|
Features
Sub-miniature 10-pin micro SMD package
Only three tiny surface-mount external components required
Uses small ceramic capacitors.
Internal soft start
Current overload protection
No external compensation required
Description The LM2612 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Lithium-Ion cell.
It provides up to 400mA (300mA for B grade), over an input voltage range of 2.8V to 5.5V. Pin programmable output voltages
of 1.05V, 1.3V, 1.5V or 1.8V allow adjustment for MPU voltage options without board redesign or external feedback resistors.
The device has three pin-selectable modes for maximizing battery life in
mobile phones and similar portable applications. Low-noise PWM mode offers 600kHz fixed-frequency operation to reduce interference
in RF and data acquisition applications during full-power operation. In PWM mode, internal synchronous rectification provides
high efficiency (91% typ. at 1.8VOUT). A SYNC input allows synchronizing the switching frequency in a range of 500kHz to 1MHz to avoid noise from intermodulation
with system frequencies. Low-current hysteretic PFM mode reduces quiescent current to 150 µA (typ.) during system standby.
Shutdown mode turns the device off and reduces battery consumption to 0.1µA (typ.). Additional features include soft start
and current overload protection.
The LM2612 is available in a 10 pin micro SMD packge. This package uses National's wafer level chip-scale micro SMD technology
and offers the smallest possible size. Only three small external surface-mount components, an inductor and two ceramic capacitors
are required.
Key Specification
Operates from a single LiION cell (2.8V to 5.5V)
Pin programmable output voltage (1.05V, 1.3V, 1.5V and 1.8V)
400mA maximum load capability (300mA for B grade)
±2% PWM mode DC output voltage precision
2mV typ PWM mode output voltage ripple
150 µA typ PFM mode quiescent current
0.1µA typ shutdown mode current
Internal synchronous rectification for high PWM mode efficiency (91% at 2.8VIN, 1.8VOUT)
600kHz PWM mode switching frequency
SYNC input for PWM mode frequency synchronization from 500kHz to 1MHz
Applications
Mobile Phones
Hand-Held Radios
Battery Powered Devices
|
|
