AD8280(Lithium Ion Battery Safety Monitor) IntrocuctionThe AD8280 is a hardware-only safety monitor for lithium ion battery stacks. The part has inputs to monitor six battery cells and two temperature sensors (either NTC or PTC thermistors). The part is designed to be daisy-chained with other AD8280 devices, enabling the monitoring of a stack of significantly more than six cells without requiring numerous isolators. Users can configure its output for either an independent or shared alarm state.The AD8280 operates independently from a primary monitor and includes its own reference and LDO (Low Dropout Regulator), both powered entirely from the battery cell stack. The reference, in combination with external resistor dividers, establishes trip points for overvoltages and undervoltages. Each cell channel contains programmable deglitching circuitry to prevent alarms from transient input levels.Additionally, the AD8280 features two digital pins that users can utilize to select various combinations of inputs in cases where fewer than six cells are to be monitored. Most important, it has a self-test feature,making it suitable for high reliability applications, such as automotive hybrid electric vehicles or higher voltage industrial usage,such as uninterruptible power supplies. The AD8280 can function over a temperature range of -40°C to 105°C.FeatureWide supply voltage range: 6.0 V to 30.0 VMultiple inputs can monitor 3 to 6 cell voltages and 2 temperaturesAdjustable threshold levels: overvoltage, undervoltage,overtemperatureAlarm options: separate 0r shared alarmsExtended temperature range performance-40°C < TA< 105°CCan be daisy-chainedInternal referencePowered from battery stackLDO available to power isolatorQualified for automotive applicationsExtensive self-test feature aids in meeting ASIL/SIL requirementsAppearance
