LTC3406 LTC3406-1.5/LTC3406-1.8 WUTYPICAL PERFOR A CE CHARACTERISTICS(From Figure 1a Except for the Resistive Divider Resistor Values)Start-Up from ShutdownLoad StepLoad Step VOUT RUN 100mV/DIV VOUT 2V/DIV AC COUPLED 100mV/DIV VOUT AC COUPLED 2V/DIV IL IL 500mA/DIV 500mA/DIV ILOAD 500mA/DIV ILOAD ILOAD 500mA/DIV 500mA/DIV V 40 3406 G16 V 20 3406 G17 V 20 3406 G18 IN = 3.6V µs/DIV IN = 3.6V µs/DIV IN = 3.6V µs/DIV V V V OUT = 1.8V OUT = 1.8V OUT = 1.8V I I I LOAD = 600mA LOAD = 0mA TO 600mA LOAD = 50mA TO 600mA Load StepLoad Step VOUT VOUT 100mV/DIV 100mV/DIV AC COUPLED AC COUPLED IL IL 500mA/DIV 500mA/DIV ILOAD ILOAD 500mA/DIV 500mA/DIV V 20 3406 G19 IN = 3.6V µs/DIV V 20 3406 G20 IN = 3.6V µs/DIV VOUT = 1.8V VOUT = 1.8V ILOAD = 100mA TO 600mA ILOAD = 200mA TO 600mA UUUPI FU CTIO SRUN (Pin 1): Run Control Input. Forcing this pin above VIN (Pin 4): Main Supply Pin. Must be closely decoupled 1.5V enables the part. Forcing this pin below 0.3V shuts to GND, Pin 2, with a 2.2µF or greater ceramic capacitor. down the device. In shutdown, all functions are disabled V drawing <1µA supply current. Do not leave RUN floating. FB (Pin 5) (LTC3406): Feedback Pin. Receives the feed- back voltage from an external resistive divider across the GND (Pin 2): Ground Pin. output. SW (Pin 3): Switch Node Connection to Inductor. This pin VOUT (Pin 5) (LTC3406-1.5/LTC3406-1.8): Output Volt- connects to the drains of the internal main and synchro- age Feedback Pin. An internal resistive divider divides the nous power MOSFET switches. output voltage down for comparison to the internal refer- ence voltage. 3406fa 5