LTC3455 Datasheet, PDF (6/24 Pages) Linear Technology – Dual DC/DC Converter with USB Power Manager and Li-Ion Battery Charger

LTC3455
TYPICAL PERFOR A CE CHARACTERISTICS
Battery Charger Regulation
Voltage
4.30
4.25
4.20
4.15
4.10
4.05
4.00
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G13
Charge Current When
Wall-Powered
600
500
400
THERMAL CONTROL
LOOP IN OPERATION
300
200
100 VBAT = 3.6V
V_MAX = 4.5V
R_PROG = 2.49k
0
–50 –25 0 25 50 75
TEMPERATURE (°C)
100 125
3455 G16
PROG Pin Voltage
vs Charge Current
1.50
V_BAT = 3.6V
V_MAX = 4.5V
1.25 ^RPROG ^{= 2.49}
T_A = 25°C
1.00
0.75
0.50
0.25
0
0
100 200 300 400 500
CHARGE CURRENT (mA)
3455 G19
6
Battery Charger Recharge
Threshold
4.30
4.25
4.20
4.15
4.10
4.05
4.00
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G14
Charge Current When
USB-Powered
600
V_BAT = 3.6V
V_USB = 5V
500 ^RPROG ^{= 2.49k}
V_USBHP = 2V
400
THERMAL CONTROL
LOOP IN OPERATION
300
200
100
V_USBHP = 0V
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G17
R_DS(ON) for Switching Regulator
Power Switches
0.7
V_BAT = 3.6V
0.6
0.5
NMOS
0.4
PMOS
0.3
0.2
0.1
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G20
Battery Charger Trickle-Charge
Threshold
3.0
2.9
RISING
2.8
FALLING
2.7
2.6
2.5
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G15
Battery Current When
USB- or Wall-Powered
15.0
V_BAT = 4.2V
CHARGER OFF
12.5
10.0
7.5
5.0
2.5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G18
R_DS(ON) for V_MAX, USB, and HSO
PMOS Switches
1.4
V_HSI = 3.3V
1.2
V_USB = 5V
V_BAT = 3.6V
HSO
1.0
0.8
0.6
USB
0.4
0.2
V_MAX
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G21
3455f