onsemi

LM7909CT

LM7909CT Description

The LM7909CT is a negative voltage regulator designed to provide a stable -9V output with a fixed output type. Manufactured by onsemi, this linear voltage regulator is housed in a through-hole TO220-3 package and is suitable for a wide range of applications requiring a reliable and efficient power supply solution. Despite being marked as obsolete, the LM7909CT remains a viable option for existing designs and legacy systems.

LM7909CT Features

• Output Type: Fixed at -9V, ensuring a stable and consistent power supply.
• Output Current: Capable of delivering up to 1A, making it suitable for applications requiring moderate power levels.
• Number of Regulators: Single regulator design simplifies circuit design and reduces component count.
• Output Configuration: Negative output voltage, ideal for applications requiring a negative supply rail.
• Voltage Dropout: A maximum dropout voltage of 2V at 1A (typical) ensures efficient operation even at lower input voltages.
• Operating Temperature: Wide temperature range of 0°C to 125°C, suitable for various environmental conditions.
• Quiescent Current: Low quiescent current of 6 mA minimizes power consumption during idle states.
• Power Supply Rejection Ratio (PSRR): 60dB at 120Hz, providing excellent noise rejection and stable output voltage.
• Protection Features: Over-temperature and short-circuit protection enhance reliability and protect against common fault conditions.
• Moisture Sensitivity Level (MSL): Level 1 (unlimited), indicating the device is not sensitive to moisture, simplifying handling and storage.
• Package: Supplied in a tube package, facilitating easy handling and integration into through-hole PCB designs.

LM7909CT Applications

The LM7909CT is ideal for applications requiring a stable -9V supply, such as:

• Analog Circuits: Powering operational amplifiers, analog-to-digital converters (ADCs), and other analog components that require a negative supply rail.
• Audio Equipment: Providing a clean and stable power supply for audio amplifiers and preamplifiers, ensuring high-fidelity performance.
• Industrial Control Systems: Supplying power to sensors, actuators, and control circuits in industrial environments.
• Medical Devices: Ensuring reliable power supply for medical equipment that requires a negative voltage rail.
• Legacy Systems: Replacing or maintaining existing systems that utilize the LM7909 series, ensuring compatibility and continuity.

Conclusion of LM7909CT

The LM7909CT, despite its obsolete status, remains a robust and reliable choice for applications requiring a stable -9V supply. Its low dropout voltage, low quiescent current, and comprehensive protection features make it a versatile and efficient solution. The wide operating temperature range and moisture sensitivity level of 1 ensure that it can be used in diverse environments without compromising performance. For designers and engineers working with legacy systems or specific applications that require a negative voltage rail, the LM7909CT offers a proven and dependable power supply option.