ltm8062 Linear Technology Corporation, ltm8062 Datasheet - Page 8

• Manufacturer Part Number: ltm8062
• Description: Ltm8062 32vin, 2a ?module Power Tracking Battery Charger Features
• Manufacturer: Linear Technology Corporation

LTM8062
BLOCK DIAGRAM
OPERATION
The LTM8062 is a complete monolithic, mid-power, power
tracking battery charger, addressing high input voltage ap-
plications with solutions that use a minimum of external
components. The product can be programmed for float
voltages between 3.3V and 14.4V with just two external
resistors, operating under a 1MHz fixed frequency, average
current mode step-down architecture. A 2A power Schottky
diode is integrated within the μModule for reverse input
voltage protection. A wide input range allows the operation
to full charge from an input voltage up to 32V. A precision
threshold on the RUN pin allows the implementation of
a UVLO feature by using a simple resistor network. The
charger can also be put into a low current shutdown mode,
in which the input supply bias is reduced to only 15μA.
The LTM8062 employs an input voltage regulation loop,
which reduces charge current if a monitored input volt-
age falls below a programmed level. When the LTM8062
is powered by a solar panel, the input regulation loop
8
V
RUN
ADJ
TMR
NTC
INREG
V
0.1μF
INA
0.1μF
COMPENSATION
INTERNAL
GND
V
IN
MANAGEMENT
CONTROLLER
CURRENT
BATTERY
MODE
FAULT
is used to maintain the panel at peak output power. The
LTM8062 automatically enters a battery precondition mode
if the sensed battery voltage is very low. In this mode,
the charge current is reduced to 300mA. Once the bat-
tery voltage climbs above the internally set precondition
threshold (2.3V at the ADJ pin), the μModule automati-
cally increases the maximum charge current to the full
programmed value.
The LTM8062 can use a charge current based C/10 termina-
tion scheme, which ends a charge cycle when the battery
charge current falls to one-tenth the programmed charge
current. The LTM8062 also contains an internal charge cycle
control timer, for timer-based termination. When using the
internal timer, the charge cycle can continue beyond the
C/10 level to top-off the battery. The charge cycle terminates
when the programmed time elapses, about three hours for
a 0.68μF timer capacitor. The CHRG status pin continues
to signal charging at a C/10 or greater rate, regardless of
CHRG
8.2μH
RESISTOR
SENSE
10μF
BIAS
ADJ
BAT
8062 BD
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