managed with a programmable resistor,
and single- and two-cell LiFePO 4 batteries
can be charged with the MCP738123/213
linear chargers. Most of the controllers are
available with thermal regulation, reverse
discharge protection, a safety charge tim-
er, and integrated current sensing.
Solutions like the MCP73830 battery
charger need to offer features support-
ing long life, long runtime, and fast
charging, such as battery pre-condition-
ing, programmable charge currents, and
end-of-charge thresholds. These features
maximize battery capacity, minimize
charge time, and extend battery life in
the low-component-count, small-area
circuits used in portable applications.
For many portable devices, wireless
charging is becoming a cost-effective
alternative to cables, which also allow
device packaging to be seamless without a
charger socket. An example of this kind of
solution is the Power by Linear LTC4126
from Analog Devices Inc. The LTC4126
provides a wireless charger for Li-ion cells
with a high-efficiency multi-mode charge
pump DC/DC converter that provides a
regulated 1.2-V output at up to 60 mA.
The LTC4126’s 1.2-V charge pump out-
put offers pushbutton on/off control and
can directly power the supported product’s
ASIC, greatly simplifying the system and
reducing the number of external compo-
nents. The device is suited for space-con-
strained low-power Li-ion–powered
wearables like hearing aids, medical smart
patches, and other IoT products.
The device offers input power
management circuitry to rectify AC
power from a wireless power receiver
coil, managing a 2.7-V to 5.5-V input
rail to power a constant-current/con-
stant-voltage battery charger. Fea-
tures include a pin-selectable charge
voltage of 4.2 V or 4.35 V, 7.5-mA
charge current, automatic recharge,
battery temperature monitoring via
an NTC pin, and an onboard 6-hour
safety charge termination timer. There is
also low-battery protection that discon-
nects the battery from all loads when the
voltage drops below 3.0 V. In addition,
the charge pump switching frequency is
50 kHz/75 kHz to keep switching noise
out of the audible range, useful in au-dio-related applications such as hearing
aids and wireless headsets.Out of the box
Most products that we think of as external
chargers are AC/DC power supplies that
feed an internal battery-management
PMIC. One of the most popular external
power sources for DC-driven devices is
the USB port. Some USB systems take
wall current and turn it into the 5-Vdc
output provided, and some are intended
for internal use in a larger system with a
higher-voltage internal DC bus.
An example of a DC/DC USB power
supply intended for use as an internal
subsystem in a vehicle can be found in
Molex’s USB modules, which deliver 5 V
at 1.5 A and can be deployed at multiple
in-vehicle locations (Fig. 2). These mod-
ules also enable the integration of mul-
tiple I/O port connection types such as
USB, HDMI, Ethernet, SD memory cards,
auxiliary jack
inputs, andmore to meet end-system requirements in
either active or passive designs.
The pre-assembled active USB charger
is compliant with Battery Charging 1.2
standards and is designed to fit in existing
rocker-switch panels in vehicles to facilitate
drop-in design. The products are tested for
electrical, mechanical, environmental, elec-
tromagnetic interference (EMI), electro-
static discharge (ESD), and signal integrity.
These products save time and money with
full turn-key testing and product valida-
tion. Compatible with most in-vehicle
12-V power distribution architectures, the
modules provide a relatively simple way to
integrate USB and other portable-device
I/O and power interfaces into a vehicle.
When it comes to EVs, there is more
to the space than just cars. There are a lot
of smaller EVs used in industrial facili-
ties and outdoor applications. To serve
applications like these, the RC1000 from
Delta-Q Technologies, as an example,
is a high-frequency charging solution
capable of charging both lead-acid and
Li-ion batteries (Fig. 3). The new charger
also offers controller area network (CAN
bus) communications, such as CANopen
and SAE J1939, for seamless machine
integration.
Designed with original equipment
manufacturers in mind, the RC1000 is
suitable for use in applications such as
battery-powered floor care machines,
outdoor power equipment, and utility
vehicles. Similar to its family series, the
RC1000 has an IP66-rated ingress
protection to seal out dirt and
fluids, while its mechanical design
and component selection resist
vibration, shock, and temperature
extremes.Looking ahead
Battery-driven systems will contin-
ue to expand and develop as a core
technology enabling our digitally
empowered cloud-enabled future. These
advanced batteries will always require
sophisticated charging and manage-
ment systems to provide optimum value
to the user. Selecting the best charging
solution for your design will pay off in
major performance and reliability gains
in your products. ☐32 PRODUCT ROUNDUP Batteries
IMAGE: (TOP) MOLEX; (BOTTOM) DELTA-Q
Fig. 2: Molex’s USB modules can be deployed
at multiple in-vehicle locations.Fig. 3: The
RC1000 from
Delta-Q is a high frequency charging
solution capable of charging both lead-acid
and Li-ion batteries.
JANUARY 2019 • electronicproducts.com • ELECTRONIC PRODUCTS