S-8550 Series
STEP-DOWN, BUILT-IN FET, SYNCHRONOUS
RECTIFICATION, PWM CONTROL SWITCHING REGULATORS
www.sii-ic.com
© SII Semiconductor Corporation, 2007-2015
Rev.5.0_01
The S-8550 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 packages small SOT-23-5 and super-small and thin SNT-8A.
Features
• Oscillation frequency:
• Input voltage range:
• Output voltage range:
• Output current:
1.2 MHz
2.0 V to 5.5 V
Arbitrarily settable by external output voltage setting resistor
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:
• Nch power MOS FET on-resistance:
0.4 Ω typ.
0.3 Ω typ.
• Constant continuous mode operation (no light load mode)
• Lead-free, Sn 100%, halogen-free*1
*1. Refer to “ Product Name Structure” for details.
Applications
•
Mobile devices, such as mobile phones, Bluetooth devices, wireless devices, digital audio players, digital still
cameras, portable DVD players, and portable CD players
Packages
•
•
SOT-23-5
SNT-8A
1