Datasheet
LTC3555/LTC3555-X
3
3555fd
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
h
CLPROG
(Note 4)
Ratio of Measured V
BUS
Current to
CLPROG Program Current
1x Mode
5x Mode
10x Mode
Suspend Mode
224
1133
2140
11.3
mA/mA
mA/mA
mA/mA
mA/mA
I
OUT(POWERPATH)
V
OUT
Current Available Before
Loading BAT
1x Mode, BAT = 3.3V
5x Mode, BAT = 3.3V
10x Mode, BAT = 3.3V
Suspend Mode
135
672
1251
0.32
mA
mA
mA
mA
V
CLPROG
CLPROG Servo Voltage in Current
Limit
1x, 5x, 10x Modes
Suspend Mode
1.188
100
V
mV
V
UVLO_VBUS
V
BUS
Undervoltage Lockout Rising Threshold
Falling Threshold
3.95
4.30
4.00
4.35 V
V
V
UVLO_VBUS-BAT
V
BUS
to BAT Differential Undervoltage
Lockout
Rising Threshold
Falling Threshold
200
50
mV
mV
V
OUT
V
OUT
Voltage 1x, 5x, 10x Modes, 0V < BAT < 4.2V,
I
OUT
= 0mA, Battery Charger Off
3.4 BAT + 0.3 4.7 V
USB Suspend Mode, I
VOUT
= 250µA 4.5 4.6 4.7 V
f
OSC
Switching Frequency 1.8 2.25 2.7 MHz
R
PMOS_POWERPATH
PMOS On Resistance 0.18 Ω
R
NMOS_POWERPATH
NMOS On Resistance 0.30 Ω
I
PEAK_POWERPATH
Peak Switch Current Limit 1x, 5x Modes
10x
2
3
A
A
Battery Charger
V
FLOAT
BAT Regulated Output Voltage LTC3555/LTC3555-1
LTC3555/LTC3555-1
LTC3555-3
LTC3555-3
l
l
4.179
4.165
4.079
4.065
4.200
4.200
4.100
4.100
4.221
4.235
4.121
4.135
V
V
V
V
I
CHG
Constant Current Mode Charge
Current
R
PROG
= 1k
R
PROG
= 5k
980
185
1022
204
1065
223
mA
mA
I
BAT
Battery Drain Current V
BUS
> V
UVLO
, Battery Charger Off, I
VOUT
= 0µA
V
BUS
= 0V, I
VOUT
= 0µA (Ideal Diode Mode)
LTC3555
LTC3555-1/LTC3555-3
2 3.5
27
32
5
38
44
µA
µA
µA
V
PROG
PROG Pin Servo Voltage 1.000 V
V
PROG_TRKL
PROG Pin Servo Voltage in Trickle
Charge
BAT < V
TRKL
0.100 V
V
C/10
C/10 Threshold Voltage at PROG 100 mV
h
PROG
Ratio of I
BAT
to PROG Pin Current 1022 mA/mA
I
TRKL
Trickle Charge Current BAT < V
TRKL
100 mA
V
TRKL
Trickle Charge Threshold Voltage BAT Rising 2.7 2.85 3.0 V
ΔV
TRKL
Trickle Charge Hysteresis Voltage 135 mV
ΔV
RECHRG
Recharge Battery Threshold Voltage Threshold Voltage Relative to V
FLOAT
–75 –100 –125 mV
t
TERM
Safety Timer Termination Timer Starts when BAT = V
FLOAT
3.3 4 5 Hour
t
BADBAT
Bad Battery Termination Time BAT < V
TRKL
0.42 0.5 0.63 Hour
h
C/10
End of Charge Indication Current Ratio (Note 5) 0.088 0.1 0.112 mA/mA
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, BAT = 3.8V, DV
CC
= 3.3V, R
PROG
= 1k, R
CLPROG
= 3k,
unless otherwise noted.