LTC3355_15 Datasheet, PDF (3/20 Pages) Linear Technology – 20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

LTC3355
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 12V unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V_IN
V_IN Operating Voltage Range
l
3
20
V
I_Q
V_IN Quiescent Current
V_OUT Quiescent Current
Charger Off, Not Switching, V_OUT = 3.3V, No l 60
120
215
µA
Load, In Regulation, Supercapacitor Charged l 110
265
420
µA
V_FB
FB Reference Voltage
l 0.775
0.825
V
FB Line Regulation
V_OUT = 2.7V to 5V
0.1
%/V
I_FB
FB Input Bias Current
–20
20
nA
V_VOUT
V_OUT Voltage Range
l 2.7
5
V
V_OUT Overvoltage Limit
Buck or Boost Enabled
5.4
5.65
5.95
V
V_OUT Undervoltage Lockout Threshold Boost Enabled
1.8
2
2.2
V
V_INM5
V_IN-V_INM5
V_IN > 7V
4.65
V
V_INTVCC INTV_CC Internal Voltage Power Supply
2
5
V
V_VCAP
V_CAP Voltage Range
0
5
V
I_VCAP
V_CAP Current Accuracy
V_CAP = 2V, V_OUT = 3.3V, I_VCAP = 1A
–10
EN_CHG = High
10
%
V_ICHG
R_ICHG
I_CFB
V_CFB
V_CAP Programmable Current Range
I_CHG Reference Voltage
I_CHG Set Resistor Range
CFB Input Bias Current
CFB Reference Voltage
CFB Hysteresis
EN_CHG = High
EN_CHG = High
EN_CHG = High
EN_CHG = High
0.1
1
A
0.78
0.82
V
60.4
604
kΩ
–20
20
nA
0.78
0.8
0.82
V
30
mV
I_ICL
V_INS(CMI)
f_SW
CFB Overvoltage Hysteretic Comparator
Switch Point
V_IN Input Current Limit
V_INS Common Mode Range
Switching Frequency
Foldback Frequency (Buck Only)
CFB Rising
CFB Falling
V_INS-V_IN to Disable Charger
V_INS-V_IN to Disable Buck
FB ≥ 0.5V
FB ≤ 0.3V
V_CFB+0.035
V
V_CFB
V
37
43
mV
42
50
mV
3.0
20
V
0.75
1
1.25
MHz
100
kHz
V_PFI
PFI Falling Threshold
PFI Hysteresis
l 0.775
0.8
0.825
V
17
mV
I_PFI
PFI Leakage Current
1A Buck Regulator
–20
20
nA
I_SW1
SW1 Peak Current
PWM Mode (Note 5)
Burst Mode^® (Note 5)
1.3
1.65
2
A
0.5
A
t_SS
Soft-Start Time
DC Max Maximum Duty Cycle
FB = 0V
1000
µs
100
%
R_PMOS
I_LEAKP
PMOS On-Resistance
PMOS Leakage Current
Buck Disabled
0.5
1
Ω
–2
2
µA
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