- 16μA typical quiescent current
- 350 mA maximum load capacity
- 3 MHz fixed switching frequency PWM (typical)
- Automatic PFM/PWM mode switching
- Available in 5-ball micro SMD package and UR package
- Internal synchronous rectification for high efficiency
- Internal soft start
- 0.01μA typical shutdown current
- Operates on single-cell lithium-ion batteries
- Current overload and thermal shutdown protection
- Typical applications for three external components
- Low profile solution (0.55 mm maximum height, including 4 external components)
illustrate
The LM3679 step-down DC-DC converter is optimized for powering from a single-cell Li-Ion battery and an ultra-low voltage circuit from 2.5V to 5.5V to an input voltage rail. It can deliver up to 350mA of load current over the entire input voltage range. The output voltage of the LM3679 can be set to 1.2V, 1.5V or 1.8V.
The device offers superior functionality and performance in portable applications similar to mobile phones and complex power management systems. Intelligent switching between automatic PWM low noise and PFM low current modes provides improved system control. Operating in PWM mode, the device operates at a fixed frequency of 3 MHz (typical). PWM mode drives from −80 mA maximum load to 350mA. Hysteretic PFM mode extends battery life at light loads, reduced standby operation, and quiescent current of 16μA (typical). Internal synchronous rectification provides high efficiency. In shutdown mode (the enable pin is pulled low), the device shuts down, reducing battery consumption to 0.01μA (typical).
The LM3679 is available in a lead-free (PB-free) 5 solder ball micro SMD package with 0.6mm height and an ultra-thin 0.3mm height UR package. The use of a UR package with specific external components allows for low profile with a maximum height of 0.55 mm for the solution size. A switching frequency of 3 MHz (typical) allows the use of tiny surface mount components. Only three external surface mount components, an inductor and two ceramic capacitors, are required. 。
apply
- mobile phone
- Pocket PC
- MP3 player
- W - LAN
- Portable instrument
- Digital cameras
- Portable hard drives
|