The LT1533CS#PBF is a Switching Regulator designed to reduce conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are achieved by providing user control of the output switch slew rates. Voltage and current slew rates can be independently programmed to optimize switcher harmonic content versus efficiency. The LT1533 can reduce high frequency harmonic power by as much as 40dB with only minor losses in efficiency. The LT1533 utilizes a dual output switch current-mode architecture optimized for low noise topologies. The IC includes two 1A power switches along with all necessary oscillator, control and protection circuitry. Unique error amp circuitry can regulate both positive and negative voltages. The internal oscillator may be synchronized to an external clock for more accurate placement of switching harmonics. Protection features include cycle by cycle current limit protection, undervoltage lockout and thermal shutdown.
● Greatly reduced conducted and radiated EMI (<100µVP-P in typical application)
● Low switching harmonic content
● Independent control of switch voltage and current slew rates
● Regulates positive and negative voltages
● Easily synchronized to external clock
● Easier layout than with conventional switchers
● Outputs can be forced to 50% duty cycle for unregulated applications
● 12µA Typical low shutdown current