Datasheet LTC3100 (Analog Devices) - 17

LTC3100
APPLICATIONS INFORMATION PC Board Layout Guidelines
pins should be placed as close to the IC as possible The LTC3100 switches large currents at high frequen- and should have the shortest possible paths to ground. cies. Special care should be given to the PC board layout 2. To prevent large circulating currents from disrupting the to ensure stable, noise-free operation. You will not get output voltage sensing, the ground for each resistor advertised performance with a careless layout. Figure 1 divider should be returned directly to the ground plane depicts the recommended PC board layout. A large ground near the IC. pin copper area will help to lower the chip temperature. 3. Use of vias in the die attach pad of the IC will enhance A multilayer board with a separate ground plane is ideal, the thermal environment of the converter, especially if but not absolutely necessary. the vias extend to a ground plane region on the exposed A few key guidelines follow: bottom surface of the PC board. 1. All circulating high current paths should be kept as 4. Keep the connection from the resistor dividers to the short as possible. Capacitor ground connections should feedback pins as short as possible and away from the via down to the ground plane in the shortest route switch pin connections. possible. The bypass capacitors on all VIN and VOUT V INBST PGBST RUNBST MODE 16 15 14 13 SWBST 1 LTC3100 12 FBBST VBST 2 11 FBLDO V RUNLDO LDO 3 10 SWBK 4 9 FBBK 5 6 7 8 V INBK PGBK GND RUNBK VBUCK 3100 F01
Figure 1. Recommended Component Placement for Two-Layer PC Board
3100fb For more information www.linear.com/LTC3100 17 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts