AX3803 Datasheet | AXElite

AX3803 3A, 23V, 500KHz Synchronous Rectified Step-Down Converter  GENERAL DESCRIPTION The AX3803 is a monolithic synchronous buck regulator. The device integrates two 110mΩ MOSFETs, and provides 3A of continuous load current over a wide input voltage of 4.75V to 23V. Current mode control provides fast transient response and cycle-by-Cycle current limit. Internal soft-start prevents inrush current at turn-on, and in shutdown mode the supply current drops to 5μA. This device, available in SOP-8L-EP package, provides a very pact solution with minimal external ponents.  Features 3A Output Current Wide 4.75V to 23V Operating Input Range Integrated 110mΩ Power MOSFET Switches Output adjust from VFB to 20V Internal pensation Up to 94% Efficiency Stable with Low ESR Ceramic Output Capacitors Fixed 500KHz Frequency Cycle-by-Cycle Over Current Protection Thermal shutdown and short circuit protections  BLOCK DIAGRAM CURRENT SENSE AMPLIFIER OSCILLATOR FB 5 140/500KHz 1 BS RAMP CLK 2 IN + 5V  + NC 8 0.925V M1 110mΩ + + ERROR AMPLIFIER 6μA - CURRENT PARATOR M2 110mΩ 3 SW 4 GND NC 6 IN EN 7 + 1.5V INTERNAL REGULATORS SHUTDOWN PARATOR 5V - 1/8 Axelite Confidential Materials, do not copy or distribute without written consent. Rev.1.0 Nov.22, 2012  PIN ASSIGNMENT The package of AX3803 is SOP-8L-EP; the pin assignment is given by: Name Description High-Side Gate Drive Boost Input. BS supplies the drive for the high-side BS N-Channel MOSFET switch. Connect a 0.01μF or greater capacitor from SW to BS to power the high side switch. Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a IN 4.75V to 23V power source. Bypass IN to GND with a suitably large capacitor ( Top View ) to eliminate noise on the input to the IC. See Input Capacitor. BS 1 8 NC Power Switching Output. SW is the switching node that supplies power to Exposed 7 EN IN 2 the output. Connect the output LC filter...