LT3587 TYPICAL PERFORMANCE CHARACTERISTICS Specifi cations are at TA = 25°C unless otherwise noted.EN/SS1, EN/SS3 ShutdownCAP3 Overvoltage ClampThreshold vs Temperaturevs Temperature 0.45 31 VVIN = 3.6V VVIN = 3.6V 0.40 TAGE (V) 30 TAGE (V) 0.35 29 0.30 28 0.25 CAP3 OV CLAMP VOL SHUTDOWN THRESHOLD VOL 0.20 27 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) 3587 G17 3587 G18 PIN FUNCTIONSVOUT3 (Pin 1): Boost3 Output Pin. This pin is the drain of FB2 (Pin 6): Inverter Output Voltage Feedback Pin. Con- an output disconnect PMOS transistor. nect a resistor RFB2 from this pin to the Inverter Output (V CAP3 (Pin 2): Boost3 Output Capacitor Pin. This pin is the NEG) such that: source of an output PMOS disconnect. Connect a capacitor RFB2 = |VNEG|/8μA from this pin to ground. Note that FB2 pin voltage is about 0V when in regulation. SW3 (Pin 3): Boost3 Switch Pin. Connect an inductor There is an internal 153k resistor from the FB2 pin to the from this pin to VIN. Minimize trace area at this pin to internal reference. minimize EMI. SW2 (Pin 9): Inverter Switch Pin. Connect an inductor GND (Pin 4, 7, 8, 12): Ground Pins. between this pin and VIN, as well as the fl ying capacitor FLT from this pin to the anode of the lnverter ground return (Pin 5): Fault Pin. This pin is a bidirectional open- diode. Minimize trace area at this pin to minimize EMI. drain pull-down pin. This pin pulls low when any of the enabled outputs fall out of regulation for more than 16ms. NC (Pin 10): No Connect Pin. Leave open or connect to Each output is ignored during start-up until its respective ground. enable/soft-start pin allows for full inductor current. This SW1 (Pin 11): Boost1 Switch Pin. Connect an inductor pin can also be externally forced low to disable all the from this pin to V supply outputs. Once this pin goes low (either due to an IN. Minimize trace area at this pin to minimize EMI. out of regulation condition or externally forced low), the pin latches low until the inputs to EN/SS1 and EN/SS3 are CAP1 (Pin 13): Boost1 Output Capacitor Pin. This pin set low or the input supply pin is recycled. Pull up this pin is the source of an output PMOS disconnect. Connect a to V capacitor from this pin to ground. IN with a 200k resistor when not used. 3587fc 6