DEMO C IR C U IT 1 4 4 9 Q U IC K S TA R T G U IDE U ltra lo w P o w e r B o o s t C o n v e rte r w ith Du a l H a lf-B rid g e S w itc h e s DESCRIPTION Demonstration circuit 1449A is an Ultralow Pow er Boost Converter w ith Dual Half-Bridge Sw itches featuring the LT8415. It converts a 3V-10V source to 16V supplying 1.6mA at 3Vin and 10mA at 10Vin. The 16V output is used to bias the DualHalf-Bridges w hich are activated by IN1 and IN2 and are pinned out at VOUT1 and VOUT2. IN1 controls VOUT1 w ith the same polarity and IN2 controls VOUT2. Each Half-Bridge drives a 200pF on-board capacitor. The LT8415 features a low noise control scheme, integrated pow er sw itch, dualhalf-bridge sw itches, schottky diode and output disconnect function, ultra-low quiescent current, built in soft-start and overvoltage protection. The LT8415 datasheet gives a complete description of the part, its operation and application information. The datasheet must be read in conjunction w ith this quick start guide for w orking on or modifying the demo circuit 1449. This circuit is intended for space-conscious applications such as Sensor Pow er, RF M ems, Low Pow er Actuator Bias/Control, Liquid Lens Drivers and General Purpose Bias Supplies. Design files for this circuit board are available. Call the LTC factory. L, LTC, LTM , LT are registered trademarks ofLinear Technology Corporation. PERF ORM ANCE SU M M ARY F OR DC1 3 8 7 A-A/L T8 4 1 0 SYM BOL VIN VOUT VOUT RIPPLE EFFICIENCY EFFICIENCY PARAM ETER Input Supply Range Output Voltage Range Output Voltage Range CONDITIONS VIN = 3V, ILOAD = 1.6mA VIN = 10V, ILOAD = 10mA VIN = 10V, ILOAD = 10mA VIN = 3V, ILOAD = 1.6mA VIN = 10V, ILOAD = 10mA Specifications are at TA = 25C M IN 3 15.54 15.54 TYP 16 16 20 73 83 M AX 10 16.48 16.48 UNITS V V V mV % % 1 Q U ICK START PROCEDU RE Demonstration circuit 1449 is easy to set up to evaluate the performance of the LT8415. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below : 1. Place jumpers in the follow ing positions: JP1 Run 2. W ith pow er off, connect the input pow er supply to Vin and G N D. 3. Turn on the pow er at the input. Check for the proper output voltages. Vout = 15.52V to 16.48V. NOTE. Ifthere is no output, temporarily disconnect the load to make sure that the load is not set too high. 4. O nce the proper output voltage is established, adjust the load w ithin the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. 5. To test the VO U T1 and VO U T2 outputs, apply a logic levelsquare w ave signal(typically 0V to 2V) at IN 1 and/or IN 2 and observe the amplitude levels and associated delays at VO U T1 and VO U T2. See datasheet for response driving externalcapacitors. Figure 1. Proper M easurem ent Equipm ent Setup 2 3