Datasheet LTC3121 (Analog Devices) - 6

LTC3121
Typical perForMance characTerisTics Efficiency vs Frequency CAP Pin Voltage vs VOUT VCC vs VIN
100 0 4.5 90 –1 80 (V) 4.0 70 –2 OUT 60 –3 50 (V) 3.5 –4 V CC 40 EFFICIENCY (%) 30 , REFERRED TO V –5 3.0 20 f V CAP OSC = 200kHz –6 10 fOSC = 1MHz VIN FALLING fOSC = 3MHz VIN RISING 0 –7 2.5 10 100 1000 0 2 4 6 8 10 12 14 0 1 2 3 4 5 6 OUTPUT CURRENT (mA) VOUT (V) VIN (V) 3121 G19 3121 G20 3121 G21
Burst Mode Operation PWM Mode to Burst Mode Burst Mode Operation to PWM Mode Operation
VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC-COUPLED AC-COUPLED AC-COUPLED VSW 10V/DIV VPWM/SYNC 2V/DIV INDUCTOR VPWM/SYNC CURRENT 2V/DIV 0.5A/DIV OUTPUT CURRENT = 50mA OUTPUT CURRENT = 70mA OUTPUT CURRENT = 70mA 5µs/DIV 3121 G22 20µs/DIV 3121 G23 20µs/DIV 3121 G24
Burst Mode Transient Synchronized Operation Short-Circuit Response
SHORT-CIRCUIT APPLIED ILOAD = 100mA V VOUT OUT 200mV/DIV 5V/DIV AC-COUPLED V SHORT-CIRCUIT SW 5V/DIV REMOVED 100mA OUTPUT SYNCHRONIZED TO 1.3MHz CURRENT V INDUCTOR PWM/SYNC 100mA/DIV 10mA 10mA 5V/DIV CURRENT 1A/DIV 200µs/DIV 3121 G25 1µs/DIV 3121 G26 200µs/DIV 3121 G27 3121fa 6 For more information www.linear.com/LTC3121 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Low Voltage Operation Low Noise Fixed Frequency Operation Burst Mode Operation Applications Information PCB Layout Guidelines Schottky Diode Component Selection Operating Frequency Selection Typical Applications Package Description Revision History Typical Application Related Parts