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