Electrical Specifications Subject to Change
FEATURES
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LTC3554
Micropower USB Power
Manager With Li-Ion Charger
and Two Step-Down Regulators
DESCRIPTION
The LTC
®
3554 is a micropower, highly integrated power
management and battery charger IC for single-cell
Li-Ion/Polymer battery applications. It includes a
PowerPath manager with automatic load prioritization,
a battery charger, an ideal diode and numerous internal
protection features. Designed specifically for USB applica-
tions, the LTC3554 power manager automatically limits
input current to a maximum of either 100mA or 500mA.
Battery charge current is automatically reduced such that
the sum of the load current and the charge current does not
exceed the selected input current limit. The LTC3554 also
includes two synchronous step-down switching regulators
as well as a pushbutton controller. With all supplies enabled
in standby mode, the quiescent current drawn from the
battery is only 10μA. The LTC3554 is available in a 3mm
×
3mm
×
0.55mm 20-pin UTQFN package.
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation. PowerPath
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents, including 6522118, 6700364, and other patents
pending.
10μA Standby Mode with All Outputs On
Seamless Transition Between Input Power Sources:
Li-Ion/Polymer Battery and USB
240mΩ Internal Ideal Diode Provides Low Loss
PowerPath™
Dual High Efficiency Step-Down Switching Regulators
(200mA I
OUT
) with Adjustable Output Voltages
Pushbutton On/Off Control with System Reset
Full Featured Li-Ion/Polymer Battery Charger
Programmable Charge Current with Thermal Limiting
Instant-On Operation with Discharged Battery
Compact Ultra-Thin 3mm
×
3mm
×
0.55mm 20-Pin
UTQFN Package
APPLICATIONS
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USB-Based Handheld Products
Portable Li-Ion/Polymer Based Electronic Devices
TYPICAL APPLICATION
4.35V TO 5.5V
USB INPUT
100k
NTC
100k
T
PROG
1.74k
LTC3554
BAT
Li-Ion
BATTERY
CHRG
V
BUS
V
OUT
10μF
SYSTEM
LOAD
Battery Drain Current
vs Temperature
14
BATTERY DRAIN CURRENT (μA)
V
BAT
= 3.8V
STBY = 3.8V
12 REGULATORS LOAD = 0
BOTH REGULATORS
10 ENABLED
8
6
4
2
HARD RESET
0
–75 –50 –25 0
25 50 75
TEMPERATURE (°C)
ONE REGULATOR ENABLED
BOTH REGULATORS DISABLED
HPWR
SUSP
BVIN
2.2μF
4.7μH
PWR_ON1
SW1
10pF
2.05M
10μF
3.3V
200mA
FSEL
STBY
PGOOD
PWR_ON2
PBSTAT
ON
ON/OFF
FB1
649k
10μH
SW2
10pF
FB2
649k
3554 TA01a
100 125
3554 TA01b
1.2V
200mA
332k
10μF
3554p
1
LTC3554
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2, 3)
PIN CONFIGURATION
TOP VIEW
PROG
15 NTC
14
CHRG
21
13 SW1
12 BVIN
11 SW2
6
FB1
7
FB2
8
PWR_ON2
9 10
PWR_ON1
STBY
SUSP
V
BUS
V
OUT
BAT
V
BUS
, V
OUT
, BVIN
t < 1ms and Duty Cycle < 1% .................. –0.3V to 7V
Steady State............................................. –0.3V to 6V
BAT, NTC,
