Overview: .. Rev.3.1_00 STEP-UP, 600 kHz, PWM CONTROL OR PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER S-8340/8341 Series The S-8340/8341 Series is a CMOS step-up switching regulator controller which mainly consists of a reference voltage source, oscillation circuit, error amplifier, phase pensation circuit, PWM control circuit (S-8340 Series), and PWM/PFM switching control circuit (S-8341 Series). Since the oscillation frequency is a high 300 kHz or 600 kHz, with the addition of a small external part, the S-8340/8341 Series functions as a highly efficient step-up switching regulator with a high output current. The speed of the output stage is enhanced so that the N-channel power MOS with a low on-resistance can be switched quickly. The S-8340 Series realizes low ripple, high efficiency, and excellent transient characteristics thanks to a PMW control circuit capable of varying the duty ratio linearly from 0 to 82%, optimized error amplifier, and phase pensation circuit. The S-8341 Series contains a PWM/PFM switching control circuit so that it operates using PWM control with a duty ratio of 27% or higher and using PFM control with a duty ratio of lower than 27% to ensure high efficiency in all load ranges. These S-8340/8341 Series serve as ideal main power supply units for portable devices when coupled with the 8-Pin TSSOP package and high oscillation frequencies.
