650mA Micropower Low Noise Boost Converter with Output Disconnect

Description: The LT3495, LT3495B, LT3495-1, and LT3495B-1 are low-noise boost converters equipped with an integrated power switch, feedback resistor, and output disconnect circuitry. These devices manage power delivery by adjusting both the peak inductor current and the switch off-time, resulting in low output voltage ripple and high efficiency across a broad load range. For the LT3495 and LT3495-1 models, the switch off-time is limited to a fixed level, ensuring that the switching frequency remains above the audio band throughout the entire load range. These components feature a high-performance NPN power switch with a current limit of 650mA for the LT3495 and LT3495B, and 350mA for the LT3495-1 and LT3495B-1. The quiescent current is notably low at 60 µA, which can be further reduced to 0.1 µA during shutdown. The internal disconnect circuitry enables the output voltage to be isolated from the input during shutdown. An auxiliary reference input (CTRL pin) allows an override of the internal 1.235V feedback reference with a lower value, providing full control over the output voltage during operation. The LT3495 series is available in a compact 10-lead, 3mm x 2mm DFN package. Pricing listed is for budgetary use only, in US dollars, and is subject to change. International pricing may vary due to local duties, taxes, and exchange rates. For specific pricing or delivery quotes, contact a local Linear Technology sales office or authorized distributor. Free demo boards are available for qualified customers; inquiries should be directed to local sales offices or distributors. Certain demo boards can also be purchased via credit card on the website, intended for evaluation purposes only. It is the customer's responsibility to ensure proper and reliable operation in the actual end application.

The LT3495 series of boost converters is designed to provide efficient power management solutions in compact applications where space is at a premium. The integrated features of these converters, including the power switch and feedback resistor, simplify the design process, reducing the need for external components. The low quiescent current of 60 µA makes these devices particularly suitable for battery-operated systems, where power conservation is critical. Additionally, the ability to isolate the output voltage during shutdown enhances the overall safety and reliability of the circuit.

The CTRL pin serves as a critical feature for applications requiring precise voltage control. By allowing an external voltage to override the internal reference, designers can easily customize the output voltage to meet specific system requirements. This flexibility is especially beneficial in applications such as portable devices, where varying load conditions may necessitate adjustments to the output voltage.

The choice of a high-performance NPN power switch ensures that the LT3495 series can handle significant load currents while maintaining low output voltage ripple. This is particularly important in sensitive analog applications where noise can adversely affect performance. The fixed off-time switching mechanism contributes to the stability of the output voltage, preventing it from entering the audible range, which is essential for applications involving audio devices.

Furthermore, the compact DFN package allows for straightforward integration into printed circuit boards (PCBs), making it ideal for space-constrained designs. Overall, the LT3495 series provides a robust solution for a wide range of applications, including portable electronics, telecommunications, and automotive systems, where efficient and reliable power management is a necessity.The LT3495/LT3495B/LT3495-1/LT3495B-1 are low noise boost converters with integrated power switch, feedback resistor and output disconnect circuitry. The parts control power delivery by varying both the peak inductor current and switch off-time. This novel* control scheme results in low output voltage ripple as well as high efficiency over a wide

load range. For the LT3495/LT3495-1, the off-time of the switch is not allowed to exceed a ¬xed level, guaranteeing the switching frequency stays above the audio band for the entire load range. The parts feature a high performance NPN power switch with a 650mA and 350mA current limit for the LT3495/LT3495B and LT3495-1/LT3495B-1 respectively.

The quiescent current is a low 60 A, which is further reduced to 0. 1 A in shutdown. The internal disconnect circuitry allows the output voltage to be isolated from the input during shutdown. An auxiliary reference input (CTRL pin) overrides the internal 1. 235V feedback reference with any lower value allowing full control of the output voltage during operation.

The LT3495 series are available in a tiny 10-lead 3mm G— 2mm DFN package. * The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer`s responsibility to verify proper and reliable operation in the actual end application.