LTC3603 typical perForMance characteristics5V LDO Output VoltageTRACK/SS CurrentLoad Regulationvs Temperaturevs Temperature 0.10 5.10 1.40 FIGURE 6 CIRCUIT V 5.08 IN = 12V 5.06 1.35 5.04 0 1.30 (%) 5.02 OUT/V 5.00 1.25 4.98 ∆V OUT –0.10 4.96 1.20 LDO OUTPUT VOLTAGE (V) TRACK/SS CURRENT (µA) 4.94 1.15 4.92 –0.20 4.90 1.10 0 0.5 1 1.5 2 2.5 3 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 LOAD CURRENT (A) TEMPERATURE (°C) TEMPERATURE (°C) 3603 G18 3603 G19 3603 G20 pin Functions MSE/UF Package INTVCC (Pin 1/Pin 3): Output of Internal 5V LDO. TRACK/SS (Pin 9/Pin 11): Tracking Input for the Controller SYNC/MODE (Pin 2/Pin 4): Mode Select and External Clock or Optional External Soft-Start Input. This pin allows the Synchronization Input. Do not leave this pin floating. start-up of VOUT to “track” the external voltage at this pin using an external resistor divider. An external soft-start can PGOOD (Pin 3/Pin 5): Power Good Output. Open-drain be programmed by connecting a capacitor between this logic output that is pulled to ground when the output volt- pin and ground. Leave this pin floating to use the internal age is not within ±10% of regulation point. 1ms soft-start clamp. Do not tie this pin to INTVCC or to RT (Pin 4/Pin 6): Frequency Set Pin. PVIN. ITH (Pin 5/Pin 7): Error Amplifier Compensation Point. PGND (Pins 10, 11/Pins 12, 13, 14, 15): Power Ground. VFB (Pin 6/Pin 8): Feedback Pin. SW (Pins 12, 13/Pins 16, 17, 18, 19): Switch Node Con- SGND (Pin 7, Exposed Pad Pin 17/Pin 9, Exposed Pad nection to the Inductor. Pin 21): Signal Ground. Exposed pad is signal ground and must be soldered to the PCB for rated thermal BOOST (Pin 14/Pin 20): Bootstrapped Supply to the Top performance. Side Floating Gate Driver. RUN (Pin 8/Pin 10): Run Control Input. This pin may be tied PVIN (Pins 15, 16/Pins 1,2): Power Input Supply. Decouple to PV this pin with a capacitor to PGND IN to enable the chip. Do not leave this pin floating. 3603fc 6 For more information www.linear.com/LTC3603