The LM2651 switching regulator provides high efficiency power conversion over a 100:1 load range (1.5A to 15mA). This feature makes the LM2651 an ideal fit in battery-powered applications that demand long battery life in both run and standby modes.

Synchronous rectification is used to achieve up to 97% efficiency. At light loads, the LM2651 enters a low power hysteretic or “sleep” mode to keep the efficiency high. In many applications, the efficiency still exceeds 80% at 15mA load. A shutdown pin is available to disable the LM2651 and reduce the supply current to less than 10µA.

The LM2651 contains a patented current sensing circuitry for current mode control. This feature eliminates the external current sensing resistor required by other current-mode DC-DC converters.

The LM2651 has a 300 kHz fixed frequency internal oscillator. The high oscillator frequency allows the use of extremely small, low profile components.

A programmable soft-start feature limits current surges from the input power supply at start up and provides a simple means of sequencing multiple power supplies.

Other protection features include input undervoltage lockout, current limiting, and thermal shutdown.

• Ultra High Efficiency up to 97%
• High Efficiency Over a 1.5A to Milliamperes Load Range
• 4V to 14V Input Voltage Range
• 1.8V, 2.5V, 3.3V, or ADJ Output Voltage
• Internal MOSFET Switch with Low RDS(on) of 75m?
• 300kHz Fixed Frequency Internal Oscillator
• 7µA Shutdown Current
• Patented Current Sensing for Current Mode Control
• Input Undervoltage Lockout
• Adjustable Soft-Start
• Current Limit and Thermal Shutdown
• 16-pin TSSOP Package