LTC4090-3_15 Datasheet, PDF (1/30 Pages) Linear Technology – USB Power Manager with 2A High Voltage Bat-Track Buck Regulator

FEATURES
nn _{Seamless Transition Between Power Sources:}
Li-Ion Battery, USB, and 6V to 36V Supply (60V Max)
nn _{2A Output High Voltage Buck Regulator with}
Bat-Track™ Adaptive Output Control
nn _{3.95V Float Voltage Improves Battery Life Span and}
High Temperature Safety Margin
nn _{Internal 215mΩ Ideal Diode Plus Optional External}
Ideal Diode Controller Provides Low Loss
PowerPath™ When External Supply/ USB Not Present
nn _{Load Dependent Charging from USB Input Guaran-}
tees Current Compliance
nn _{Full Featured Li-Ion Battery Charger}
nn _{1.5A Maximum Charge Current with Thermal Limiting}
nn _{NTC Thermistor Input for Temperature Qualified}
Charging
nn _{Tiny (3mm × 6mm × 0.75mm) 22-Pin DFN Package}
APPLICATIONS
nn _{Embedded Automotive Accessories}
nn _{Personal Navigation Devices}
nn _{Other USB-Based Handheld Products}
LTC4090-3
USB Power Manager with
2A High Voltage Bat-Track
Buck Regulator
DESCRIPTION
The LTC^®4090-3 is a USB power manager plus high voltage
Li-Ion/Polymer battery charger. The device controls the
total current used by the USB peripheral for operation and
battery charging. Battery charge current is automatically
reduced such that the sum of the load current and the
charge current does not exceed the programmed input
current limit. The LTC4090-3 also accommodates high
voltage power supplies, such as 12V AC/DC wall adapters,
Firewire, or automotive power.
The LTC4090 provides a Bat-Track adaptive output that
tracks the battery voltage for high efficiency charging
from the high voltage input. This 3.95V version of the
standard LTC4090 is intended for applications which
have extended battery lifetime requirements or those that
require high temperature (>60°C) operation or storage
under these conditions. A reduced float voltage will trade
off initial cell capacity for the benefit of increased capacity
retention over the life of the battery. The charge current is
programmable and an end-of-charge status output (CHRG)
indicates full charge.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and Bat-Track, PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners.
TYPICAL APPLICATION
HIGH (7.5V-36V)
VOLTAGE INPUT
5V WALL
ADAPTER
USB
59k
270pF
HVIN
1µF
IN
4.7µF
V_C
TIMER
BOOST
0.47µF
SW
LTC4090-3
HVOUT
HVPR
OUT
BAT
6.8µH
22µF
1k
LOAD
4.7µF
0.1µF
RT
CLPROG
40.2k
2k
GND PROG
100k ⁺
Li-Ion BATTERY
V_OUT (TYP)
V_BAT + 0.3V
5V
V_BAT
AVAILABLE INPUT
HV INPUT
USB ONLY
BAT ONLY
40903 TAO1
For more information www.linear.com/LTC4090-3
LTC4090-3 High Voltage Battery
Charger Efficiency
90 _{FIGURE 12 SCHEMATIC}
80
WITH R_PROG = 52k
NO OUTPUT LOAD
70
60
50
40
HVIN = 8V
30
HVIN = 12V
HVIN = 24V
HVIN = 36V
20
2.0
2.5
3.0
3.5
4.0
4.5
V_BAT (V)
40903 TA01b
40903fb
1