S-8550 Datasheet (Seiko Instruments) - (S-8550 / S-8551) PWM CONTROL SWITCHING REGULATORS

S-8550, (S-8550 / S-8551) PWM CONTROL SWITCHING REGULATORS

IC power supply pin GND pin Shutdown pin “H” : Power on (normal operation) “L” : Power off (standby) Output voltage feedback pin External inductor connection pin VIN VSS Pin No.

1 2 3 4 5 Symbol ON/OFF FB CONT 1 2 3 Figure 2 Table 2 Pin No.

1 2 3 4 5 S-8551 Series (Pin Configuration 2) Desc

Rev.2.1_01 www.DataSheet4U.com 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

S-8550 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%

* So