Datasheet LTC1871-1 (Analog Devices) - 3

LTC1871-1
ELECTRICAL CHARACTERISTICS The
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denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 5V, VRUN = 1.5V, RFREQ = 80k, VMODE/SYNC = 0V, unless otherwise specifi ed. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V + RUN Rising RUN Input Threshold Voltage 1.348 V V – RUN Falling RUN Input Threshold Voltage 1.223 1.248 1.273 V ● 1.198 1.298 V VRUN(HYST) RUN Pin Input Threshold Hysteresis 50 100 150 mV I-Grade (Note 2) ● 35 100 175 mV IRUN RUN Input Current 1 60 nA VFB Feedback Voltage VITH = 0.4V (Note 5) 1.218 1.230 1.242 V ● 1.212 1.248 V VITH = 0.4V (Note 5), I-Grade (Note 2) ● 1.205 1.255 V IFB FB Pin Input Current VITH = 0.4V (Note 5) 18 60 nA ΔVFB Line Regulation 2.5V ≤ VIN ≤ 30V 0.002 0.02 %/V ΔVIN 2.5V ≤ VIN ≤ 30V, I-Grade (Note 2) ● 0.002 0.03 %/V ΔVFB Load Regulation VMODE/SYNC = 0V, VITH = 0.5V to 0.9V (Note 5) ● – 1 –0.1 % ΔVITH VMODE/SYNC = 0V, VITH = 0.5V to 0.9V (Note 5) ● – 1 –0.1 % I-Grade (Note 2) ΔVFB(OV) ΔFB Pin, Overvoltage Lockout VFB(OV) – VFB(NOM) in Percent 2.5 6 10 % gm Error Amplifi er Transconductance ITH Pin Load = ±5μA (Note 5) 650 μmho VITH(BURST) Burst Mode Operation ITH Pin Voltage Falling ITH Voltage (Note 5) 195 mV VSENSE(MAX) Maximum Current Sense Input Threshold Duty Cycle < 20% 120 150 180 mV Duty Cycle < 20%, I-Grade (Note 2) ● 100 200 mV ISENSE(ON) SENSE Pin Current (GATE High) VSENSE = 0V 35 50 μA ISENSE(OFF) SENSE Pin Current (GATE Low) VSENSE = 30V 0.1 5 μA
Oscillator
fOSC Oscillator Frequency RFREQ = 80k 250 300 350 kHz RFREQ = 80k, I-Grade (Note 2) ● 250 300 350 kHz Oscillator Frequency Range 50 1000 kHz I-Grade (Note 2) ● 50 1000 kHz DMAX Maximum Duty Cycle 87 92 97 % I-Grade (Note 2) ● 87 92 97 % fSYNC/fOSC Recommended Maximum Synchronized fOSC = 300kHz (Note 6) 1.25 1.30 Frequency Ratio fOSC = 300kHz (Note 6), I-Grade (Note 2) ● 1.25 1.30 tSYNC(MIN) MODE/SYNC Minimum Input Pulse Width VSYNC = 0V to 5V 25 ns tSYNC(MAX) MODE/SYNC Maximum Input Pulse Width VSYNC = 0V to 5V 0.8/fOSC ns VIL(MODE) Low Level MODE/SYNC Input Voltage 0.3 V I-Grade (Note 2) ● 0.3 V VIH(MODE) High Level MODE/SYNC Input Voltage 1.2 V I-Grade (Note 2) ● 1.2 V RMODE/SYNC MODE/SYNC Input Pull-Down Resistance 50 kΩ VFREQ Nominal FREQ Pin Voltage 0.62 V 18711fb 3