Datasheet LTC4120, LTC4120-4.2 (Analog Devices) - 4

LTC4120/LTC4120-4.2
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). VIN = VRUN = 15V, VCHGSNS = VBAT = 4V, RPROG = 3.01k, VFB = 2.29V (LTC4120), VBATSNS = 4V (LTC4120-4.2). Current into a pin is positive out of the pin is negative. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ILOWBAT Low Battery Linear Charge Current 0V < VFB < VTRKL, VBAT = 2.6V (LTC4120), 6 9 16 mA VBATSNS < VTRKL_4.2, VBAT = 2.6V (LTC4120-4.2) VLOWBAT Low Battery Threshold Voltage VBAT Rising (LTC4120), l 2.15 2.21 2.28 V VBATSNS Rising (LTC4120-4.2) Hysteresis 147 mV ITRKL Switch Mode Trickle Charge Current VLOWBAT < VBAT, VFB < VTRKL (LTC4120) (Note 5), ICHG/10 mA VLOWBAT < VBATSNS < VTRKL_4.2 (LTC4120-4.2) PROG Pin Servo Voltage in Switch Mode VLOWBAT < VBAT, VFB < VTRKL (LTC4120) (Note 5), 122 mV Trickle Charge VLOWBAT < VBATSNS < VTRKL_4.2 (LTC4120-4.2) VTRKL Trickle Charge Threshold VFB Rising (LTC4120) (Note 5) l 1.64 1.68 1.71 V Hysteresis VFB Falling (LTC4120) (Note 5) 50 mV VTRKL_4.2 Trickle Charge Threshold VBATSNS Rising (LTC4120-4.2) l 2.86 2.91 2.98 V Hysteresis VBATSNS Falling (LTC4120-4.2) 88 mV hC/10 End of Charge Indication Current Ratio (Note 6) 0.1 mA/mA Safety Timer Termination Period 1.3 2.0 2.8 Hours Bad Battery Termination Timeout 19 30 42 Minutes
Switcher
fOSC Switching Frequency FREQ = INTVCC l 1.0 1.5 2.0 MHz FREQ = GND l 0.5 0.75 1.0 MHz tMIN(ON) Minimum Controllable On-Time (Note 9) 120 ns Duty Cycle Maximum (Note 9) 94 % Top Switch RDS(ON) ISW = –100mA 0.8 Ω Bottom Switch RDS(ON) ISW = 100mA 0.5 Ω IPEAK Peak Current Limit Measured Across RSNS with a 15µH Inductor in 585 750 1250 mA Series with RSNS (Note 9) ISW Switch Pin Current (Note 8) VIN = Open-Circuit, VRUN = 0V, VSW = 8.4V (LTC4120) l 15 30 µA VIN = Open-Circuit, VRUN = 0V, VSW = 4.2V l 7 15 µA (LTC4120-4.2)
Status Pins FAULT, CHRG
Pin Output Voltage Low I = 2mA 500 mV Pin Leakage Current V = 43V, Pin High Impedance 0 1 µA
NTC
Cold Temperature VNTC/VINTVCC Fault Rising VNTC Threshold l 73 74 75 %INTVCC Falling VNTC Threshold 72 %INTVCC Hot Temperature VNTC/VINTVCC Fault Falling VNTC Threshold l 35.5 36.5 37.5 %INTVCC Rising VNTC Threshold 37.5 %INTVCC NTC Disable Voltage Falling VNTC Threshold l 1 2 3 %INTVCC Rising VNTC Threshold 3 %INTVCC NTC Input Leakage Current VNTC = VINTVCC –50 50 nA Rev. G 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Operation Applications Information Package Description Revision History Typical Application Related Parts