
Linear Technology
DESCRIPTION
The LT®1500 is an adaptive-frequency current mode stepup switching regulator with an internal power switch that is rated up to 700mA. In contrast to pulse skipping switching regulators, the LT1500 uses a current mode topology that provides lower noise operation and improved efficiency. Only at very light loads is Burst ModeTM activated to give high efficiency and micropower operation. High switching frequency (up to 500kHz) allows very small inductors to be used, along with ceramic capacitors if desired.
FEATURES
■ Low Noise Adaptive-Frequency Current Mode Operation Avoids Low Frequency Noise at Most Load Currents
■ Can Be Externally Synchronized (LT1500)
■ Micropower Quiescent Current: 200mA
■ Shutdown Current: 8mA Typ
■ Internal Loop Compensation
■ Low-Battery Comparator Active in Shutdown
■ Minimum Input Voltage: 1.8V Typ
■ Additional Negative Voltage Feedback Pin (LT1500)
■ Up to 500kHz Switching Frequency
■ Uses Low Profile, Low Cost Surface Mount Inductors
APPLICATIONS
■ Portable Instrumentation
■ Battery Operated Systems
■ PDA’s
■ Standby Power