LTC4040_15 Datasheet, PDF (4/26 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 T_A = 25°C. (Note 3) V_IN = 5V, V_BAT = 3.6V, R_PROG = 2k, unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
NTC
V_COLD
V_HOT
V_DIS
Cold Temperature Fault Threshold Voltage
Hot Temperature Fault Threshold Voltage
NTC Disable Threshold Voltage
Rising Voltage Threshold
Hysteresis
Falling Voltage Threshold
Hysteresis
Falling Threshold
Hysteresis
75.0 76.5 78
1.5
33.4 34.9 36.4
1.73
0.7 1.7 2.7
50
%V_IN
%V_IN
%V_IN
%V_IN
%V_IN
mV
I_NTC
NTC Leakage Current
Backup Mode Boost Switching Regulator
–20
20
nA
V_BSTFB
I_BSTFB
V_SYS
BSTFB Reference Voltage
BSTFB Input Bias Current
Step-up (Boost) Converter Output Voltage
Range
l 0.78 0.8 0.82
V
–20
20
nA
3.5
5
V
f_OSCBST
I_LIMBST
R_PBST
R_NBST
V_OVSD
Step-Up Converter Switching Frequency
NMOS Switch Current Limit
Boost High Side Switch On-Resistance
Boost Low Side Switch On-Resistance
V_SYS Overvoltage Shutdown Threshold
Overvoltage Shutdown Hysteresis
Backup Mode (V_PFI < 1.17V)
V_SYS Rising
0.98 1.125 1.33 MHz
5.5 6.5 7.5
A
75
mΩ
70
mΩ
5.3 5.5 5.7
V
100
mV
V_UVLO
BAT Pin Undervoltage Lockout
BAT Pin Undervoltage Lockout Hysteresis
V_BAT Falling
2.45 2.6
V
150
mV
D_MAX
Maximum Boost Duty Cycle
NMOS Switch Leakage
BSTOFF = 1, CHGOFF = 1
88
91
%
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
RST Delay (RSTFB Rising)
V_RSTFB = 0.9V
–50
50
nA
232
ms
Power-Fail Comparator
PFI Input Threshold (Falling Edge)
PFI Input Hysteresis
Initiates Backup Mode
l 1.17 1.19 1.21
V
30
mV
PFI Pin Leakage Current
PFI Delay to PFO
V_PFI = 1.3V
PFI Falling
–100
100
nA
0.5
µs
PFO Pin Leakage Current
PFO Pin Output Low Voltage
Logic Input (CHGOFF, BSTOFF, F0, F1, F2)
V_IL
Logic Low Input Voltage
V_IH
Logic High Input Voltage
I_IL
Logic Low Input Leakage
I_IH
Logic High Input Leakage
V_PFO = 5V
I_PFO = 5mA
10
µA
65
mV
l
l 1.2
–1
–1
0.4
V
V
1
µA
1
µA
4040fa
4
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