LM2651 Datasheet | National Semiconductor

Description The LM2651 switching regulator provides high efficiency power conversion over a 100:1 load range (1.5A to 15m A). 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 15m A 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 k Hz fixed frequency internal oscillator. The high oscillator frequency allows the use of extremely small, low profile ponents. 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. Features n n n n n n n n n n n n 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 75mΩ 300k Hz 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 Applications n n n n n Personal digital assistants (PDAs) puter peripherals Battery-powered devices Handheld scanners High efficiency 5V conversion Typical Application DS100925-1 DS100925-15 Efficiency vs Load Current (VIN = 5V, VOUT = 3.3V) © 2000 National Semiconductor Corporation DS100925 .national. Connection...