POWER EV BATTERY
MANAGEMENT
The wireless MCU offers
dedicated time slots that provide high
throughput and low latency to protect
data from loss or corruption while
enabling multiple battery cells to send
voltage and temperature data to the
main MCU with, according to TI, a
±2-mV accuracy and a network packet
error rate of less than 10-7.
TI’s wireless BMS functional safety
concept addresses communication
error detection and security.
The proprietary protocol via the
CC2662R-Q1 wireless MCU has
been designed to enable a robust
and scalable data exchange between
a host system processor and the
BQ79616-Q1 battery monitor and
balancer.
According to TI the wireless
protocol for BMS via the CC2662R-Q1
is able to offer the industry’s highest
network availability of greater than
99.999% and a network restart of
300-ms maximum availability.
“The car chassis acts as a Faraday
cage,” explains Ram Vedantham,
manager of TI’s 2.4Ghz Business
Line,” so, as a consequence, any
interference is contained within
the systems. Careful design of the
protocol, which has combined timedivision
multiplexing with frequency
hopping, means that we’ve been
able to eliminate any noise to the
maximum extent possible.”
Moving to production faster
Auto manufacturers will be able to
advance to production much faster
using this wireless BMS offering,
as TI has also made available the
SimpleLink 2.4-GHz CC2662R-Q1
wireless microcontroller
(MCU) evaluation module,
software and functional
safety enablers such
as a safety manual;
failure mode and effects
analysis (FMEA); as well
as diagnostic analysis
(FMEDA).
Security is a key
requirement when
it comes to wireless devices, so to
mitigate potential threats TI is making
available security enablers such
as key exchange and refreshment;
unique device authentication; debug
security; software IP protection with
a joint test action group (JTAG) lock;
Advanced Encryption Standard (AES)
128-bit cryptographic acceleration
and message integrity checks
Anticipating automakers’ longterm
design needs, TI says that its
wireless BMS has been designed to
be scalable. Automakers will be able
to create a battery module using a
single wireless system-on-chip that’s
connected with multiple BQ79616-Q1
battery monitors making it possible to
deliver different con gurations such
as 32-, 48- and 60-cell systems.
The system is designed to support
up to 100 nodes with low latency of
less than 2 ms per node and timesynchronized
measurements across
every node.
The CC2662R-Q1 wireless MCU
isolates individual cell monitoring
units, eliminating the need for
and cost of daisy-chain isolation
components, which is the case with
existing solutions.
The BQ79616-Q1 battery monitor
and balancer is able to offer different
channel options in the same package
type, providing pin-to-pin compatibility
and supporting 100% reuse of the
established software and hardware
across any platform.
“This move to a wireless BMS
“EVs are packed
with battery
cells and multi
cabling, so in
every EV the BMS
is an essential
component.”
Karl-Heinz
Steinmetz
Below: TI’s wireless
solution combines
two chips: the
CC2662R-Q1 wireless
MCU and the
BQ79616-Q1 battery
monitor
solution demonstrates how vehicle
designers will be able to remove
heavy, expensive, maintenanceprone
cabling and improve
the reliability and ef ciency
of EVs worldwide,” explains
Steinmetz.
“It provides much greater
exibility to scale designs across
production models and
by removing all these
components there’s plenty of
scope for designers to add
more intelligence or more
battery cells.”
“Today these devices are wired
manually so by going wireless
it’s possible to signi cantly cut
manufacturing costs – there are
no complex wiring systems and we
no longer need a wiring harness,
connectors, transformers or
capacitors.
“These advancements provide
much greater exibility of design
while also lowering the cost, relative
to traditional systems. This is a
solution that not only combines these
technical advantages but does so
with ASIL-D compliance.”
Naturally there are concerns
with wireless BMS, as they need
to be able to monitor accurately in
real time. Not only do they need to
be accurate but need to transmit
data rapidly and with low error
rates – made all the more dif cult
by operating in a hot and noisy
environment.
“Monitoring the battery is critical
as is measuring the voltage and
temperature if you are to guarantee
that the maximum energy is being
extracted between charges. This
new family of devices ensure that
its possible to measure these
parameters with great accuracy,” said
Ivo Marocco, director of business
development and functional safety for
Battery Automotive products at TI.
TI’s wireless solution, includes
a proprietary wireless protocol, that
looks to address these challenges
and combines two new chips, the
CC266C2R0QI wireless MCU and the
BQ79616-Q1 battery monitor and
balancer.
www.newelectronics.co.uk 9 February 2021 21
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