S-8550 Datasheet, PDF (1/26 Pages) Seiko Instruments Inc – STEP-DOWN, BUILT-IN FET, SYNCHRONOUS RECIFICATION, PWM CONTROL SWITCHING REGULATORS

Rev.2.1_01
STEP-DOWN, BUILT-IN FET, SYNCHRONOUS
RECTIFICATION, PWM CONTROL SWITCHING REGULATORS
S-8550/8551 Series
The S-8550/8551 Series is a CMOS synchronous rectification step-down
switching regulator which mainly consists of a reference voltage circuit, an
oscillator, an error amplifier, a phase compensation circuit, a PWM controller, an
under voltage lockout circuit (UVLO), a current limit circuit, and a power MOS
FET. The oscillation frequency is high at 1.2 MHz, so a high efficiency, large
output current, step-down switching regulator can be achieved by using small
external parts.
The built-in synchronous rectification circuit makes achieving high efficiency
easier compared with conventional step-down switching regulators. A ceramic
capacitor can be used as an output capacitor. High-density mounting is
supported by adopting a small SOT-23-5 package.
The S-8550 and S-8551 Series are offered according to different pin configuration.
„ Features
• Oscillation frequency :
1.2 MHz
• Input voltage range :
2.0 to 5.5 V
• Output voltage range :
Arbitrarily settable by external output voltage setting resistor
• Output current :
600 mA
• Reference voltage :
0.6 V ±2.0%
• Efficiency :
92%
• Soft-start function :
1 ms typ.
• Shutdown function :
Shutdown current consumption : 1.0 µA max.
• Built-in current limit circuit
• Pch power MOS FET on-resistance :
0.4 Ω typ.
• Nch power MOS FET on-resistance :
0.3 Ω typ.
• Constant continuous mode operation (no light load mode)
• Small package :
SOT-23-5
• Lead-free products
„ Applications
• Mobile devices, such as mobile phones, Bluetooth devices, wireless devices, digital audio players, digital still
cameras, portable DVD players, and portable CD players
„ Package
Package Name
SOT-23-5
Package
MP005-A
Drawing Code
Tape
MP005-A
Reel
MP005-A
Seiko Instruments Inc.
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