LTC1729CMS8-8.2#PBF

Introduction: The LTC1729CMS8-8.2#PBF is a multi-phased synchronous buck regulator designed to provide high efficiency, low output voltage ripple and fast transient response, while providing seamless phase transitions. This device is ideal for applications where space is at a premium, such as in notebook and handheld computers, as well as battery powered systems, including communications and consumer electronics.

Application Field: The LTC1729CMS8-8.2#PBF is primarily used in battery charging applications. Itcan be used to charge Li-ion, Li-polymer, NiMH, NiCd, LiFePO4 and lead-acid batteries. The device is also well suited for use in point-of-load regulators, namely linear and DC/DC converters. It can be used in step-up, step-down and flyback topologies, providing an adjustability range of up to 2.5 V to 24 V. Additionally, it can also be used for powering FPGAs/PLDs, CPUs/MCUs and ASICs.

Working Principle: The LTC1729CMS8-8.2#PBF is a synchronous buck regulator. In the first stage of operation, the input voltage is stepped down by the P-channel MOSFETs (Q1 and Q2) and inductor, forming a buck converter. As the inductor current increases, the voltage across the inductor (VIND) also increases, which causes the P-channel MOSFETs to switch and reduce the duty-cycle by which Q1 and Q2 conduct. This reduces the peak current of the inductor and thus the output voltage is regulated. The output voltage is then adjusted and regulated by the external loop control amplifier. The second stage of operation is a synchronous rectifier, where the rectifier (Q3) is on while the P-channel MOSFETs are off. Finally, the output voltage is adjusted and monitored by the external loop control amplifier, providing a Regulation Transconductance Amplifier (RTA) that can be set to a set-point by a resistor divider at the output.

Conclusion: The LTC1729CMS8-8.2#PBF is a high efficiency and low voltage ripple synchronous buck regulator. Its application field is mainly in battery charging, linear and DC/DC converters, step-up, step-down and flyback topologies, as well as powering FPGAs/PLDs, CPUs/MCUs, and ASICs. Its working principle is that of a synchronous buck regulator, where the input voltage is stepped down by the P-channel MOSFETs and inductor, forming a buck converter, and the output voltage is adjusted and regulated by the external loop control amplifier. With its versatile application and easy to use design, the LTC1729CMS8-8.2#PBF is an excellent choice for battery charging requirements.