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LTC4040_15 Datasheet, PDF (3/26 Pages) Linear Technology – 2.5A Battery Backup Power Manager
◁
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
VIN
Input Voltage Range
l 3.5
5.5
V
VBAT
Battery Voltage Range (Backup Boost Input)
2.7
5
V
IINQ
VIN Quiescent Current
Normal Mode (VPFI = 2V), Battery Charger Timed Out
Shutdown (BSTOFF = CHGOFF=1)
570
µA
3.5
7
µA
IBATQ
BAT Quiescent Current
Normal Mode (VPFI = 2V), Battery Charger Timed Out
Backup Mode (VIN = VPFI = 0V), No System Load
l
Shutdown (BSTOFF = CHGOFF = 1)
45
µA
40
70
µA
1.5
3
µA
Battery Charger
VCHG
BAT Regulated Output Voltage for LiFePO4 F2 = 0, F1 = 0, F0 = 0
Option (F2 = 0)
F2 = 0, F1 = 0, F0 = 1
F2 = 0, F1 = 1, F0 = 0
F2 = 0, F1 = 1, F0 = 1
l 3.42 3.45 3.48
V
l 3.47 3.50 3.53
V
l 3.52 3.55 3.58
V
l 3.57 3.60 3.63
V
BAT Regulated Output Voltage for Li-Ion
Option (F2 = 1)
F2 = 1, F1 = 0, F0 = 0
F2 = 1, F1 = 0, F0 = 1
F2 = 1, F1 = 1, F0 = 0
F2 = 1, F1 = 1, F0 = 1
l 3.92 3.95 3.98
V
l 3.97 4.00 4.03
V
l 4.02 4.05 4.08
V
l 4.07 4.10 4.13
V
ICHG
Regulated Battery Charge Current
RPROG = 2k
VSYS-to-VBAT Differential Undervoltage
Lockout Threshold (Falling)
950 1000 1050
mA
40
50
60
mV
VSYS-to-BAT Differential Undervoltage
Lockout Threshold (Rising)
125 145 165
mV
VPROG
hPROG
PROG Pin Servo Voltage
Ratio of Battery Current to PROG Pin Current
800
mV
2500
mA/
mA
ITRKL
Trickle Charge Current
VBAT = 2.5V, RPROG = 2k
125
mA
PROG Pin Servo Voltage at Trickle Charge VBAT = 2.5V, RPROG = 2k
100
mV
Input Current Limit Threshold Voltage
VIN – VCLN
l 23.5 25 26.5
mV
ACLPROG Input Current Limit Amplifier Gain
Ratio of CLPROG Voltage to (VIN – VCLN)
32
V/V
CLN Input Bias Current
VCLN = VIN
300
nA
VRECHG Recharge Battery Threshold Voltage
Threshold Voltage Relative to VCHG if F2 = 0 and F1 = 1
94.2 95 95.8
%
Threshold Voltage Relative to VCHG All Other Cases
96.7 97.5 98.3
%
tTERMINATE Safety Timer Termination Period
Timer Starts When VBAT = VCHG
F2 = 1 (Li-Ion)
F2 = 0 (LiFePO4)
3.7 4.25 5 Hours
1.85 2.13 2.5 Hours
VLOWBAT Low Battery Threshold Voltage for Trickle Charge VBAT Rising
2.75 2.85 2.95
V
�VLOWBAT Low Battery Hysteresis
150
mV
tBADBAT Bad-Battery Termination Time
VBAT < (VLOWBAT − ΔVLOWBAT)
0.47 0.54 0.64 Hours
VC/8
End-of-Charge Indication
PROG Pin Average Voltage
90 100 110
mV
fOSC(BUCK) Step-Down (Buck) Converter Switching
Frequency
Normal Mode (VPFI > 1.21V)
1.96 2.25 2.65 MHz
RP(BUCK)
RN(BUCK)
ILIM(BUCK)
High Side Switch On-Resistance
Low Side Switch On-Resistance
PMOS Switch Current Limit
Normal Mode (VPFI > 1.21V)
Normal Mode (VPFI > 1.21V)
130
mΩ
120
mΩ
3
4.3
A
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