AN-SY8105 - Silergy

AN-SY8105 Synchronous Step Down Regulator

The SY8105 is a high efficiency 500 kHz synchronous step-down DC-DC converter capable of delivering 5.0A current. The SY8105 operates over a wide input voltage range from 4.5V to 18V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss. Low output voltage ripple and small external inductor and capacitor si.

Features

• low RDS(ON) for internal switches (top/bottom): 40mΩ/26mΩ
• 4.5-18V input voltage range
• 5.0A output current capability
• 500 kHz switching frequency
• Instant PWM architecture to achieve fast transient responses.
• Internal softstart limits the inrush current
• Cycle-by-cycle peak current limitation
• 1.5% 0.6V reference
• TSOT23-6 package Applications
• Set Top Box
• Portable TV
• Access Point Router
• DSL Modem
• LCD TV Typical Applications Figure 1. Schematic Diagram Efficiency (%) 100 90 80 70 60 50 40 30 20 10 0 0.001 Efficiency vs. Load Current VIN=5V,VOUT=3.3V VIN=12V,VOUT=3.3V.