FEATURES
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LTC3577-3/LTC3577-4
Highly Integrated
Portable Product PMIC
DESCRIPTION
The LTC
®
3577-3/LTC3577-4 are highly integrated power
management ICs for single cell Li-Ion/Polymer battery ap-
plications. It includes a PowerPath manager with automatic
load prioritization, a battery charger, an ideal diode, input
overvoltage protection and numerous other internal pro-
tection features. The LTC3577-3/LTC3577-4 are designed
to accurately charge from current limited supplies such as
USB by automatically reducing charge current such that
the sum of the load current and the charge current does
not exceed the programmed input current limit (100mA or
500mA modes). The LTC3577-3/LTC3577-4 reduce the bat-
tery voltage at elevated temperatures to improve safety and
reliability. The three step-down switching regulators and
two LDOs provide a wide range of available supplies. The
LTC3577-3/LTC3577-4 also include a pushbutton input to
control power sequencing and system reset. The onboard
LED backlight boost circuitry can drive up to 10 series
LEDs and includes versatile digital dimming via the I
2
C
input. The LTC3577-3/LTC3577-4 are designed to support
the SiRF Atlas IV processor and has pushbutton timing
and sequencing different from other LTC3577 versions.
The LTC3577-3/LTC3577-4 are available in a low profile
4mm
×
7mm
×
0.75mm 44-pin QFN package.
L,
LT, LTC, LTM, Linear Technology and the Linear logo 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, 7511390, 5481178, 6580258. Other
patents pending.
Full Featured Li-Ion/Polymer Charger/PowerPath™
Control with Instant-On Operation
Triple Adjustable High Efficiency Step-Down
Switching Regulators (800mA, 500mA, 500mA I
OUT
)
I
2
C Adjustable SW Slew Rates for EMI Reduction
High Temperature Battery Voltage Reduction
Improves Safety and Reliability
Overvoltage Protection Controller for USB (V
BUS
)/Wall
Inputs Provide Protection to 30V
Integrated 40V Series LED Back Light Driver with 60dB
Brightness Control and Gradation via I
2
C
1.5A Maximum Charge Current with Thermal Limiting
Battery Float Voltage: 4.2V (LTC3577-3)
4.1V (LTC3577-4)
Pushbutton ON/OFF Control with System Reset
Dual 150mA Current Limited LDOs
Start-Up Timing Compatible with SiRF Atlas IV
Processor
Small 4mm
×
7mm 44-pin QFN package
APPLICATIONS
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PNDs, DMB/DVB-H, Digital/Satellite Radio,
Media Players
Portable Industrial/Medical Products
Other USB-Based Handheld Products
TYPICAL APPLICATION
5V
ADAPTER
USB
10-LED Driver Efficiency
OPTIONAL
100mA/500mA
1000mA
V
OUT
CC/CV
CHARGER
LTC3577-3/LTC3577-4
2
I
2
C PORT
NTC
EFFICIENCY (%)
OVERVOLTAGE
PROTECTION
CHARGE
0V
90
80
70
60
MAX PWM
50
40
30
20
10
0
1.E-06
1.E-05
1.E-04 1.E-03 1.E-02
LED CURRENT (A)
1.E-01
CONSTANT
CURRENT
+
SINGLE CELL
Li-Ion
0.8V to 3.6V/150mA
0.8V to 3.6V/150mA
4 TO 10 LED
BOOST
0.8V to 3.6V/800mA
0.8V to 3.6V/500mA
0.8V to 3.6V/500mA
DUAL LDO
REGULATORS
LED BACKLIGHT WITH DIGITALLY
CONTROLLED DIMMING
PUSHBUTTON
CONTROL
TRIPLE HIGH
EFFICIENCY
STEP-DOWN
SWITCHING
REGULATORS
PB
357734 TA01a
357734 TA01b
357734fa
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LTC3577-3/LTC3577-4
TABLE OF CONTENTS
FEATURES....................................................................................................................................................................1
APPLICATIONS ............................................................................................................................................................1
TYPICAL APPLICATION ................................................................................................................................................1
DESCRIPTION ..............................................................................................................................................................1
