Datasheet LTC1871 (Analog Devices) - 3

LTC1871
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 = VINTVCC = 5V, VRUN = 1.5V, RFREQ = 80k, VMODE/SYNC = 0V, unless otherwise specifi ed. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loop
VIN(MIN) Minimum Input Voltage 2.5 V I-Grade or H-Grade (Note 2) ● 2.5 V IQ Input Voltage Supply Current (Note 4) Continuous Mode VMODE/SYNC = 5V, VFB = 1.4V, VITH = 0.75V 550 1000 μA VMODE/SYNC = 5V, VFB = 1.4V, VITH = 0.75V, ● 550 1000 μA I-Grade or H-Grade (Note 2) Burst Mode Operation, No Load VMODE/SYNC = 0V, VITH = 0.2V (Note 5) 250 500 μA VMODE/SYNC = 0V, VITH = 0.2V (Note 5), ● 250 500 μA I-Grade or H-Grade (Note 2) Shutdown Mode VRUN = 0V 10 20 μA VRUN = 0V, I-Grade or H-Grade (Note 2) ● 10 20 μA 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 H-Grade (Note 2) ● 1.179 1.315 V VRUN(HYST) RUN Pin Input Threshold Hysteresis 50 100 150 mV I-Grade (Note 2) ● 35 100 175 mV H-Grade (Note 2) ● 35 300 mV IRUN RUN Input Current 1 60 nA VFB Feedback Voltage VITH = 0.2V (Note 5) 1.218 1.230 1.242 V ● 1.212 1.248 V VITH = 0.2V (Note 5), I-Grade or H-Grade (Note 2) ● 1.205 1.255 V IFB FB Pin Input Current VITH = 0.2V (Note 5) 18 60 nA ΔVFB Line Regulation 2.5V ≤ VIN ≤ 30V 0.002 0.02 %/V ΔVIN 2.5V ≤ VIN ≤ 30V, I-Grade or H-Grade (Note 2) ● 0.002 0.02 %/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 or H-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) 0.3 V VSENSE(MAX) Maximum Current Sense Input Threshold Duty Cycle < 20% 120 150 180 mV Duty Cycle < 20%, I-Grade or H-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 RFREQ = 80k, H-Grade (Note 2) ● 240 300 360 kHz Oscillator Frequency Range 50 1000 kHz I-Grade or H-Grade (Note 2) ● 50 1000 kHz 1871fe 3