MODE Datasheet AS1328 3A, 1.5MHz Synchronous DC/DC Step-Down Converter 1 General description 2 Key features High Efficiency: up to 96% The AS1328 is a high-efficiency, synchronous buck converter that can deliver up to 3A. The device is available in adjustable- and fixed- Input Voltage Range: 2.7V to 5.5V output voltage versions. The wide input voltage range (2.7V to 5.5V), automatic Powersave Mode and minimal external component Output Voltage Range (factory set): 0.7V to 4.8V requirements make the AS1328 perfect for any single Li-Ion battery- User-Adjustable Output Voltage Range: 0.6V to VIN powered application. Output Current: 3A Typical quiescent current with no load is 25 A and decreases to 1 A in shutdown mode. The highly efficient duty cycle (100%) pro- Low battery detection or Power Okay function vides low dropout operation, prolonging battery life in portable sys- tems. Constant Frequency Operation (1.5MHz) or Powersave Opera- tion The AS1328 is available with user adjustable output voltage between 0.6V and VIN via an external resistor divider. Softstart Function The switching frequency (1.5MHz) allows the use of a small surface No Schottky diode required mount inductor. Automatic Powersave Operation A user adjustable Softstart function limits the input current during start-up. Low Dropout Operation: 100% Duty Cycle The AS1328 is available in a TQFN (3x3mm) 16-pin package. 215ms POK timeout (optional) AS1328 offers several power monitoring functions. Low Quiescent Supply Current: 25 A Part Name Description Shutdown Current: 1 A AS1328A Power-Okay Function Thermal protection AS1328B Low Battery Detection AS1328C Power-Okay Function with 215ms delay TQFN (3x3mm) 16-pin Package. 3 Applications The device is ideal for mobile communication devices, laptops and PDAs, SSD, point of load supply of P and FPGA based systems, medical instruments or any other application with high current requirements. Figure 1. AS1328 - Typical application diagram 2.2 H VIN VOUT 2.7V to 5.5V VIN COUT 0.7V to 4.8V, 3A SW CIN 44 F 44 F SRC PGND AS1328A GND EN FB POK RSI GND www.ams.com/DC-DC Step-Down/AS1328 Revision 1.04 1 - 30AS1328 Datasheet - Pin assignment 4 Pin assignment Figure 2. Pin assignment (top view) of the two versions AS1328A (POK function) and AS1328B (LBI function) 1 12 1 12 PVDD GND PVDD GND 2 11 2 11 SW EN SW EN AS1328A AS1328B SW 3 10 POK SW 3 10 LBO 4 9 4 9 PGND RSI PGND LBI Exposed Pad Exposed Pad www.ams.com/DC-DC Step-Down/AS1328 Revision 1.04 2 - 30 5 16 PGND PVDD 6 15 GND VDD 7 14 GND FB 8 13 MODE SRC 5 16 PGND PVDD 6 15 GND VDD 7 14 GND FB 8 13 MODE SRC