LTC3552 Datasheet, PDF (4/24 Pages) Linear Technology – Standalone Linear Li-Ion Battery Charger and Dual Synchronous Buck Converter

LTC3552
ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime. Pins of regulators should not exceed 6V.
Note 2: The LTC3552E is guaranteed to meet performance specifications
from 0°C to 85°C Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Failure to solder the exposed backside of the package to the PC
board will result in a thermal resistance much higher than 40°C/W. See
Thermal Considerations.
Note 4: Supply current includes PROG pin current and ITERM pin current
(approximately 100µA each) but does not include any current delivered to
the battery through the BAT pin (approximately 100mA).
Note 5: The regulator is tested in a proprietary test mode that connects
V_FB to the output of the error amplifier.
Note 6: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 7: The regulator power switch on-resistances are guaranteed by
correlation to wafer level measurements.
Note 8: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
T_J = T_A + (P_D • θ_JA)
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C Unless Otherwise Specified.
Battery Charger
PROG Pin Voltage vs V_IN
(Constant-Current Mode)
1.015
1.010
V_BAT = 4V
R_PROG = 10k
1.005
PROG Pin Voltage
vs Temperature
1.0100
1.0075
1.0050
V_IN = 5V
V_BAT = 4V
R_PROG = 10k
1.0025
Charge Current
vs PROG Pin Voltage
600
V_IN = 5V
R_PROG = 2k
500 R_ITERM = 2k
400
1.000
1.0000
300
0.9975
0.995
200
0.9950
0.990
100
0.9925
0.985
4 4.5 5 5.5 6 6.5 7 7.5 8
V_IN (V)
3552 G01
0.9900
–50 –25 0
25 50 75 100
TEMPERATURE (°C)
3552 G02
0
0 0.2 0.4 0.6 0.8
V_PROG (V)
1 1.2
3552 G03
Regulated Output (Float) Voltage
vs Charge Current
4.26
V_IN = 5V
4.24 ^RPROG ^{= 1.25k}
4.22
4.20
4.18
4.16
4.14
4.12
4.10
0 100 200 300 400 500 600 700
I_BAT (mA)
3552 G04
4
Regulated Output (Float) Voltage
vs Temperature
4.215
4.210
V_IN = 5V
R_PROG = 10k
4.205
4.200
4.195
4.190
4.185
–50 –25 0
25 50
TEMPERATURE (°C)
75 100
3552 G05
Regulated Output (Float)
Voltage vs V_IN
4.215
R_PROG = 10k
4.210
4.205
4.200
4.195
4.190
4.185
4 4.5 5 5.5 6 6.5 7 7.5 8
V_IN (V)
3552 G06
3552f