LTC3577-3 AND LTC3577-4
1
DESCRIPTION
WARNING!
Do not look directly at operating LED.
This circuit produces light that can damage eyes.
Demo Circuit 1592A is a Highly Integrated Portable
Product PMIC with a pushbutton controller, two LDOs,
three buck converters, a Li-Ion battery charger, and a
power path controller featuring the LTC3577-3 and
LTC3577-4. This board utilizes a DC590B, USB to I
2
C
interface board, to control the LTC3577-3/LTC377-4
software control window.
The LTC3577-3 and LTC3577-4 are PowerPath™ man-
ager with automatic load prioritization, battery charger,
Bat-Track™ controller, push button controlled power up
sequence and reset, and a 10 LED string controller with
gradation and PWM control. The three buck regulators
and the LED Boost controller have adjustable slew rates
for EMI reduction.
The LTC3577-3 and LTC3577-4 has a high temperature
battery voltage reduction feature that reduces the battery
voltage under high temperature conditions to improve
safety and reliability.
Refer to the LTC3577-3 and LTC3577-4 datasheet for
more details on the electrical and timing specifications.
Design files for this circuit board are available. Call
the LTC factory.
L
, LTC, LTM, LT are registered trademarks of Linear Technology Corporation. PowerPath
and Bat-Track are trademarks of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
PERFORMANCE SUMMARY
Specifications are at T
A
= 25°C
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
Input Supply Range (V
BUS
)
4.35 5.5
V
Absolute Wall Input Threshold (V
W
) V
WALL
Rising
V
WALL
Falling
3.1
4.3
3.2
4.45
V
V
DV
CC
Operating Voltage
1.6
5.5
V
DV
CC
UVLO (V
DVCC,UVLO)
1
V
V
BAT
Regulated Output Voltage (V
FLOAT
) DC1592A-A
(LTC3577-3)
DC1592A-B (LTC3577-4)
4.179
4.079
4.200
4.100
4.221
4.121
V
V
Constant Current Mode Charge Current (I
CHRG
) R
PROG
= 2K
Ω
, Input current limit = 1A
465
500
535
mA
V
OUT
UVLO
V
OUT
Falling
V
OUT
Rising
2.5 2.7
2.8
2.9
V
V
V
OUT1
0 to 500mA
1.8
V
V
OUT2
0 to 500mA
3.3
V
V
OUT3
0 to 800mA
1.2
V
LDO1
0 to 150mA
3.3
V
LDO2
0 to 150mA
1.2
V
Full-Scale LED Current
20
mA
Demo Circuit 1592A-A/-B
QUICK START GUIDE
LTC3577-3 and LTC3577-4
Highly Integrated Portable
Product PMIC
