Power Management ICs

Super-Small Package PWM Control, PWM/PFM Control Step-Up Switching Regulator (DC-DC Converter ICs) S-8353/8354 Series

The S-8353/54 Series is a CMOS step-up switching regulator (DC-DC Converter ICs) which mainly consists of a reference voltage source, an oscillation circuit, a power MOS FET, an error amplifier, a phase compensation circuit, a PWM controller (S-8353) and a PWM/PFM switching controller (S-8354).
The step-up switching regulator (DC-DC Converter ICs) can be configured simply by attaching a coil, capacitor, and diode externally. In addition to the above features, the small package and low power consumption of this series make it ideal for portable device applications requiring high efficiency.
The S-8353 Series realizes low ripple, high efficiency, and excellent transient characteristics due to its PWM controller, which can vary the duty ratio linearly from 0% to 83% (from 0% to 78% for 250 kHz models), optimally-designed error amplifier, and phase compensation circuits.
The S-8354 Series features a PWM/PFM switching controller that can switch the operation to a PFM controller with a duty ratio is 15% under a light load to prevent a decline in the efficiency due to the IC operating current.

Features

Low voltage operation
Start-up is guaranteed from 0.9 V (IOUT = 1 mA )
Low current consumption
During operation 18.7 µA (3.3 V, 50 kHz, typ.),
During shutdown 0.5 µA (max.)
Duty ratio
Built-in PWM/PFM switching control circuit (S-8354)
15 to 83% (30 kHz and 50 kHz models), 15 to 78% (250 kHz models)
External parts
Coil, capacitor, and diode
Output voltage
Can be set in 0.1 V steps between 1.5 and 6.5 V (for VDD / VOUT separate types) or 2.0 and 6.5 V (for other than VDD / VOUT separate types).
Accuracy of ±2.4%.
Oscillation frequency
30, 50, and 250 kHz
Soft start function
6 ms (50 kHz, typ.)
Lead-free products

Applications

  • Power supplies for portable equipment such as digital cameras, electronic notebooks, and PDAs
  • Power supplies for audio equipment such as portable CD/MD players
  • Constant voltage power supplies for cameras, video equipment, and communications equipment
  • Power supplies for microcomputers

Standard Circuit

Standard Circuit