LM3679中文资料用于超低截面应用的 3MHz、350mA 微型降压直流/直流转换器数据手册TI规格书

描述 Description

The LM3679 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.5V to 5.5V. It provides up to 350mA load current, over the entire input voltage range. The LM3679 output voltage can be configured to 1.2V, 1.5V, or 1.8V.

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between PWM low-noise and PFM low-current mode offers improved system control. During PWM mode operation, the device operates at a fixed-frequency of 3 MHz (typ). PWM mode drives loads from ~ 80mA to 350mA max. Hysteretic PFM mode extends the battery life by reducing the quiescent current to 16 µA (typ) during light load and standby operation. Internal synchronous rectification provides high efficiency. In shutdown mode (Enable pin pulled low), the device turns off and reduces battery consumption to 0.01 µA (typ).

The LM3679 is available in a lead-free (No PB) 5-bump micro SMD package, 0.6mm height, and in an ultra thin 0.3mm height UR package. Using the UR package along with specific external components, allows for a low profile solution size with a max height of 0.55mm. A switching frequency of 3 MHz (typ) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required. .

特性 Features

• 16 µA typical quiescent current
• 3 MHz PWM fixed switching frequency (typ)
• Available in 5-bump micro SMD package and UR package
• Internal soft start
• Operates from a single Li-Ion cell battery
• Three external components required for typical applications
• Low profile solution (0.55mm max height, includes four external components)