Datasheet Summary
SY81103, SY81103E, SY81103C, SY81103B
High Efficiency, 3A, 18V Input Synchronous Buck Converter
General Description
The SY81103x is high efficiency synchronous buck converter operates over a wide input voltage range of 4.5V to 18V, and can deliver an output current up to 3A. It integrates a top MOSFET and a bottom MOSFET with very low RDS(ON) to minimize conduction loss. The 500kHz or 1200kHz high pseudo-constant switching frequency enables using small external inductor and capacitor values.
The device uses constant on-time and ripple-based control strategy to achieve fast transient response for applications with high step-down ratios, and high efficiency at light loads. It also provides cycle-by-cycle current limit protection, output under voltage protection and over temperature protection.
Only the input and output capacitors, inductor, feedback resistor divider and feedforward capacitor need to be selected for the targeted application specifications.
The SY81103x is available in a pact SOT23-6 package.
Part Number SY81103ABT SY81103EABT SY81103CABT SY81103BABT
Frequency 500kHz 500kHz 1200kHz 1200kHz
Mode PFM FCCM PFM FCCM
Features
- Low RDS(ON) for Internal MOSFETs: 80mΩ Top, 40mΩ Bottom
- Wide Input Voltage Range: 4.5V ~ 18V
- Up to 3A Output Current
- ±1.5% 0.6V Reference
- Precise EN Threshold
- Pulse-Frequency Modulation (PFM) Mode
Operation for SY81103 and SY81103C
- Forced Continuous Conduction Mode (FCCM)
Operation for SY81103E and SY81103B
- Internal Soft-Start Limits the Inrush Current
- Support Smooth Startup with Pre-Biased Output
- 500kHz Switching Frequency Minimizes the
External ponents for SY81103 and SY81103E
- 1200kHz Switching Frequency Minimizes the
External ponents for SY81103C and SY81103B
- Constant On-time and Ripple-Based...