LTC3455_15 Datasheet, PDF (5/28 Pages) Linear Technology – Dual DC/DC Converter with USB Power Manager and Li-Ion Battery Charger

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3455/LTC3455-1
Feedback Pins (FB1, FB2)
and AI Pin Voltage
815
810
805
AI
800
FB1
FB2
795
790
785
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G04
Switching Regulator Oscillator
Frequency
2.0
1.5
FOR BOTH SWITCHERS
1.0
0.5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G05
Switching Regulator Current Limit
1000
SWITCHER 2
800
600
SWITCHER 1
400
200
0
–50 –25
0 25 50 75
TEMPERATURE (oC)
100 125
3455 G06
USB Pin Current Limit
500
USBHP = 2V
400
300
200
100
USBHP = 0V
V_USB = 5V
0
–50 –25 0 25 50 75
TEMPERATURE (°C)
100 125
3455 G07
V_MAX Pin Current Limit
5.0
4.5
NORMAL OPERATION
4.0
3.5
3.0
2.5
2.0
1.5
1.0 ^STARTUP
0.5
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G08
HSO Pin Current Limit
200
150
100
50
V_HSI = 3.3V
V_HSO = 2.5V
0
–50 –25 0 25 50 75
TEMPERATURE (°C)
100 125
3455 G09
Battery Undervoltage Lockout
4.00
3.75
3.50
3.25
RISING
3.00
2.75
2.50
–50 –25
FALLING
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G10
USB Undervoltage Lockout
4.00
3.75
FALLING
RISING
3.50
3.25
3.00
2.75
2.50
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G11
WALLFB Trip Voltage
1.26
1.24
RISING
1.22
1.20
1.18
FALLING
1.16
1.14
1.12
1.10
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3455 G12
3455fc
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