ABSOLUTE MAXIMUM RATINGS .................................................................................................................................3
ORDER INFORMATION ................................................................................................................................................3
PIN CONFIGURATION ..................................................................................................................................................3
ELECTRICAL CHARACTERISTICS ................................................................................................................................4
TYPICAL PERFORMANCE CHARACTERISTICS ..........................................................................................................10
PIN FUNCTIONS.........................................................................................................................................................16
BLOCK DIAGRAM ......................................................................................................................................................19
OPERATION ...............................................................................................................................................................20
PowerPath OPERATION .........................................................................................................................................20
LOW DROPOUT LINEAR REGULATOR OPERATION...............................................................................................29
STEP-DOWN SWITCHING REGULATOR OPERATION ............................................................................................30
LED BACKLIGHT/BOOST OPERATION ...................................................................................................................34
I
2
C OPERATION .....................................................................................................................................................37
PUSHBUTTON INTERFACE OPERATION ................................................................................................................43
LAYOUT AND THERMAL CONSIDERATIONS .........................................................................................................47
TYPICAL APPLICATION ..............................................................................................................................................49
PACKAGE DESCRIPTION ............................................................................................................................................51
RELATED PARTS ........................................................................................................................................................52
357734fa
2
LTC3577-3/LTC3577-4
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2, 3)
PIN CONFIGURATION
TOP VIEW
44
CHRG
43 CLPROG
42
EXTPWR
41
ACPR
40 V
BUS
39 V
OUT
38 BAT
I
LIM0
1
I
LIM1
2
LED_FS 3
WALL 4
SW3 5
V
IN3
6
FB3 7
OVSENS 8
LED_OV 9
DV
CC
10
SDA 11
SCL 12
OVGATE 13
PWR_ON 14
ON
15
45
37 IDGATE
36 PROG
35 NTC
34 NTCBIAS
33 SW1
32 V
IN12
31 SW2
30 V
INLD02
29 LDO2
28 LDO1
27 V
INLDO1
26 FB1
25 FB2
24 LDO2_FB
23 LDO1_FB
UFF PACKAGE
44-LEAD (7mm 4mm) PLASTIC QFN
T
JMAX
= 110°C,
θ
JA
= 45°C/W
EXPOSED PAD (PIN 45) IS GND, MUST BE SOLDERED TO PCB
V
SW
............................................................ –0.3V to 45V
V
BUS
, V
OUT
, V
IN12
, V
IN3
, V
INLDO1
, V
INLDO2
, WALL
t < 1ms and Duty Cycle < 1% .................. –0.3V to 7V
Steady State............................................. –0.3V to 6V
CHRG,
BAT, LED_FS, LED_OV,
PWR_ON,
EXTPWR,
PBSTAT, PGOOD,
FB1, FB2, FB3, LDO1, LDO1_FB, LDO2,
LDO2_FB, DV
CC
, SCL, SDA, EN3.................. –0.3V to 6V
NTC, PROG, CLPROG,
ON,
I
LIM0
, I
LIM1
(Note 4)............................................–0.3V to V
CC
+ 0.3V
I
VBUS
, I
VOUT
, I
BAT
.........................................................2A
I
SW3
