S-8540

S-8540/8541 Series www.ablicinc.com © ABLIC Inc., 2000-2010 STEP-DOWN, 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER Rev.4.0_02 The S-8540/8541 Series is a family of CMOS step-down switching regulator controllers with PWM control (S8540 Series) and PWM/PFM switchover control (S-8541 Series). These devices consist of a reference voltage source, oscillation circuit, an error amplifier, phase compensation circuit, PWM control circuit, current limit circuit. A high efficiency and large current switching regulator is realized with the help of small external components due to the high oscillation frequency, 300 kHz and 600 kHz. The S-8540 Series provides low-ripple voltage, high efficiency, and excellent transient characteristics which come from the PMW control circuit capable of varying the duty ratio linearly from 0 to 100%, the optimized error amplifier, and the phase compensation circuit. The S-8541 Series operates under PWM control when the duty ratio is 2...