LM3677

LM3677 3MHz, 600mA Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits March 2007 LM3677 3MHz, 600mA Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits General 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 600mA load current, over the entire input voltage range. The LM3677 is configured to four output voltages of 1.3V, 1.5V, 1.8V and 2.5V. 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 600mA 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 (NO PB) 5-bump micro SMD 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. Features ■ ■ ■ ■ ■ ■ ■...