Power Management ICs

PWM Control & PWM/PFM Control High Frequency Step-Up Switching Regulator (DC-DC Converter ICs) S-8340/8341 Series

The S-8340/8341 series consists of CMOS step-up switching regulator (DC-DC Converter ICs)-controllers with PWM control (S-8340) and PWM/PFM switched control (S-8341). These devices contain a reference voltage source, oscillation circuit, error amplifier, phase compensation circuit, PWM control circuit, and other components. Since the oscillation frequency is a high 300 kHz or 600 kHz, with the addition of a small external component, the ICs can function as step-up switching regulators with high efficiency and large output current. The speed of the output stage is enhanced so that the Nch power MOS with a low ON resistance can be switched quickly.
The S-8340 provides low-ripple power, high-efficiency, and excellent transient characteristics thanks to a PMW control circuit capable of varying the duty ratio linearly from 0% to 82% and optimized error amplifier, and phase compensation circuit.
The S-8341 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 ICs serve as ideal main power supply units for portable devices when coupled with the 8-pin TSSOP package and high oscillation frequencies.
we offer a simulation software as a support tool for circuit design where switching regulator (DC-DC Converter ICs) is used.


Oscillation frequency
600 kHz (A & B series), 300 kHz (C & D series).
Output voltage
Internally selectable in the range 2.5V to 6.0V in steps of 0.1V (Output voltage fixed output type)
Output voltage precision
Output voltage external setting (FB) type available. FB terminal voltage (VFB) 1.0V
The only peripheral components that can be used with this IC are a transistor, a coil, a diode, capacitors (3), and a resistor.
Duty ratio
0% to 82% typ. PWM control (S-8340)
27% to 82% typ. PWM/PFM-switched control (S-8341, A & B series)
21% to 82% typ. PWM/PFM-switched control (S-8341, C & D series)
Low-voltage operation
Oscillation can start when VDD=0.9V.
Built-in current limiting circuit
Can be set with an external resistor (RSENSE).
Soft-start function
Can be set with an external capacitor (CSS).
With a power-off function.
Lead-free products


  • Power supplies for PDAs, electronic notebooks, and portable devices
  • Power supplies for audio equipment, including portable CD players, portable MD players and headphone stereo equipment
  • Main and sub power supplies for notebook computers and peripheral equipment
  • Fixed voltage power supply for cameras, video equipment and communications equipment

Standard Circuit

Standard Circuit