Seiko Instruments S-8355
The S-8355/56/57/58 Series is a CMOS step-up switching regulator controller which mainly consists of a reference voltage source, an oscillation circuit, an error amplifier, a phase compensation circuit, a PWM control circuit (S-8355/57 Series) and a PWM/PFM switching control circuit (S-8356/58 Series). With an external low-ON-resistance Nch Power MOS, this product is ideal for applications requiring high efficiency and a high output current. The S-8355/57 Series realizes low ripple, high efficiency, and excellent transient characteristics due to its PWM control circuit whose duty ratio can be varied linearly from 0 to 83% (from 0 to 78% for 250 kHz, 300 kHz, and 600 kHz models), an excellently designed error amplifier and a phase compensation circuits.