LM2653 Datasheet | National Semiconductor

LM2653 1.5A High Efficiency Synchronous Switching Regulator November 1999 LM2653 1.5A High Efficiency Synchronous Switching Regulator General Description The LM2653 switching regulator provides high efficient power conversion over a 100:1 load range (1.5A to 15 m A). This feature makes the LM2653 an ideal fit in battery-powered applications. Synchronous rectification is used to achieve up to 97% efficiency. At light loads, the LM2653 enters a low power hysteretic or “sleep” mode to keep the efficiency high. In many applications, the efficiency still exceeds 80% at 15 m A load. A shutdown pin is available to disable the LM2653 and reduce the supply current to 7µA. All the power, control, and drive functions are integrated within the ICs. The ICs contain patented current sensing circuity for current mode control. This feature eliminates the external current sensing resistor required by other current-mode DC-DC converters. The ICs have a 300 k Hz fixed frequency internal oscillator. The high oscillator frequency allows the use of extremely small, low profile ponents. Protection Features include thermal shutdown, input undervoltage lockout, adjustable soft-start, cycle by cycle current limit, output overvoltage and undervoltage protections. n n n n n n n n n n n n 4V to 14V input voltage range 1.5V to 5.0V adjustable output voltage 0.1Ω Switch On Resistance 300 k Hz fixed frequency internal oscillator 7 µA shutdown current Patented current sensing for current mode control Input undervoltage lockout Output overvoltage shutdown protection Output undervoltage shutdown protection Adjustable soft-start Adjustable PGOOD delay Current limit and thermal shutdown Applications n n n n n n n n Webpad Personal digital assistants (PDAs) puter peripherals Battery-powered devices Notebook puter video supply Handheld scanners GXM I/O and core voltage High efficiency 5V conversion Features n Efficiency up to 97% Typical Application Efficiency vs Load Current (VIN = 5V, VOUT...