? GENERAL DESCRIPTION

AX3111A

consists of step down switching regulator with PW M control. These devise include a reference voltage source, oscillation circuit, error amplifier, internal PMOS and etc.

AX3111A provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to the duty ratio linearly form 0 up to 100%. This converter is build out soft start function that prevents overshoot and inrush current at startup. An ov er current protect function and short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced. The operating frequency is decided by outside resistance An external compensation is easily to system st able; the low ESR output capacitor can be used.

With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SOP-8L packages, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage up to 40V, it is also suitable for the operation via an AC adapter.

? FEATURES

- Input voltage 8V to 40V

- Output voltage VFB to 38V

- Duty ratio 0% to 100% PWM control

- Oscillation frequency range is 50K 350KHz by outside resistance setting

- Enable with Soft Start function

- Current Limit Short Circuit Protect (SCP) and Thermal Shutdown protection

- Built-in internal SW P-channel MOS.

- SOP-8L-EP Pb-Free packages.

- RoHS and Halogen free compliance.