LTC3104 BLOCK DIAGRAM C2 VIN VCC VCC PRE-REG VCC BST C3 IBIAS VCC BOOST UVLO OSC IPEAK(REF) – C I BST 0.6V 0.8V I PEAK PEAK COMP UVLO + R6 VREF V TOP_ON REF_GOOD RUN + L1 SHUTDOWN CONTROL ANTICROSS SW VOUT R5 SD LOGIC LOGIC BOT_ON CONDUCT BURST ENABLE C1 0.8V – + IZERO MODE TSD COMP THERMAL – SHUTDOWN SHUTDOWN UVLO TSD + + RUNLDO RUNLDO PWM PWM LOGIC LDOENABLE COMP SLOPE COMP – + 0.6V gm + SS R2 – FB + SLEEP R1 COMP – SLEEP REF PGOOD – 0.6V – 10% + VINLDO VCC LDO LDOENABLE VLDO VLDO R4 C5 FBLDO 0.6V GND R3 3104 BD OPERATION The LTC3104 step-down DC/DC converter is capable of ratios without pulse skipping. With the automatic Burst supplying 300mA to the load. The output voltage is adjust- Mode feature and the LDO enabled, the typical DC supply able over a broad range and can be set as low as 0.6V. current drops to only 2.6µA with no load. The LTC3104 Both the power and the synchronous rectifier switches also includes an independent, 10mA LDO regulator with are internal N-channel MOSFETs. The converter uses a a VIN range of 2.5V to 15V. constant-frequency, current mode architecture and may be configured using automatic Burst Mode operation for Main Control Loop highly efficient light load operation or for low noise forced During normal operation, the internal top power MOSFET continuous conduction operation where the converter is is turned on at the beginning of each cycle and turned optimized to operate over a broad range of step-down off when the PWM current comparator trips. The peak 3104fa For more information www.linear.com/LTC3104 9 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
