Document
LTC3554/LTC3554-1/ LTC3554-2/LTC3554-3
Features
Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators
Description
n 10μA Standby Mode Quiescent Current (All Outputs On) n Seamless Transition Between Input Power Sources:
Li-Ion/Polymer Battery and USB n 240mΩ Internal Ideal Diode n Dual High Efficiency Step-Down Switching Regulators
(200mA IOUT) with Adjustable Output Voltages n Pushbutton On/Off Control with System Reset n Reset Time: 5 sec (LTC3554/LTC3554-1), 14 sec (LTC3554-2/LTC3554-3) n Full Featured Li-Ion/Polymer Battery Charger n Programmable Charge Current with Thermal Limiting n Instant-On Operation with Discharged Battery n Battery Float Voltage: 4.2V (LTC3554/LTC3554-2/
LTC3554-3), 4.1V (LTC3554-1) n 3mm × 3mm × 0.75mm 20-Lead QFN Package
Applications
n USB-Based Handheld Products n Portable Li-Ion/Polymer Based Electronic Devices n Fitness Computers n Low Power Medical Devices
The LTC®3554 family* are micropower, highly integrated power management and battery charger ICs for single-cell Li-Ion/Polymer battery applications. They include a PowerPath™ manager with automatic load prioritization, a battery charger, an ideal diode and numerous internal protection features. Designed specifically for USB applications, the LTC3554 power managers automatically limit 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 family are available in a 3mm × 3mm × 0.75mm 20-lead QFN package.
L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and PowerPath, Hot Swap and Bat-Track are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6522118, 6700364, 5481178, 6304066, 6570372, 6580258, 7511390. *See table on page 2 for available options.
Typical Application
4.35V TO 5.5V USB INPUT
100k
10µF
100k T 1.87k
VBUS
VOUT
NTC LTC3554 CHRG
PROG
BAT
10µF
+ Li-Ion
BATTERY
ON/OFF
HPWR SUSP
PWR_ON1
FSEL STBY PGOOD PWR_ON2 PBSTAT ON
BVIN
SW1 FB1
2.2µF 4.7µH
10pF
SW2
FB2
3554 TA01a
10µH 10pF
2.05M 649k
332k 649k
SYSTEM LOAD
3.3V 200mA 10µF 1.2V 200mA 10µF
BATTERY DRAIN CURRENT (µA)
Battery Drain Current vs Temperature
14 VBAT = 3.8V
12
STBY = 3.8V REGULATORS LOAD = 0mA
10
BOTH REGULATORS ENABLED
8 ONE REGULATOR ENABLED
6 4 BOTH REGULATORS DISABLED
2
HARD RESET 0 –75 –50 –25 0 25 50 75
TEMPERATURE (°C)
100 125
3554 TA01b
3554123ff
1
LTC3554/LTC3554-1/ LTC3554-2/LTC3554-3
Absolute Maximum Ratings
(Notes 1, 2, 3)
VBUS, VOUT, 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 VCC + 0.3V IBAT.............................................................................. 1A ISW1, ISW2 (Continuous)....................................... 300mA ICHRG, IPGOOD, IPBSTAT.............................................75mA Operating Junction Temperature Range....–40°C to 85°C Junction Temperature.............................................110°C Storage Temperature Range................... –65°C to 125°C
Pin Configuration
TOP VIEW
VBUS SUSP VOUT BAT PROG
HPWR FSEL
PBSTAT PGOOD
ON
20 19 18 17 16 1 15 NTC
2 14 CHRG
3
21 GND
13 SW1
4 12 BVIN
5 11 SW2 6 7 8 9 10
FB1 FB2 PWR_ON2 PWR_ON1 STBY
UD PACKAGE 20-LEAD (3mm × 3mm) PLASTIC QFN
TJMAX = 110°C, θJA = 58.7°C/W EXPOSED PAD (PIN 21) IS GND, AND MUST BE SOLDERED TO PCB GND
Order Information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
LTC3554EUD#PBF LTC3554EUD-1#PBF
LTC3554EUD#TRPBF LTC3554EUD-1#TRPBF
LDYS LGFG
20-Lead (3mm × 3mm) Plastic QFN 20-Lead (3mm × 3mm) Plastic QFN
LTC3554EUD-2#PBF
LTC3554EUD-2#TRPBF LFZX
20-Lead (3mm × 3mm) Plastic QFN
LTC3554EUD-3#PBF LTC3554EPD#PBF
LTC3554EUD-3#TRPBF LTC3554EPD#TRPBF
LGHK FDPT
20-Lead (3mm × 3mm) Plastic QFN 20-Lead (3mm × 3mm) Plastic UTQFN
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/
TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C –40°C to 85°C –40°C to 85°C –40°C to 85°C (OBSOLETE)
LTC3554 Options
FLOAT PART NUMBER VOLTAGE
LTC3554
4.2V
LTC3554-1
4.1V
LTC3554-2
4..