CHRG,
SUSP PBSTAT,
,
ON,
PGOOD, FB1, FB2.................................. –0.3V to 6V
PWR_ON1, PWR_ON2, STBY
HPWR, FSEL (Note 4) ......................–0.3V to V
CC
+ 0.3V
I
VBUS
, I
BAT
...................................................................1A
I
SW1
, I
SW2
(Continuous).......................................300mA
I
CHRG
, I
PGOOD,
I
PBSTAT
............................................75mA
Operating Temperature Range.................. –40°C to 85°C
Junction Temperature ........................................... 110°C
Storage Temperature Range................... –65°C to 125°C
20 19 18 17 16
HPWR 1
FSEL 2
PBSTAT 3
PGOOD 4
ON
5
PD PACKAGE
20-LEAD (3mm
×
3mm) PLASTIC UTQFN
T
JMAX
= 110°C,
θ
JA
= 70°C/W
EXPOSED PAD (PIN 21) IS GND, AND MUST BE SOLDERED TO PCB GND
ORDER INFORMATION
LEAD FREE FINISH
LTC3554EPD#PBF
TAPE AND REEL
LTC3554EPD#TRPBF
PART MARKING
FDPT
PACKAGE DESCRIPTION
20-Lead (3mm × 3mm) Plastic UTQFN
TEMPERATURE RANGE
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
POWER MANAGER ELECTRICAL CHARACTERISTICS
SYMBOL
I
BATQ
PARAMETER
Battery Drain Current
CONDITIONS
I
OUT
= 0 (Note 5)
V
BUS
= 0V (Hard Reset)
V
BUS
= 0V
V
BUS
= 0V, PWR_ON1 = PWR_ON2 = 3.8V
V
BAT
= V
FLOAT
, Timer Timed Out
100mA, 500mA Modes
SUSP = 5V (Suspend Mode)
V
BVIN
= 3.8V, V
BUS
= 0V (Note 8)
PWR_ON1 = STBY = 3.8V
PWR_ON1 = PWR_ON2 = STBY = 3.8V
PWR_ON1 = 3.8V, STBY = 0V
PWR_ON1 = PWR_ON2 = 3.8V, STBY = 0V
No-Load Quiescent Currents
The
l
denotes specifications that apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C,
V
BUS
= 5V, V
BAT
= 3.8V, HPWR = SUSP = PWR_ON1 = PWR_ON2 = 0V, R
PROG
= 1.74k, STBY = High
MIN
TYP
MAX
UNITS
0.2
3
6.5
5
300
15
0.01
1.5
3
18
36
4.35
2
5
12
8
500
30
1
3
6
35
70
5.5
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
V
mA
mA
3554p
I
BATQC
I
BUSQ
I
BVINQ
Battery Drain Current, V
BUS
Available
V
BUS
Input Current
BVIN Input Current
Shutdown Input Current
One Buck Enabled, Standby Mode
Both Bucks Enabled, Standby Mode
One Buck Enabled
Both Bucks Enabled
Input Supply Voltage
Total Input Current
Input Power Supply
V
BUS
I
BUS(LIM)
HPWR = 0V (100mA)
HPWR = 5V (500mA)
l
l
TBD
TBD
90
450
100
500
2
LTC3554
POWER MANAGER ELECTRICAL CHARACTERISTICS
SYMBOL
V
UVLO
V
DUVLO
R
ON_ILIM
PARAMETER
V
BUS
Undervoltage Lockout
V
BUS
to BAT Differential Undervoltage
Lockout
Input Current Limit Power FET
On-Resistance (Between V
BUS
and V
OUT
)
V
BAT
Regulated Output Voltage
0 ≤ T
A
≤ 85°C
I
CHG
V
PROG
V
PROG,TRKL
h
PROG
I
TRKL
V
TRKL
ΔV
RECHRG
t
TERM
t
BADBAT
h
C/10
R
ON_CHG
T
LIM
NTC
V
COLD
V
HOT
V
DIS
I
NTC
Ideal Diode
V
FWD
R
DROPOUT
I
MAX
V
IL
V
IH
R
PD
V
OL
I
CHRG
Forward Voltage Detection
Diode On-Resistance, Dropout
Diode Current Limit
Input Low Voltage
Input High Voltage
Internal Pull-Down Resistance
Output Low Voltage
Output Hi-Z Leakage Current
I
CHRG
= 5mA
V
BAT
= 4.5V, V
CHRG
= 5V
4
65
