Analog Devices Inc./Maxim Integrated

The MAX17851 SPI to UART safety monitoring bridge translates communication from SPI format to universal asynchronous receiver transmitter (UART) format specially designed to interface with Maxim's Battery Management Data Acquisition System. The safety monitoring bridge enables robust communication with baud rates extending up to 4Mbps in both single and dual daisy-chain system architectures. High throughput, dual UART systems can read 96 cells of battery voltages within 1173us.The UART is ISO26262 compliant for automotive safety integrity level (ASIL) D systems providing detection of message corruption, delay, loss, and insertion through the embedded UART communication lock step safety measure state machine (LSSM). The {{max_num}} self verifies all communication within the message payload to simplify the software development on the host microcontroller.Additionally, the MAX17851 monitors the host microcontroller to detect any failures. In the event of a communication failure with the host, the MAX17851 first tries to automatically recover communication. If unsuccessful, it assumes control. The MAX17851 can then optionally re-configure the daisy chain network that allows battery conditions to continue to be monitored. This allows for continued safe system operation. Lastly, the MAX17851 provides contactor signalling in the event that the battery conditions fall outside of the programmed range, putting the complete system into a failsafe state.ApplicationsBattery Management Systems (BMS)Electric and Hybrid Electric Vehicles (EV/HEV)Energy Storage Systems (ESS)

The MAX17853 is a flexible data-acquisition system for the management of high-voltage and low-voltage battery modules. The system can measure 14 cell voltages and a combination of six temperatures or system voltage measurements with fully redundant measurement engines in 263µs, or perform all inputs solely with the ADC measurement engine in 156µs. There are 14 internal balancing switches rated for > 300mA for cell-balancing current, each supporting extensive built-in diagnostics. Up to 32 devices can be daisy-chained to manage 448 cells and monitor 192 temperatures.Cell and bus-bar voltages ranging from -2.5V to +5V are measured differentially over a 65V common-mode range, with a typical accuracy of 1mV (3.6V cell, 25°C).If oversampling is enabled, up to 128 measurements per channel can be averaged internally with 14-bit resolution and combined with digital post-processing IIR filtering for increased noise immunity. The system can shut itself down in the event of a thermal overload by measuring its own die temperature.For robust communications, the system uses a Maxim battery-management UART or SPI protocol, and is optimized to support a reduced feature set of internal diagnostics and rapid-alert communication through both embedded communication and hardware-alert interfaces to support ASIL D and FMEA requirements.ApplicationsBattery-Backup Systems (UPS)Battery-Powered ToolsElectric BikesElectric Vehicles (EVs)High-Voltage Battery StacksHybrid Electric Vehicles (HEVs)Super-Cap Systems

The MAX17854 is a flexible data-acquisition system for the management of high-voltage and low-voltage battery modules. The system can measure 14 cell voltages and a combination of six temperatures or system voltage measurements with fully redundant measurement engines in 162µs, or perform all inputs solely with the ADC measurement engine in 99µs. There are 14 internal balancing switches rated for >300mA for cell-balancing current, each supporting extensive built-in diagnostics. Up to 32 devices can be daisy-chained to manage 448 cells and monitor 192 temperatures.Cell and bus-bar voltages ranging from -2.5V to +5V are measured differentially over a 65V common-mode range, with a typical accuracy of 100µV. If oversampling is enabled, up to 128 measurements per channel can be averaged internally with 14-bit resolution and combined with digital post-processing IIR filtering for increased noise immunity. The system can shut itself down in the event of a thermal overload by measuring its own die temperature.The system uses Analog Devices' battery-management UART protocol for robust communications and supports an I2C master interface for external device control, and is optimized to support a reduced feature set of internal diagnostics and rapid-alert communication through both embedded communication and hardware-alert interfaces to support ASIL D and FMEA requirements.ApplicationsBattery-Backup Systems (UPS)Battery-Powered ToolsElectric BikesElectric Vehicles (EVs)High-Voltage Battery StacksHybrid Electric Vehicles (HEVs)Super-Cap Systems