Datasheet LTC1771 (Analog Devices) - 3

LTC1771
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25
°
C. VIN = 10V, VRUN = open unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VRUN/SS RUN/SS Pin Threshold VRUN/SS Rising ● 0.5 1.0 2 V IRUN Source Current VRUN = 0V, VIN = 2.8V to 18V 0.3 1 3 µA PGATE tr, tf PGATE Transition Time (Note 7) Rise Time CLOAD = 2000pF 70 140 ns Fall Time CLOAD = 2000pF 70 140 ns
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Dynamic supply current is higher due to the gate charge being of a device may be impaired. delivered at the switching frequency. See Applications Information.
Note 2:
TJ is calculated from the ambient temperature TA and power
Note 5:
The LTC1771 is tested in a feedback loop that servos VFB to the dissipation PD according to the following formulas: balance point for the error amplifier (VITH = 1.23V). LTC1771S8: TJ = TA + (PD)(110°C/W)
Note 6:
No-load supply current consists of sleep mode current (9µA LTC1771MS8: T typical) plus a small switching component necessary to overcome J = TA + (PD)(150°C/W)
Note 3:
The LTC1771E is guaranteed to meet performance specifications Schottky diode leakage and feedback resistor current. from 0°C to 70°C. Specifications over the – 40°C to 85°C operating
Note 7:
tr and tf are measured at 10% to 90% levels. temperature range are assured by design, characterization and correlation with statistical process controls. The LTC1771I is guaranteed and tested over the – 40°C to 85°C operating temperature range.
W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs Input Voltage Efficiency vs Load Current Line Regulation
100 100 0.4 FIGURE 1 CIRCUIT Burst Mode OPERATION FIGURE 1 CIRCUIT 90 ENABLED 0.3 80 90 0.2 ILOAD = 1A 70 (%) 60 0.1 ILOAD = 100mA ILOAD = 50mA Burst Mode OPERATION (%) 80 50 DISABLED 0 OUT 40 ∆V I – 0.1 EFFICIENCY (%) LOAD = 1mA EFFICIENCY 30 ILOAD = 1A 70 – 0.2 20 10 V – 0.3 IN = 10V FIGURE 1 CIRCUIT 60 0 – 0.4 2 4 6 8 10 12 14 16 18 20 0.1 1 10 100 1000 0 5 10 15 20 INPUT VOLTAGE (V) LOAD CURRENT (mA) INPUT VOLTAGE (V) 1771 G02 1771 G01 1771 G03 3