A4402: Constant On-Time Buck Converter with Integrated Linear Regulator - ALLEGRO MICROSYSTEMS - #1

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Description The A4402 is a power management IC that combines a 2% constant on-time buck regulator and a 2% linear regulator. Ideal for applications that require two regulated voltages. The buck regulator output supplies the adjustable linear regulator to reduce power dissipation and increase overall efficiency. The switching regulator is capable of operating above 2 MHz. A greater than 2 MHz switching frequency enables the customer to select low value inductors and capacitors while avoiding EMI. Protection features include undervoltage lockout and thermal shutdown. In case of a shorted load, each regulator features overcurrent protection. The A4402 also features a power-on reset with adjustable delay for the microprocessor output. The A4402 is provided in a 16-pin, 1.20 mm nominal overall height TSSOP, with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating. 4402-DS, Rev. 2 Features and Benefits 2 MHz switching frequency Adjustable soft start timer Watchdog input Power-on reset output Adjustable 2% buck regulator Adjustable 2% linear regulator Enable input 6 to 50 V supply voltage range Overcurrent protection Undervoltage lockout (UVLO) Thermal shutdown protection Constant On-Time Buck Converter with Integrated Linear Regulator Package: 16-pin TSSOP with exposed thermal pad (suffix LP) Typical Application Not to scale A4402 ENB VO2 NPOR GND GND GND 1 ìF 3.3 V 300 mA VO2 L1 33 ìH VIN1 LX FB1 10 ìF VBAT FB2 VIN2 POR CPOR TSET CTSET 5 V 0.1 ìF ISEN VLIN VSW Switching Regulator Output Linear Regulator Output A4402 TON 0.01 ìF RSENSE 4.7 ìF 20 Rton 750 kÙ kÙ kÙ WDI 0.33 ìF 0.15 ìF kÙ R1 31.6 kÙ R2 9.76 R3 10 R4 5.62 kÙ 4.7 kÙ BOOT Photo and inkjet printers Industrial controls Distributed power systems Network applications Applications: