Datasheet LT1952, LT1952-1 (Analog Devices) - 5

LT1952/LT1952-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). COMP = open, FB = 1.4V, ROSC = 178k, SYNC = 0V, SS_MAXDC = VREF, VREF = 0.1µF, SD_VSEC = 2V, BLANK = 121k, DELAY = 121k, ISENSE = 0V, OC = 0V, OUT = 1nF, VIN = 15V, SOUT = open, unless otherwise specified. PARAMETER CONDITIONS MIN TYP MAX UNITS SOFT-START
SS_MAXDC Low Level: VOL I(SS_MAXDC) = 150µA, OC = 1V 0.2 V SS_MAXDC Soft-Start Reset Threshold Measured on SS_MAXDC 0.45 V SS_MAXDC Active Threshold FB = 1V, DC > 0% 0.8 V SS_MAXDC Input Current (Soft-Start Pull-Down: Idis) SS_MAXDC = 1V, SD_VSEC = 1.4V, OC = 1V 800 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Rise and Fall times are measured at 10% and 90% levels. may cause permanent damage to the device. Exposure to any Absolute
Note 4:
Guaranteed by correlation to static test. Maximum Rating condition for extended periods may affect device
Note 5:
Each IC includes over-temperature protection that is intended reliability and lifetime. to protect the device during momentary overload conditions. Junction
Note 2:
The LT1952/LT1952-1 are tested under pulsed load conditions temperature will exceed 125°C when over-temperature protection is active. such that TJ ≈ TA. The LT1952EGN/LT1952EGN-1 are guaranteed to meet Continuous operation above the specified maximum operating junction performance specifications from 0°C to 125°C junction temperature. temperature may impair device reliability. Specifications over the –40°C to 125°C operating junction temperature
Note 6:
Guaranteed but not tested. range are assured by design, characterization and correlation with statistical process controls. The LT1952IGN/LT1952IGN-1 are guaranteed
Note 7:
Maximum recommended SYNC frequency = 500kHz. over the –40°C to 125°C operating junction temperature range and the
Note 8:
In applications where the VIN pin is supplied via an external RC LT1952MPGN/LT1952MPGN-1 are tested and guaranteed over the full network from a SYSTEM VIN > 25V, an external zener with clamp voltage –55°C to 125°C operating junction temperature range. Note that the VIN ON(MAX) < VZ < 25V should be connected from the VIN pin to ground. maximum ambient temperature consistent with these specifications is
Note 9:
VIN start-up current is measured at VIN = VIN ON – 0.25V and determined by specific operating conditions in conjunction with board scaled by x 1.18 (to correlate to worst case VIN start-up current at VIN ON). layout, the rated package thermal impedance and other environmental
Note 10:
Timing for R = 40k derived from measurement with R = 240k. factors. 19521fe 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Timing Diagram Block Diagram Operation Applications Information Typical Applications Revision History Package Description Related Parts