Buck Regulator Delivers Small Size, High Efficiency

Jun 11, 2008 10:45 PM

The S-8550/8551 from Seiko Instruments are fully integrated, 600-mA synchronous buck regulators that enable both high efficiency and small size. These regulators come in SOT-23-5 packages with a choice of pin outs and operate at a 1.2-MHz switching frequency that permit use of small external components.

Device type: synchronous buck regulator
Input voltage range: 2.0 to 5.5 V
Output voltage: resistor adjustable 1.1 V to 4.0 V
Output current: 600 mA
Quiescent Current: 400 µA max , 1.0 µA max. in shutdown
Efficiency: 92 % (see data sheet for more on efficiency), on resistance is 0.4 Ω typ. for p-channel MOSFET and 0.3 Ω typ. for n-channel MOSFET
Features: voltage reference, oscillator, error amplifier, phase-compensation circuit, PWM controller, power MOSFETs, constant continuous-mode operation (no light-load mode), undervoltage lockout circuit, current limit circuit, soft-start, and choice of two pinouts
Operating temperature range: -40°C to +85°C
Packaging: SOT-23-5
RoHS compliant? yes
Target applications: mobile devices, such as mobile phones, Bluetooth devices, wireless devices, digital audio players, digital still cameras, portable DVD players, and portable CD players
Pricing: $0.54 each in quantities of 10,000
Availability: available now

Data sheet posted on web? yes, see http://dl.sii-ic.com.edgesuite.net/spd_dtst/dt_sht_e/swi_regu/S8550_8551_E.pdf