Datasheet LTC3122 (Analog Devices) - 6

LTC3122
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) 3122 G19 3122 G20 3122 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 3122 G22 20µs/DIV 3122 G23 20µs/DIV 3122 G24
Burst Mode Transient Synchronized Operation Short-Circuit Response
SHORT-CIRCUIT APPLIED VOUT VOUT 5V/DIV 200mV/DIV AC-COUPLED VSW 5V/DIV SHORT-CIRCUIT REMOVED 100mA OUTPUT SYNCHRONIZED TO 1.3MHz CURRENT V INPUT PWM/SYNC 100mA/DIV 10mA 10mA 5V/DIV CURRENT 2A/DIV 200µs/DIV 3122 G25 1µs/DIV 3122 G26 100µs/DIV 3122 G27 3122fa 6 For more information www.linear.com/LTC3122 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts