REGULATOR CONTROLLER. S-8533 Datasheet
STEP-DOWN, SYNCHRONOUS PWM CONTROL
SWITCHING REGULATOR CONTROLLER
The S-8533 Series is a synchronous PWM control CMOS step-down
switching regulator controller that includes a reference voltage source,
synchronous circuit, oscillation circuit, error amplifier, phase
compensation circuit, and PWM controller.
An efficient step-down switching regulator can be realized simply by
adding external P-channel and N-channel power MOS FETs, one coil,
and three capacitors.
Since the oscillation frequency is a high 300 kHz, the S-8533 can be
used to configure a high efficiency step-down switching regulator
capable of driving high output current using small external parts and a
3 to 10% increase in efficiency is obtained compared to conventional
step-down switching regulators.
The 8-Pin TSSOP package and high oscillation frequency make the S-
8533 ideal as the main power supply for portable devices.
• Synchronous rectification system realizing high efficiency (typ. 94%)
• Use at maximum duty ratio = 100% and use of a battery up to maximum life is possible by using P-channel and N-
channel power MOS FETs externally.
• Oscillation frequency : 300 kHz typ.
• Input voltage :
2.7 to 16.0 V
• Output voltage :
1.3 to 6.0 V, selectable in 0.1 V steps
• Output voltage accuracy : ±2.0%
• Soft-start function set by an external capacitor (CSS)
• Shutdown function
• Small package :
• Lead-free products
• Constant voltage power supply for hard disks and DVD drivers
• Power supplies for portable devices, such as digital cameras, PDAs, electronic organizers, and cellular phones
• Main or sub power supply for notebook PCs and peripherals
• Constant voltage power supply for cameras, video equipment, and communication equipment
Seiko Instruments Inc.
www.DaStaTSEhePet-4DU.OcoWm N, SYNCHRONOUS PWM CONTROL SWITCHING REGULATOR CONTROLLER
PWM control circuit
source with soft start
Remark All the diodes in the figure are parasitic diodes.
ON / OFF
2 Seiko Instruments Inc.