Datasheet LTC1875 (Analog Devices) - 4

LTC1875
W U TYPICAL PERFOR A CE CHARACTERISTICS Reference Voltage vs Output Voltage vs Load Current Temperature
1.84 805 VIN = 6V 804 1.82 803 1.80 802 801 1.78 800 1.76 799 OUTPUT VOLTAGE (V) 1.74 798 REFERENCE VOLTAGE (mV) 797 Burst Mode OPERATION 1.72 VIN = 3.6V 796 L = 4.7µH 1.70 795 0 500 1000 1500 2000 –50 –25 0 25 50 75 100 125 LOAD CURRENT (mA) TEMPERATURE (°C) 1875 G07 1875 G13
Efficiency vs Output Current Efficiency vs Output Current
95 100 V V IN = 4.2V V 90 IN = 3V 90 IN = 3.6V 85 80 70 80 V V IN = 3.6V IN = 4.2V 60 75 VIN = 3.6V VIN = 6V 50 70 VIN = 4.2V 40 EFFICIENCY (%) 65 EFFICIENCY (%) 30 60 20 VOUT = 1.8V VOUT = 1.8V L = 4.7µH 55 L = 4.7µH 10 Burst Mode OPERATION Burst Mode OPERATION PULSE SKIPPING MODE 50 0 0.1 1 10 100 1000 0.1 1 10 100 1000 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 1875 G14 1875 G15
Efficiency vs Input Voltage Load Step (Burst Mode Operation)
100 100mA 10mA 95 VOUT 100mV/DIV 90 1mA 85 IL 80 1A/DIV 75 70 0.1mA ITH EFFICIENCY (%) 1V/DIV 65 60 VOUT = 2.5V 50µs/DIV 1875 G08 55 L = 6.8µH VIN = 3.6V CIN = 22µF Burst Mode OPERATION VOUT = 1.5V COUT = 47µF 50 2 3 4 5 6 L = 6.8µH ILOAD = 200mA to 1700mA INPUT VOLTAGE (V) 1875 G16 1875f 4