Linear Technology's LTC 6803 is a second generation high
voltage battery monitor for hybrid/electric vehicle (HEVs), electric vehicles
(EVs) and other high voltage, high performance battery systems. The LTC6803 is
a complete battery measuring IC that includes a 12-bit ADC, a precision voltage
reference, a high voltage input multiplexer and a serial interface. Each
LTC6803 can measure up to 12 individual battery cells in series. The device's
proprietary design enables multiple LTC6803s to be stacked in series without
optocouplers or isolators, permitting precision voltage monitoring of every
cell in long strings of series-connected batteries. The LTC6803 follows the
LTC6802 with the same functionality and pinout, plus a number of significant
The maximum total measurement
error of the LTC6803 is guaranteed to be less than 0.25 percent from -40 to
125C. The LTC6803 offers an extended cell measurement range from -300mV to 5V,
enabling the LTC6803 to monitor a wide range of battery chemistries, as well as
supercapacitors. Each cell is monitored for undervoltage and overvoltage
conditions, and an associated MOSFET is available to discharge overcharged
cells. Added functionality is provided by an onboard 5V regulator, temperature
sensor, GPIO lines and thermistor inputs.
For long-term battery pack
storage, the current consumed by the integrated BMS can potentially unbalance
the cells. The LTC6803 addresses this concern with a standby mode that draws
less than 12uA. The power input of the LTC6803 is isolated from the stack,
allowing the LTC6803 to draw current from an independent source. When powering
from this input, the current draw on the pack is reduced to less than 1ÂµA.
The first Tacoma Narrows Bridge was a Washington State suspension bridge that opened in 1940 and spanned the Tacoma Narrows strait of Puget Sound between Tacoma and the Kitsap Peninsula. It opened to traffic on July 1, 1940, and dramatically collapsed into Puget Sound on November 7, just four months after it opened.
Noting that we now live in an era of “confusion and ill-conceived stuff,” Ammunition design studio founder Robert Brunner, speaking at Gigaom Roadmap, said that by adding connectivity to everything and its mother, we aren't necessarily doing ourselves any favors, with many ‘things’ just fine in their unconnected state.
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