Multiple LTC6804s can be interconnected over long distances and operated simultaneously, using Linear Technology's proprietary 2-wire isoSPI™ interface. Integrated into every LTC6804, the isoSPI interface provides high RF noise immunity up to 1Mbps and up to 100 meters of cable, using only twisted pair. Two communication options are available: with the LTC6804-1, multiple devices are connected in a daisy chain with one host processor connection for all devices; with the LTC6804-2, multiple devices are connected in parallel to the host processor with each device individually addressed.
The LTC6804 was designed to minimize power consumption, especially during long-term storage where battery drain is unacceptable. In sleep mode, the LTC6804 draws less than 4µA from the batteries. General purpose I/O pins are available to monitor analog signals, such as current and temperature, and can be captured simultaneously with the cell voltage measurements. Additional features include passive balancing for each cell with a programmable balancing timer for up to 2 hours, even when the LTC6804 is in sleep mode. The LTC6804 interfaces with external I2C devices such as temperature sensors, ADCs, DACs and EEPROM. Local EEPROM can be used to store serialization and calibration data, enabling modular systems.
Designed to surpass the environmental, reliability and safety demands of automotive and industrial applications, the LTC6804 is fully specified for operation from -40°C to 125°C. It has been engineered for ISO 26262 (ASIL) compliant systems and a full set of self-tests ensure that there are no latent fault conditions. To accomplish this, the chip includes a redundant voltage reference, extensive logic test circuitry, open wire detection capability, a watchdog timer and packet error checking on the serial interface.
Along with the LTC6804, Linear Technology is introducing the LTC6820 isoSPI transceiver. The LTC6820 enables bidirectional transmission of the Serial Peripheral Interface bus (SPI) across an isolated barrier up to 100 meters. With the LTC6820, the SPI data is encoded into a differential signal, which is then