SY21286ARHC

High Efficiency Fast Response, 98% Duty, 6A, 24V Input Synchronous Buck Converter

SY21286ARHC High Efficiency Fast Response, 98% Duty, 6A, 24V Input Synchronous Buck Converter Datasheet

Parameters
Features
Description

Part Number	SY21286ARHC
Vin_min (V)	4.5
Vin_max (V)	24
Vo_min (V)	0.6
Io_max (A)	6
Vref Accuracy	±1%
Fsw (MHz)	0.6
Iq (uA)	190
Package	QFN2.5×2.5-16
Protection Mode	Hic-cup Mode UVP
Features / Special Function	High Duty Cycle Capable using On-Time Stretch, PFM/FCCM Selectable Light Load Operation Mode, Power Good Indicator, Output Auto-Discharge Function

Low R_DS(ON) for Internal MOSFETs: 28mΩ Top, 16mΩ Bottom
Wide Input Voltage Range: 4.5V ~ 24V
Adjustable Output Voltage: 0.6V ~ 12.5V
High Duty Cycle Capable using On-Time Stretch
6A Continuous Output Current Capability
600kHz Pseudo-Constant Frequency
±1% Internal Reference Voltage
Internal 1.2ms Soft-Start Limits the Inrush Current
Constant On-Time and Ripple-Based Control to Achieve Fast Transient Responses
Integrated 1.2Ω Bypass Switch
PFM/FCCM Selectable Light Load Operation Mode
Power Good Indicator
Output Auto-Discharge Function
Adjustable Valley Current Limit Threshold by ILMT Pin
Cycle-by-Cycle Valley and Peak Current Limit Protection
Hic-Cup Mode Output Under Voltage Protection
Auto-Recovery Mode Output Over Voltage Protection
Auto-Recovery Mode Over Temperature Protection
Input Under Voltage Lockout (UVLO)
RoHS Compliant and Halogen Free
Compact Package: QFN2.5×2.5-16

The SY21286A is a high efficiency synchronous buck converter operating over a wide input voltage range of 4.5V to 24V and capable of delivering up to 6A current. It integrates low RDS(ON) top and bottom MOSFETs to minimize the conduction loss. It operates at a pseudoconstant frequency of 600kHz, to enable the use of small size inductor and capacitors. The SY21286A also provides a bypass switch which allows the VCC to be powered by external 3.3V power supply, further reduce the power consumption of the entire system.

Silergy’s constant on-time and ripple-based control strategy supports high input/output voltage ratios (low duty cycles), and fast transient response while maintaining a near constant operating frequency over line, load and output voltage ranges. This control method provides stable operation without complex compensation, including when using low ESR output ceramic capacitors.

The SY21286A provides cycle-by-cycle current limit, input under voltage lockout, internal soft-start, output under voltage protection, over voltage protection and over temperature protection, to guarantee safe operation in all operating conditions.