TPIC2801

The TPIC2801 octal intelligent-power switch is a monolithic BIDFET† integrated circuit designed to sink currents up to 1 A at 30 V simultaneously at each of eight driver outputs under serial input data control. Status of the individual driver outputs is available in serial data format. The TPIC2801 driver outputs have overcurrent limiting and out-of-saturation voltage protection features. Applications of TPIC2801 include driving solenoids, relays, dc motors, lamps, and other medium-current or high-voltage loads.

The device contains an 8-bit serial-in, parallel-out shift register that feeds an 8-bit parallel latch, which independently controls each of the eight Y-output drivers.

Data of TPIC2801 is entered into the device serially via the serial input (SI) and goes directly into the lowest bit (0) of the shift register. Using proper timing signals, the input data is passed to the corresponding output latch and output driver. A logic-high bit at SI turns the corresponding output driver (Yn)off. A logic-low bit at SI turns the corresponding output driver on. Serial data is transferred into SI on the high-to-low transition of serial clock (SCLK) input in 8-bit bytes with data for the Y7 output (most significant bit) first and data for Y0 output (least significant bit) last. Both SI and SCLK are active when serial input-output enable (SIOE) input is low and are disabled when SIOE is high.

Each TPIC2801 driver output is monitored by a voltage comparator that compares the Y-output voltage level with an internal out-of-saturation threshold voltage reference level. The logic state of the comparator output is dependent upon whether the Y output is greater or smaller than the reference voltage level. An activated driver output is unlatched and turned off when the output voltage exceeds the out-of-saturation threshold voltage level except when the internal unlatch enable is low and disabled. The high-to-low transition of SIOE transfers the logic state of the comparator output to the shift register.