Communication ICs Panel interface BU8315S / BU8315F The BU8315S and BU8315F are LED drivers with a flashing function. They can be connected in series to panel PCBs in equipment such as telephones, facsimile machines, and copying machines, and to microcomputers of main PCBs, and significantly reduce the amount of wiring required. Applications Sets with operation panels, such as telephones, facsimile machines, and copying machines Features 1) LED interface (14-bit serial in / parallel out). 2) Built-in LED automatic flashing function. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 289 Communication ICs Block diagram Pin descriptions 290 BU8315S / BU8315F Communication ICs BU8315S / BU8315F Input / output circuits Electrical characteristics (unless otherwise noted, Ta = 25C, VDD = 3 5.5V) 291 Communication ICs Serial data input timing Measurement circuits 292 BU8315S / BU8315F Communication ICs BU8315S / BU8315F Circuit operation (1) LED control command data format (for serial data, the MSB is first) (2) Shifts in flashing pattern based on LED control commands (example of data input) (3) Example of serial input of LED control command 293 Communication ICs Operation notes (1) When the power supply is turned on, the contents of the register are unstable, so the RST pin should be set to LOW and a reset initiated. Electrical characteristic curves External dimensions (Units: mm) 294 BU8315S / BU8315F (2) The maximum LED output per bit is 20mA, so that the maximum LED output for a total of 14 bits is 140mA.