LM2608 Datasheet | National Semiconductor

Description 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 400m A 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 (300m A) for low voltage version or 1.5V/1.8V (400m A) 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 plex power management systems. Pin-selectable PWM lownoise 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 500k Hz 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 m A 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 surfacemount ponents. Only four small external surface-mount ponents, an inductor and three ceramic capacitors are required. Pin selectable output voltage eliminates the need for bulky external feedback resistors. Key Specifications n Operates from a single Li ION cell (2.8V to 5.5V) n Pin selectable output voltage (1.5V/1.8V or 1.3V/1.5V versions), without external feedback resistors n 400m A maximum load...