The RT9161-40CX is a low dropout (LDO) voltage regulator from Richtek USA Inc. It is engineered to provide a stable and accurate 4.0V output. Characterized by low quiescent current, high output accuracy, and excellent transient response, this LDO regulator is ideal for numerous battery-operated and portable device applications. Its precise voltage regulation improves overall system stability and reliability.

Applications:

• Cellular Phones: Powering core components like the microcontroller and RF transceiver that require a consistent 4.0V.
• Cordless Phones: Provides regulated power for baseband and RF circuitry.
• PDAs: Ensures stable power supply to the processor, memory, and display.
• MP3 Players: Supplies a clean and reliable voltage for audio processing and control circuits.
• GPS Devices: Powers the GPS receiver and navigation processing unit.
• Wireless LANs: Providing stable voltage to the WLAN module and associated components.
• Bluetooth Devices: Regulates voltage for Bluetooth modules used in wireless communication.
• Digital Cameras: Supplying a stable voltage for image sensors and the image processing unit.

Features:

• Low Dropout Voltage: Enables efficient operation with a minimal voltage difference between input and output.
• High Output Accuracy: Provides a precise and stable 4.0V output, enhancing operational reliability.
• Low Quiescent Current: Reduces power consumption in standby or lightly loaded conditions.
• Short-Circuit Protection: Safeguards both the regulator and the load against damage from short circuits.
• Over-Temperature Protection: Prevents thermal damage by disabling the regulator if its temperature goes beyond safe limits.
• Stable with Ceramic Capacitors: Functions reliably with low-ESR ceramic output capacitors for compact designs.
• Enable/Disable Control: Permits remote control of the regulator's on/off state, reducing power usage in standby mode.

Benefits:

• Extended Battery Life: Low quiescent current and low dropout voltage lead to prolonged battery life in portable devices.
• Reliable Operation: High output accuracy and protective functions ensure a dependable power supply.
• Simplified Design: Stability with ceramic capacitors simplifies the layout process.
• Reduced Power Consumption: Enable/disable control minimizes power draw during inactive periods.
• Enhanced Safety: Short-circuit and over-temperature protection prevent damage.

Additional Details:

The RT9161-40CX is generally offered in a compact surface-mount package like SOT-23-5. It is essential to consult the datasheet for specific details regarding dropout voltage at various load currents and temperatures. The regulator is designed with excellent line and load regulation, contributing to a stable output voltage even under changing operating conditions.