(Continuous) ................................................850mA
I
SW2
, I
SW1
(Continuous) .......................................600mA
I
LDO1
, I
LDO2
(Continuous).....................................200mA
I
CHRG
, I
ACPR
, I
EXTPWR
, I
PBSTAT
, I
PGOOD
....................75mA
I
OVSENS
...................................................................10mA
I
CLPROG
, I
PROG
, I
LED_FS
, I
LED_OV
...............................2mA
Maximum Junction Temperature........................... 110°C
Operating Temperature Range.................. –40°C to 85°C
Storage Temperature Range................... –65°C to 125°C
ORDER INFORMATION
LEAD FREE FINISH
LTC3577EUFF-3#PBF
LTC3577EUFF-4#PBF
TAPE AND REEL
LTC3577EUFF-3#TRPBF
LTC3577EUFF-4#TRPBF
PART MARKING
35773
35774
PACKAGE DESCRIPTION
44-Lead (4mm
×
7mm) Plastic QFN
44-Lead (4mm
×
7mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
–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/
PBSTAT 16
EN3 17
SW 18
SW 19
SW 20
PGOOD 21
I
LED
22
357734fa
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LTC3577-3/LTC3577-4
ELECTRICAL CHARACTERISTICS
SYMBOL
V
BUS
I
BUS_LIM
PARAMETER
Input Supply Voltage
Total Input Current (Note 5)
I
LIM0
= 5V, I
LIM1
= 5V (1x Mode)
I
LIM0
= 0V, I
LIM1
= 0V (5x Mode)
I
LIM0
= 0V, I
LIM1
= 5V (10x Mode)
1x, 5x, 10x Modes
I
LIM0
= 5V, I
LIM1
= 0V (Suspend Mode)
l
l
l
Power Manager
. The
l
denotes the specifications which apply over the
MIN
4.35
80
450
900
90
475
950
0.42
0.05
1000
TYP
MAX
5.5
100
500
1000
0.1
UNITS
V
mA
mA
mA
mA
mA
mA/mA
V
V
V
3.9
100
V
V
mV
mV
mΩ
full operating temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, V
BAT
= 3.8V, I
LIM0
= I
LIM1
= 5V, WALL = 0V,
V
INLDO2
= V
INLOD1
= V
IN12
= V
IN3
= V
OUT
, R
PROG
= 2k, R
CLPROG
= 2.1k, unless otherwise noted.
CONDITIONS
Input Power Supply
I
BUSQ
h
CLPROG
V
CLPROG
Input Quiescent Current, POFF State
Ratio of Measured V
BUS
Current to
CLPROG Program Current
CLPROG Servo Voltage in Current
Limit
V
BUS
Undervoltage Lockout
1x Mode
5x Mode
10x Mode
Rising Threshold
Falling Threshold
3.5
0.2
1.0
2.0
3.8
3.7
50
–50
200
V
UVLO
V
DUVLO
R
ON_ILIM
Battery Charger
V
FLOAT
V
BUS
to V
OUT
Differential Undervoltage Rising Threshold
Lockout
Falling Threshold
Input Current Limit Power FET On-
Resistance (Between V
BUS
and V
OUT
)
V
BAT
Regulated Output Voltage
LTC3577-3
LTC3577-3, 0 ≤ T
A
≤ 85°C
LTC3577-4
LTC3577-4, 0 ≤ T
A
≤ 85°C
4.179
4.165
4.079
4.065
l
l
l
4.200
4.200
4.1
4.1
1000
500
200
6
55
130
1.000
0.100
1000
4.221
4.235
4.121
4.135
1050
535
220
27
100
200
V
V
V
V
mA
mA
mA
μA
μA
μA
V
V
mA/mA
I
CHG
Constant-Current Mode Charge Current R
PROG
= 1k, Input Current Limit = 2A
IC Not in Thermal Limit
R
PROG
= 2k, Input Current Limit = 1A
R
PROG
= 5k, Input Current Limit = 0.4A
Battery Drain Current, POFF State,
Buck3 Disabled, No Load (Note 15)
Battery Drain Current, PON State,
Buck3 Enabled (Notes 10, 15)
PROG Pin Servo Voltage
PROG Pin Servo Voltage in Trickle
Charge
Ratio of I
BAT
to PROG Pin Current
Trickle Charge Current
Trickle Charge Rising Threshold
Trickle Charge Falling Threshold
Recharge Battery Threshold Voltage
Safety Timer Termination Period
Bad Battery Termination Time
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
V
BAT
= 4.3V, Charger Time Out
V
BUS
= 0V
V
BUS
= 0V, I
OUT
= 0μA, No Load On
Supplies, Burst Mode Operation
V
BAT
> V
TRKL
V
BAT
< V
TRKL
950
465
180
I
BATQ_OFF
I
BATQ_ON
V
PROG,CHG
V
PROG,TRKL
h
PROG
I
TRKL
V
TRKL
ΔV
RECHRG
t
TERM
t
BADBAT
h
C/10
R
ON_CHG
T
LIM
40
2.5
–75
3.2
0.4
0.085
50
2.9
2.75
–100
4
0.5
0.1
200
110
60
3.0
–125
4.8
0.6
0.11
mA
V
V
mV
Hour
Hour
mA/mA
mΩ
°C
End-of-Charge Indication Current Ratio (Note 6)
357734fa
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LTC3577-3/LTC3577-4
full operating temperature range, otherwise specifications are at T
A
= 25°C. V
BUS
= 5V, V
BAT
= 3.8V, I
LIM0
= I
LIM1
= 5V, WALL = 0V,
V
INLDO2
= V
INLOD1
= V
IN12
= V
IN3
= V
OUT
, R
PROG
= 2k, R
CLPROG
= 2.1k, unless otherwise noted.
