LM2608  Product Folder

The LM2608 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Lithium-Ion cell. It provides up to 400mA over an input voltage range of 2.8V to 5.5V. Operating from a 1.35V reference, this device provides pin-selectable output voltages of 1.3V/1.5V (300mA) for low voltage version or 1.5V/1.8V (400mA) for high voltage version. This allows adjustment for DSP or CPU voltage options, as well as dynamic output voltage switching for reduced power consumption. Internal synchronous rectification provides high efficiency.

The LM2608 offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Pin-selectable PWM low-noise and linear micropower modes offer improved system control for maximizing battery life. During full power operation, fixed-frequency PWM mode reduces interference in RF and data acquisition applications by minimizing noise harmonics at sensitive IF and sampling frequencies. A SYNC input allows synchronizing the switching frequency in a range of 500kHz to 1MHz to avoid noise from intermodulation with system frequencies. Linear operation reduces quiescent current to 20µA (typ) during system standby for extended battery life. It provides up to 3 mA in the linear mode. Shutdown reduces battery consumption to 0.02µA (typ.).

The LM2608 is available in a 10 pin Micro SMD package. This package uses National's wafer level chip-scale Micro SMD technology and offers the smallest possible size. A high switching frequency (600KHz) allows use of tiny surface-mount components. Only four small external surface-mount components, an inductor and three ceramic capacitors are required. Pin selectable output voltage eliminates the need for bulky external feedback resistors.

• Sub-miniature 10-pin thin Micro SMD package
• Only four tiny surface-mount external components required
• Uses small ceramic capacitors
• Internal soft start
• Current and Thermal shutdown protection
• No external compensation required

• Operates from a single LiION cell (2.8V to 5.5V)
• Pin selectable output voltage (1.5V/1.8V or 1.3V/1.5V versions), without external feedback resistors
• 400mA maximum load capability
• ±1% PWM mode DC output voltage precision (Excluding external reference tolerance)
• 5mV typ PWM mode output voltage ripple
• 20 µA typ quiescent current (Linear Mode)
• 0.02µA typ shutdown mode current
• Internal synchronous rectification for high efficiency (91% at 2.8V_IN, 1.8V_OUT)
• 600kHz PWM mode switching frequency
• SYNC input for PWM mode frequency synchronization from 500kHz to 1MHz
• 15% accuracy for F_OSC and I_lim

• Mobile Phones
• Hand-Held Radios
• Battery Powered Devices