LTC3554 Datasheet, PDF (6/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

LTC3554
ELECTRICAL CHARACTERISTICS
Note 3. This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperatures will exceed 110°C when overtemperature protection is
active. Continuous operation above the specified maximum operating
junction temperature may result in device degradation or failure.
Note 4. V_CC is the greater of V_BUS or BAT.
Note 5. Total Battery Drain Current is the sum of I_BATQ and I_OUT. For
example, in applications where the buck input (BVIN pin) is connected
to the PowerPath output (V_OUT pin) such that I_OUT = I_BVIN, total battery
drain current = I_BATQ + I_BVIN.
Note 6. hC/10 is expressed as a fraction of programmed full charge
current with specified PROG resistor.
Note 7. The current limit features of this part are intended to protect
the IC from short term or intermittent fault conditions. Continuous
operation above the absolute maximum specified pin current rating may
result in device degradation or failure.
Note 8. FB High, Not Switching
Note 9. V_OUT not in UVLO.
Note 10. PGOOD threshold is expressed as a percentage difference from
the buck regulation voltage. The threshold is measured with the buck
feedback pin voltage rising.
Note 11. See the Operation section of this data sheet for detailed
explanation of the pushbutton state machine and the effects of each
state on switching regulator and power manager operation.
Note 12. If V_BUS < V_UVLO then V_FWD = 0 and the forward voltage across
the ideal diode is equal to its current times R_DROPOUT.
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C, unless otherwise specified.
V_BUS Supply Current
vs Temperature
400 _{VBUS = 5V}
HPWR = L
350
300
250
200
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
V_BUS Supply Current
vs Temperature (Suspend Mode)
25
V_BUS = 5V
20
15
10
5
0
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
Battery Drain Current
vs Temperature
14
V_BAT = 3.8V
STBY = 3.8V
12 _{REGULATORS LOAD = 0}
BOTH REGULATORS
10 _ENABLED
8
ONE REGULATOR ENABLED
6
BOTH REGULATORS DISABLED
4
2
HARD RESET
0
–75 –50 –25 0 25 50 75
TEMPERATURE (°C)
100 125
3554 G01
3554 G02
3554 G03
Battery Drain Current
vs Temperature (Suspend Mode)
5
V_BUS = 5V
V_BAT = 3.8V
4
3
2
1
0
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3554 G03b
V_BUS Current Limit
vs Temperature
500
V_BUS = 5V
HPWR = H
400
300
200
HPWR = L
100
0
–75 –50 –25 0 25 50 75 100 125
TEMPERATURE (°C)
3554 G04
V_BUS and Battery Current
vs Load Current
600
R_PROG = 1.74k
500
I_VBUS
400
I_LOAD
300
200
I_BAT
(CHARGING)
100
0
–100
0
I_BAT
(DISCHARGING)
100 200 300 400 500
LOAD CURRENT (mA)
3554 G05
3554p
6