The MAX17005B/MAX17006B/MAX17015B are high-frequency
multichemistry battery chargers. These circuits
feature a new high-frequency current-mode architecture
that significantly reduces component size and cost*.
The charger uses a high-side MOSFET with n-channel
synchronous rectifier. Widely adjustable charge current,
charge voltage, and input current limit simplify the construction
of highly accurate and efficient chargers.
The charge voltage and charge current are set with
analog control inputs. The charge current setting can
also be adjusted with a PWM input. High-accuracy current-
sense amplifiers provide fast cycle-by-cycle current-
mode control to protect against short circuits to the
battery and respond quickly to system load transients.
In addition, the charger provides a high-accuracy analog
output that is proportional to the adapter current. In
the MAX17015B, this current monitor remains active
when the adapter is absent to monitor battery discharge
current.
The MAX17005B charges three or four Li+ series cells,
and the MAX17006B charges two or three Li+ series
cells. The MAX17015B adjusts the charge voltage setting
and the number of cells through a feedback resistor-
divider from the output. All variants of the charger
can provide at least 4A of charge current with a 10mΩ
sense resistor.
The charger utilizes a charge pump to control an n-channel
adapter selection switch. The charge pump remains
active even when the charger is off. When the adapter
is absent, a p-channel MOSFET selects the battery.
The MAX17005B/MAX17006B/MAX17015B are available
in a small, 4mm x 4mm x 0.8mm 20-pin, lead-free
TQFN package. An evaluation kit is available to reduce
design time.
Applications
Notebook Computers
Tablet PCs
Portable Equipment with Rechargeable Batteries