0
100
1
(Note 12)
I
OUT
= 200mA, V
BUS
= 0V
(Note 7)
0.4
1.2
15
240
1
mV
mΩ
A
V
V
MΩ
mV
μA
Cold Temperature Fault Threshold
Voltage
Rising NTC Voltage
Hysteresis
75
34
l
The
l
denotes specifications that apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C,
V
BUS
= 5V, V
BAT
= 3.8V, HPWR = SUSP = PWR_ON1 = PWR_ON2 = 0V, R
PROG
= 1.74k, STBY = High
CONDITIONS
Rising Threshold
Falling Threshold
Rising Threshold
Falling Threshold
MIN
3.5
0
TYP
3.8
3.6
200
50
350
MAX
3.9
300
UNITS
V
mV
mV
mV
mΩ
Battery Charger
V
FLOAT
4.179
4.165
l
4.2
4.2
431
1
0.1
750
4.221
4.235
453
V
V
mA
V
V
mA/mA
Constant-Current Mode Charge Current
R
PROG
= 1.74k
410
PROG Pin Servo Voltage
PROG Pin Servo Voltage in Trickle Charge V
BAT
< V
TRKL
Ratio of I
BAT
to PROG Pin Current
Trickle Charge Current
Trickle Charge Threshold Voltage
Recharge Battery Threshold Voltage
Safety Timer Termination Period
Bad Battery Termination Time
End-of-Charge Indication Current Ratio
Battery Charger Power FET
On-Resistance (Between V
OUT
and BAT)
Junction Temperature in Constant
Temperature Mode
V
BAT
< V
TRKL
V
BAT
Rising
V
BAT
Falling
Threshold Voltage Relative to V
FLOAT
Timer Starts when V
BAT
= V
FLOAT
– 50mV
V
BAT
< V
TRKL
(Note 6)
I
BAT
= 200mA
34
2.6
–85
3.2
0.4
0.085
43
2.9
2.75
–100
4
0.5
0.1
220
110
52
3
–115
4.8
0.6
0.115
mA
V
V
mV
Hour
Hour
mA/mA
mΩ
°C
76
1.3
35
1.3
1.7
50
77
36
2.2
50
%V
BUS
%V
BUS
%V
BUS
%V
BUS
%V
BUS
mV
nA
Hot Temperature Fault Threshold Voltage Falling NTC Voltage
Hysteresis
NTC Disable Threshold Voltage
NTC Leakage Current
Falling NTC Voltage
Hysteresis
V
NTC
= V
BUS
= 5V
1.2
–50
Logic Inputs (HPWR, SUSP)
Logic Output (CHRG)
3554p
3
LTC3554
SWITCHING REGULATOR ELECTRICAL CHARACTERISTICS
SYMBOL
BVIN
V
OUT
UVLO
PARAMETER
Input Supply Voltage
V
OUT
Falling
V
OUT
Rising
Oscillator Frequency
FB1 Input Current (Note 8)
FB2 Input Current (Note 8)
SW1 Pull-Down in Shutdown
SW2 Pull-Down in Shutdown
Input High Voltage
Input Low Voltage
Input Current
Switching Regulator 1 in Normal Operation (STBY Low)
I
LIM1
V
FB1
D1
R
P1
R
N1
V
FB1_LOW
I
SHORT1_SB
V
DROP1_SB
Peak PMOS Current Limit
Regulated Feedback Voltage
Max Duty Cycle
R
DS(ON)
of PMOS
R
DS(ON)
of NMOS
Feedback Voltage Threshold
Short-Circuit Current
Standby Mode Dropout Voltage
PWR_ON1 = 2.9V, I
SW1
= 5mA, V
FB1
= 0.77V,
V
OUT
= 2.9V, BVIN = 2.9V
PWR_ON2 = 3.8V (Note 7)
PWR_ON2 = 3.8V
I
SW2
= 100mA
I
SW2
= –100mA
PWR_ON2 = 3.8V, V
FB2
Falling
PWR_ON2 = 2.9V, I
SW2
= 5mA, V
FB2
= 0.77V,
V
OUT
= 2.9V, BVIN = 2.9V
l
l
The
l
denotes specifications that apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
OUT
= BVIN = 3.8V, PWR_ON1 = PWR_ON2 = 0V, unless otherwise noted.
CONDITIONS
l
MIN
2.7
2.5
TYP
2.6
2.8
2.25
1.125
MAX
5.5
2.9
2.59
1.295
0.05
0.05
UNITS
V
V
V
MHz
MHz
μA
μA
kΩ
kΩ
BVIN Connected to V
OUT
Through Low
Impedance. V
OUT
UVLO Disables the
Switching Regulators.
