Datasheet LT1952, LT1952-1 (Analog Devices) - 3

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 PWM CONTROLLER
Operational Input Voltage I(VREF) = 0µA l VIN OFF 25 V VIN Quiescent Current I(VREF) = 0µA, ISENSE = OC = Open 5.2 6.5 mA VIN Start-up Current (LT1952) FB = 0V, SS_MAXDC = 0V (Notes 4, 9) l 460 700 µA VIN Start-up Current (LT1952-1) FB = 0V, SS_MAXDC = 0V (Notes 4, 9) l 400 575 µA VIN Shutdown Current SD_VSEC = 0V 240 350 µA SD_VSEC Threshold 10V < VIN < 25V l 1.261 1.32 1.379 V SD_VSEC (ON) Current SD_VSEC = SD_VSEC Threshold + 100mV 0 µA SD_VSEC (OFF) Current SD_VSEC = SD_VSEC Threshold – 100mV 8.3 10 11.7 µA VIN ON (LT1952) l 14.25 15.75 V VIN OFF (LT1952) l 8.75 9.25 V VIN HYSTERESIS (LT1952) l 3.75 5.5 6.75 V VIN ON (LT1952-1) E-, I-Grades l 7.75 8.13 V MP-Grade l 7.75 8.3 V VIN OFF (LT1952-1) l 6.5 6.82 V VIN HYSTERESIS (LT1952-1) l 0.95 1.25 V
VREF
Output Voltage I(VREF) = 0µA l 2.425 2.5 2.575 V Line Regulation I(VREF) = 0µA, 10V < VIN < 25V 1 10 mV Load Regulation 0µA < I(VREF) < 2.5mA 1 10 mV
OSCILLATOR
Frequency: fOSC ROSC = 178k, FB = 1V, SS_MAXDC = 1.84V l 165 200 240 kHz Minimum Programmable fOSC ROSC = 365k, FB = 1V 80 100 120 kHz Maximum Programmable fOSC ROSC = 64.9k, COMP = 2.5V, SD_VSEC = 2.64V 440 500 560 kHz SYNC Input Resistance 18 kΩ SYNC Switching Threshold FB = 1V 1.5 2.2 V SYNC Frequency/fOSC FB = 1V (Note 7) 1.25 1.5 fOSC Line Reg FB = 1V, ROSC = 178k; 10V < VIN < 25V, 0.05 0.33 %/V SS_MAXDC = 1.84V VROSC ROSC Pin voltage 1 V
ERROR AMPLIFIER
FB Reference Voltage 10V < VIN < 25V, VOL + 0.2V < COMP < VOH – 0.2 l 1.201 1.226 1.250 V FB Input Bias Current FB = FB Reference Voltage –75 –200 nA Open Loop Voltage Gain VOL + 0.2V < COMP < VOH – 0.2 65 85 dB Unity Gain Bandwidth (Note 6) 3 MHz COMP Source Current FB = 1V, COMP = 1.6V –4 –9 mA COMP Sink Current COMP = 1.6V 4 10 mA COMP Current (Disabled) FB = VREF, COMP = 1.6V 18 23 28 µA COMP High Level: VOH FB = 1V, I(COMP) = –250µA 2.7 3.2 V COMP Active Threshold FB = 1V, SOUT Duty Cycle > 0 % 0.7 0.8 V 19521fe 3 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