reduction: The LP2988 variant features a dedicated BYPASS pin. An external low-leakage capacitor here significantly lowers output voltage noise—a critical advantage for RF, analog, or audio circuitry.

Low Standby Consumption: In shutdown mode, quiescent current drops below 2 μA, making it suitable for power-sensitive designs.

Highly Accurate Output: The "A" grade variant, available for the LP2988IM-5.0/NOPB, ensures output voltage accuracy within ±0.5% at room temperature, supporting consistently reliable system design.

Flexible Power-On Reset (POR): A programmable reset delay function can be implemented with a single external capacitor, providing predictable system startup behavior and reliable error flagging through the ERR/RESET output.

Load Capability: Continuous 200 mA output current is guaranteed, with peak capability exceeding 250 mA.

Wide Supply and Thermal Range: The device operates over an input range up to 16V and a -40°C to +125°C junction temperature, suiting harsh environments and diverse application types.

Comprehensive Protection: Overtemperature and overcurrent protection are built-in, enhancing the LP2988IM-5.0/NOPB's robustness in demanding applications.

Compact Surface-Mount Packaging: Available in SOIC-8, VSSOP-8, and WSON packages, the regulator enables high-density board designs.

Electrical Specifications and Common Performance of the LP2988IM-5.0/NOPB

Engineers and system architects will appreciate the LP2988IM-5.0/NOPB's tightly controlled electrical parameters:

Output Voltage: Fixed at 5.0V (nominal), meeting the requirements of most logic, microcontroller, and analog subsystems.

Dropout Voltage: 180 mV (typical) at a full 200 mA load ensures stable 5V output even as supply drops to 5.18V.

Ground Pin Current: 1 mA typical at 200 mA output, minimizing power overhead in portable systems. At lighter loads (10 mA), ground current drops to 200 μA (typical).

Output Noise: With a bypass capacitor (on BYPASS pin), output noise is significantly reduced compared to standard regulators—a key consideration for sensitive analog or RF stages.

Output Accuracy: ±0.5% for the “A” grade, and ±1% for the standard grade, both specified at room temperature.

Quiescent Current: Less than 2 μA in shutdown, supporting low-power standby states.

Overcurrent and Overtemperature Limits: Protects itself and downstream circuitry from fault-induced damage.

Guidelines for Implementing the LP2988IM-5.0/NOPB in Applications

Proper implementation of the LP2988IM-5.0/NOPB is vital for stable operation and optimal noise suppression. Key recommendations for design engineers include:

Input Capacitor: A minimum of 2.2 μF (ceramic or tantalum) should be placed within 0.5 inches of the VIN pin to ground for supply filtering and stability.

Output Capacitor: At least 4.7 μF is required, with careful attention to ESR values—too high or too low ESR can cause instability. Tantalum capacitors are generally preferred due to stable ESR across temperature; if ceramic is used, a series resistor may be needed to introduce adequate ESR.

BYPASS Capacitor: For noise-sensitive applications, connect a low-leakage, high-quality (e.g., COG/NPO ceramic) capacitor to the BYPASS pin, observing manufacturers’ leakage current data.

Power-On Reset Delay: Connect an external capacitor to the DELAY pin to program the length of the POR delay. The capacitor should be less than 1 μF and must exhibit low leakage to ensure reliable timing.

Shutdown Control: The Shutdown pin (S/D) allows for logic-controlled enabling/disabling. If unused, tie S/D to VIN to maintain constant output.

Reverse Voltage Protection: If the output might exceed the input voltage, a Schottky diode from VIN to VOUT is needed to protect against potential regulator damage.

Layout: Minimize parasitic resistance and inductance by placing all decoupling capacitors and the bypass cap as close as possible to the device pins, using short, wide PCB traces connected to a clean analog ground.

Packaging, Thermal Management, and Assembly Info for the LP2988IM-5.0/NOPB

Considerable attention is given to mechanical integration, with the LP2988IM-5.0/NOPB offered in space-saving SOIC-8, VSSOP-8, and WSON-8 packages.

SOIC-8 offers 160°C/W junction-to-ambient thermal resistance; VSSOP-8 is rated for 200°C/W. The WSON package provides enhanced thermal performance, depending on PCB layout, copper area, and the use of thermal vias.

For all packages, close attention should be paid to thermal dissipation—especially in high-load or high-temperature environments. The PCB layout should follow the manufacturer’s recommendations for solder pad dimensions and via placement under exposed pads to optimize heat flow.

Assembly processes (e.g., stencil design for solder paste application) should accommodate the recommended package outlines and guidelines from IPC-7351 and related standards.

Alternative or Comparable Models to the LP2988IM-5.0/NOPB

For engineers considering second-sourcing or evaluating alternatives, the following are potential equivalents or suitability-comparable models to the LP2988IM-5.0/NOPB:

LP2987: A related TI family member with similar electrical characteristics, offering multiple output configurations.

Other manufacturers also offer ultra-low dropout regulators targeting similar voltage, supply, and noise performance specs. Selection should be based on factors such as pin-compatibility, dropout voltage, noise performance, and available package options.

Conclusion

The Texas Instruments LP2988IM-5.0/NOPB stands out as a robust, precision, low-noise 5V LDO regulator well-suited to demanding portable and noise-sensitive applications. By combining tight output regulation, ultra-low dropout, programmable POR, and effective output noise suppression, it offers design engineers a reliable solution for contemporary power management challenges. When board space, low quiescent current, and output purity are priorities, careful implementation of the LP2988IM-5.0/NOPB can yield substantial performance and system reliability gains. The breadth of package choices and comprehensive protection features further ensure successful deployment across a broad spectrum of products, from consumer electronics to industrial portable instrumentation.