FSEL High
FSEL Low
F
OSC
I
FB1
I
FB2
R
SW1_PD
R
SW2_PD
1.91
0.955
–0.05
–0.05
PWR_ON1 = 0V
PWR_ON2 = 0V
10
10
0.8
0.4
–1
0.7
1
400
800
1.1
0.7
l
Logic Input Pins (FSEL, STBY)
1.2
V
V
μA
mA
mV
%
Ω
Ω
820
50
60
mV
mA
mV
PWR_ON1 = 3.8V (Note 7)
PWR_ON1 = 3.8V
I
SW1
= 100mA
I
SW1
= –100mA
PWR_ON1 = 3.8V, V
FB1
Falling
l
300
780
100
500
820
Switching Regulator 1 in Standby Mode (STBY High)
770
15
800
25
30
Switching Regulator 2 in Normal Operation (STBY Low)
I
LIM2
V
FB2
D2
R
P2
R
N2
V
FB2_LOW
I
SHORT2_SB
V
DROP2_SB
Peak PMOS Current Limit
Regulated Feedback Voltage
Max Duty Cycle
R
DS(ON)
of PMOS
R
DS(ON)
of NMOS
Feedback Voltage Threshold
Short-Circuit Current
Standby Mode Dropout Voltage
300
780
100
1.1
0.7
770
15
800
25
30
820
50
60
400
800
500
820
mA
mV
%
Ω
Ω
mV
mA
mV
Switching Regulator 2 in Standby Mode (STBY High)
3554p
4
LTC3554
PUSHBUTTON INTERFACE ELECTRICAL CHARACTERISTICS
The
l
denotes specifications that apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
BAT
= 3.8V unless otherwise noted.
SYMBOL
V
CC_PB
V
ON_TH
I
ON
R
PB_PU
V
PWR_ONx
I
PWR_ONx
I
PBSTAT
V
PBSTAT
I
PGOOD
V
PGOOD
V
THPGOOD
t
ON_PBSTATL
t
ON_PBSTATH
t
ON_PUP
t
ON_HR
t
PBSTAT_PW
t
EXTPWR
t
PON_UP
t
PON_DIS
t
PUP
t
PDN
t
PGOODH
t
PGOODL
PARAMETER
Pushbutton Operating Supply Range
ON
Threshold Rising
ON
Threshold Falling
ON
Input Current
Pushbutton Pull-Up Resistance
PWR_ONx Threshold Rising
PWR_ONx Threshold Falling
PWR_ONx Input Current
PBSTAT Output High Leakage Current
PBSTAT Output Low Voltage
PGOOD Output High Leakage Current
PGOOD Output Low Voltage
PGOOD Threshold Voltage
V
PBSTAT
= 3V
I
PBSTAT
= 3mA
V
PGOOD
= 3V
I
PGOOD
= 3mA
(Note 10)
–1
0.1
–8
50
900
400
4
40
5
50
100
900
1
5
1
All Enabled Bucks Within PGOOD Threshold
Voltage
All Bucks Disabled
230
100
6
V
ON
= V
CC
(Note 4)
Pull-Up to V
CC
(Note 4)
CONDITIONS
(Notes 4 , 9)
l
MIN
2.7
0.4
–1
200
TYP
MAX
5.5
UNITS
V
V
V
μA
kΩ
V
V
μA
μA
V
μA
V
%
ms
μs
ms
s
ms
ms
μs
μs
s
s
ms
μs
Pushbutton Pin (ON)
0.8
0.7
400
0.8
0.7
1.2
1
600
1.2
1
1
0.1
0.4
1
0.4
Logic Input Pins (PWR_ON1, PWR_ON2)
0.4
–1
–1
Status Output Pins (PBSTAT, PGOOD)
Pushbutton Timing Parameters (Note 11)
Minimum
ON
Low Time to Cause PBSTAT
ON
Brought Low During Power-On (PON) or
Low
Power-Up (PUP1, PUP2) States
Delay from
ON
High to PBSTAT High
Minimum
ON
Low Time to Enter
Power-Up (PUP1 or PUP2) State
Minimum
ON
Low Time to Hard Reset
PBSTAT Minimum Pulse Width
Power-On (PON) State, After PBSTAT Has
Been Low for at Least t
PBSTAT_PW
Starting in the Hard Reset (HR) or Power-Off
(POFF) States
ON
Brought Low During the Power-On (PON)
or Power-Up (PUP1, PUP2) States
Power-On (PON) or Power-Up (PUP1, PUP2)
States
Power-Up from USB Present to Power-Up Starting in the Hard Reset (HR) or Power-Off
(PUP1 or PUP2) State
(POFF) States
Any PWR_ONx High to Power-On State
PWR_ONx Low to Buckx Disabled
Power-Up (PUP1 or PUP2) State Duration
Power-Down (PDN1 or PDN2) State
Duration
Bucks in Regulation to PGOOD High
Bucks Disabled to PGOOD Low
Starting With Both PWR_ONx Low in the
Power-Off (POFF) State
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.
Note 2.
The LTC3554 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.
3554p
5
