? GENERAL DESCRIPTION

AX3703A can operate with input voltage from 2.5V to 5.5V and provide output range from 0.6V to input level, thanks to its 100% duty cycle operation. AX3703A is a 1.5MHz, 2.5A/3A constant on-time (COT) controlled synchronous step-down converter.

AX3703A consumes extremely low 15μA quiescent current hence achieves superior light load efficiency. The constant on-time control scheme simplifies loop compensation and offers excellent load transient response.

AX3703A has cycle-by-cycle current limit and hiccup mode to protect over-load or short circuit fault conditions. The high gain error amplifier in the control loop provides excellent load and line regulation. Proprietary adaptive on-time helps AX3703A to achieve nearly constant switching frequency across load range.

AX3703A is available in low profile SOT23-5L, SOT23-6L and 8 leads DFN 2mm x 2mm packages.

? FEATURES

- AX3703A Z8A : Built in 90m?/60m? Power Switches

- AX3703AZ8A: 3A Continuous Output Current

- AX3703A CA : 2.5A Continuous Output Current , 3A Peak Output Current

- AX3703A CA : Built in 94m?/76m? Power Switches

- Wide Input Range from 2.5V to 6V

- Proprietary Fast Transient Constan t On Time Architecture Stable with low ESR Ceramic Output Capacitors

- 1.5MHz Switching Frequency

- 15μA Low Quiescent Current

- +/-2% 0.6V Feedback Voltage

- 1.21V Accurate Enable Threshold

- Up to 95% Efficiency

- 100% Duty Cycle Operation

- Thermal Shutdown Protec tion

- Internal 1msec Soft-Start

- Cycle-by-cycle Current Limit Protection

- Over-Load and Short Circuit Hiccup Mode

- Open Drain Power Good Indication

- Output Discharge

- Available in Small SOT23_5L, SOT23_6L and DFN2x2_8L

- Pb-Free RoHS Compliant

- RoHS and Halogen free compliance.

? APPLICATION

- WiFi RF Moudules

- Smart Phone and Tablets

- Solid-State and Hard Disk Drives

- DC/DC Micro Modules