Datasheet LTC4040 (Analog Devices) - 4

LTC4040
elecTrical characTerisTics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. (Note 3) VIN = 5V, VBAT = 3.6V, RPROG = 2k, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS NTC
VCOLD Cold Temperature Fault Threshold Voltage Rising Voltage Threshold 75.0 76.5 78 %VIN Hysteresis 1.5 %VIN VHOT Hot Temperature Fault Threshold Voltage Falling Voltage Threshold 33.4 34.9 36.4 %VIN Hysteresis 1.73 %VIN VDIS NTC Disable Threshold Voltage Falling Threshold 0.7 1.7 2.7 %VIN Hysteresis 50 mV INTC NTC Leakage Current –20 20 nA
Backup Mode Boost Switching Regulator
VBSTFB BSTFB Reference Voltage l 0.78 0.8 0.82 V IBSTFB BSTFB Input Bias Current –20 20 nA VSYS Step-up (Boost) Converter Output Voltage 3.5 5 V Range fOSCBST Step-Up Converter Switching Frequency Backup Mode (VPFI < 1.17V) 0.98 1.125 1.33 MHz ILIMBST NMOS Switch Current Limit 5.5 6.5 7.5 A RPBST Boost High Side Switch On-Resistance 75 mΩ RNBST Boost Low Side Switch On-Resistance 70 mΩ VOVSD VSYS Overvoltage Shutdown Threshold VSYS Rising 5.3 5.5 5.7 V Overvoltage Shutdown Hysteresis 100 mV VUVLO BAT Pin Undervoltage Lockout VBAT Falling 2.45 2.6 V BAT Pin Undervoltage Lockout Hysteresis 150 mV DMAX Maximum Boost Duty Cycle 88 93 % NMOS Switch Leakage BSTOFF = 1, CHGOFF = 1 1 µA PMOS Switch Leakage BSTOFF = 1, CHGOFF = 1 1 µA
Reset Comparator
RSTFB Threshold (Falling) l 0.72 0.74 0.76 V RSTFB Hysteresis 20 mV RSTFB Pin Leakage Current VRSTFB = 0.9V –50 50 nA RST Delay (RSTFB Rising) 232 ms
Power-Fail Comparator
PFI Input Threshold (Falling Edge) Initiates Backup Mode l 1.17 1.19 1.21 V PFI Input Hysteresis 30 mV PFI Pin Leakage Current VPFI = 1.3V –100 100 nA PFI Delay to PFO PFI Falling 0.5 µs PFO Pin Leakage Current VPFO = 5V 10 µA PFO Pin Output Low Voltage IPFO = 5mA 65 mV
Logic Input (CHGOFF, BSTOFF, F0, F1, F2)
VIL Logic Low Input Voltage l 0.4 V VIH Logic High Input Voltage l 1.2 V IIL Logic Low Input Leakage –1 1 µA IIH Logic High Input Leakage –1 1 µA 4040fb 4 For more information www.linear.com/LTC4040 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts