Datasheet LTC7817 (Analog Devices) - 3

LTC7817
ELECTRICAL CHARACTERISTICS The
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indicates specifications which apply over the specified operating junction temperature range, otherwise specifications are for TA = 25°C, VBIAS = 12V, RUN1,2,3 > 1.25V, EXTVCC = 0V, VPRG3 = FLOAT unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Input Supply (VBIAS, VIN)
VBIAS Bias Input Supply Operating Voltage Range 4.5 40 V VIN Boost Converter Input Supply Operating VBIAS ≥ 4.5V 1 40 V Range Front Page Circuit, 14V to 3.3V, No Load, 14 µA RUN2,3 = 0V
Controller Operation
VOUT1,2 Buck Output Voltage Operating Range 0.8 40 V VOUT3 Boost Output Voltage Operating Range 40 V VFB1,2 Buck Regulated Feedback Voltage (Note 4) VBIAS = 4.5V to 40V, ITH1,2 Voltage = 0.6V to 1.2V l 0.788 0.800 0.812 V 0ºC to 85ºC, All Grades 0.792 0.800 0.808 V VFB3 Boost Regulated Feedback Voltage (Note 4) VBIAS = 4.5V to 40V, ITH3 Voltage = 0.6V to 1.2V, VPRG3 = FLOAT l 1.177 1.195 1.213 V VPRG3 = 0V l 7.81 8.00 8.13 V VPRG3 = INTVCC l 9.77 10.0 10.17 V Buck Feedback Current ±5 ±50 nA Boost Feedback Current VPRG3 = FLOAT ±5 ±50 nA RUN3 = 0V, VPRG3 = 0V or INTVCC ±5 ±50 nA RUN3 = 2V, VPRG3 = 0V or INTVCC 1 µA Buck Feedback Overvoltage Protection Measured at VFB1,2 Relative to 7 10 13 % Threshold Regulated VFB1,2 gm1,2,3 Transconductance Amplifier gm (Note 4) ITH1,2,3=1.2V, Sink/Source=5μA 1.8 mmho V – SENSE(MAX) Maximum Current Sense Threshold VFB1,2 = 0.7V, VSENSE1,2 = 3.3V l 45 50 55 mV V + FB3 = 1.1V, VSENSE3 = 12V Matching for Channels 1 & 2 V – SENSE1,2 = 3.3V –3.5 0 3.5 mV I + + SENSE1,2 SENSE1,2+ Pin Current VSENSE1,2 = 3.3V ±1 µA I – – SENSE3 SENSE3– Pin Current VSENSE3 = 12V ±1 µA I – SENSE1– SENSE1– Pin Current VSENSE1 ≤ 2.7V 2 µA 3.2V ≤ V – SENSE1 < INTVCC – 0.5V 40 µA V – SENSE1 > INTVCC + 0.5V 660 µA I – SENSE2– SENSE2– Pin Current VSENSE2 = 3.3V ±2 µA V – SENSE2 > INTVCC + 0.5V 620 µA I + + SENSE3 SENSE3+ Pin Current VSENSE3 = 3.3V ±2 µA V + SENSE3 > INTVCC + 0.5V 660 µA Soft-Start Charge Current VTRACK/SS1,2 = 0V, VSS3 = 0 10 12.5 15 µA RUN Pin ON Threshold VRUN1,2,3 Rising l 1.15 1.20 1.25 V RUN Pin Hysteresis VRUN1,2,3 Falling 100 mV Rev 0 For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Typical Application Related Parts