SYMBOL
V
COLD
V
HOT
V
TOO
_
HOT
I
NTC
I
BAT2HOT
V
BAT2HOT
Ideal Diode
V
FWD
R
DROPOUT
I
MAX
V
OVCUTOFF
V
OVGATE
I
OVSENSQ
t
RISE
V
ACPR
V
W
ΔV
W
I
QWALL
Forward Voltage Detection
Diode On-Resistance, Dropout
Diode Current Limit
Overvoltage Protection Threshold
OVGATE Output Voltage
OVSENS Quiescent Current
OVGATE Time to Reach Regulation
ACPR
Pin Output High Voltage
ACPR
Pin Output Low Voltage
Absolute Wall Input Threshold Voltage
Differential Wall Input Threshold
Voltage
Wall Operating Quiescent Current
I
OUT
= 10mA
I
OUT
= 200mA
(Note 7)
Rising Threshold, R
OVSENS
= 6.2k
Input Below V
OVCUTOFF
Input Above V
OVCUTOFF
V
OVSENS
= 5V
C
OVGATE
= 1nF
I
ACPR
= 0.1mA
I
ACPR
= 1mA
V
WALL
Rising
V
WALL
Falling
V
WALL
– V
BAT
Falling
V
WALL
– V
BAT
Rising
I
WALL
+ I
VOUT
, I
BAT
= 0mA,
WALL = V
OUT
= 5V
I
LIM0
, I
LIM1
I
LIM0
, I
LIM1
I
LIM0
, I
LIM1
; V
PIN
= 1V
I
CHRG
= 10mA
V
BAT
= 4.5V, V
CHRG
= 5V
1.2
2
0.15
0
0.4
1
V
OUT
– 0.3
6.10
5
15
200
3.6
6.35
1.88 • V
OVSENS
0
40
2.5
V
OUT
0
4.3
3.2
25
75
440
6.70
12
25
mV
mΩ
A
V
V
V
μA
ms
V
V
V
V
mV
mV
μA
PARAMETER
Cold Temperature Fault Threshold
Voltage
Hot Temperature Fault Threshold
Voltage
NTC Discharge Threshold Voltage
NTC Leakage Current
BAT Discharge Current
BAT Discharge Threshold
CONDITIONS
Rising NTC Voltage
Hysteresis
Falling NTC Voltage
Hysteresis
Falling NTC Voltage
Hysteresis
V
NTC
= V
BUS
= 5V
V
BAT
= 4.1V, NTC < V
TOO_HOT
I
BAT
< 0.1mA, NTC < V
TOO_HOT
MIN
75
34
24.5
–50
170
3.9
TYP
76
1.3
35
1.3
25.5
50
MAX
77
36
26.5
50
UNITS
%V
NTCBIAS
%V
NTCBIAS
%V
NTCBIAS
%V
NTCBIAS
%V
NTCBIAS
mV
nA
mA
V
NTC, Battery Discharge Protection
ELECTRICAL CHARACTERISTICS
Power Manager
. The
l
denotes the specifications which apply over the
Overvoltage Protection
Wall Adapter and High Voltage Buck Output Control
0.3
4.45
3.1
0
100
Logic (I
LIM0
, I
LIM1
and
CHRG)
V
IL
V
IH
I
PD
V
CHRG
I
CHRG
Input Low Voltage
Input High Voltage
Static Pull-Down Current
CHRG
Pin Output Low Voltage
CHRG
Pin Input Current
0.4
V
V
μA
V
μA
357734fa
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