描述 Description

The LM3677 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 2.7V to 5.5V. It provides up to 600 mA load current over the entire input voltage range. The LM3677 is configured to different fixed voltage output options as well as an adjustable output voltage version range from 1.2V to 3.3V. 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 ~ 80 mA to 600 mA 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 down), the device turns off and reduces battery consumption to 0.01 μA (typ.).The LM3677 is available in a lead-free (NOPB) 5-bump DSBGA package and 6-pin USON package. 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
? 600 mA maximum load capability
? 3 MHz PWM fixed switching frequency (typ.)
? Automatic PFM/PWM mode switching
? Available in 5-bump DSBGA package and 6-pin USON package
? Internal synchronous rectification for high efficiency
? Internal soft start
? 0.01 μA typical shutdown current
? Operates from a single Li-Ion cell battery
? Only three tiny surface-mount external components required (solution size less than 20 mm2)
? Current overload and thermal shutdown protection