Communication ICs IrDA infrared communication IC (SIR / ASK compatible) RPM-800CB Series The RPM-800CB series is an infrared communication IC that is compatible with the IrDA1.0 and ASK communication systems. The infrared LED, PIN photodiode, and modulator circuit are combined onto a single package, and connection to a UART requires just three lines (transmit, receive, and control). Applications Cellular phones, pagers, PDA, PHS, notebook PCs, and printers Features 1) Infrared emitting, receiver, and modulator / demodulator on the chip. 2) Switchable modes. IrDA mode ASK mode Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 544 3) 2.4 to 115.2kbps communication rate. 4) Built-in powerdown mode 5) Power supply voltage input range 2.7 to 5.5V. Communication ICs RPM-800CB Series Block diagram Pin descriptions 545 Communication ICs Input / output circuits 546 RPM-800CB Series Communication ICs RPM-800CB Series Electrical characteristics (unless otherwise noted, Ta = 25C and VDD = 3V) 547 Communication ICs RPM-800CB Series Circuit operation IrDA format ASK format Register function Control character format As shown in the Fig.3, the control character is made up of four address bits, four data bits, a start bit and a stop bit. 548 Communication ICs RPM-800CB Series Explanation of the registers Register table 4) Mode register Reset 0000 IrDA 0001 ASK 1) Control register 1 Reset 0 0 0 0 0 When VDD = 5V and ASK is used, set the LED drive control register to M or L. 5) Control register 2 0 0 0 ECHO 0 No control character echo back 1 Control character echo back ECAN 0 Does not cancel reception of transmitted (self emitted) data 1 Cancels reception of transmitted (self emitted) data RXEN 0 Receiver OFF 1 Receiver ON TXEN 0 Transmitter OFF 1 Transmitter ON Reset LOAD 0 1 0 0 0 0 Do not load the baud rate counter value Load the baud rate counter value * The load bit automatically returns to 0 after the counter value is loaded. 2) LED drive current control register Reset 0 0 0 0 0 1 0 0000 H 0001 M 0010 L 3) Baud rate register Reset 0000 0001 0010 0011 0100 0101 0110 0 2.4Kbps 4.8Kbps 9.6Kbps 19.2Kbps 38.4Kbps 57.6Kbps 115.2Kbps (when the clock is 3.6864MHz) 549 Communication ICs Timing chart 1) Reset operation 2) Register write 3) Echo back 550 RPM-800CB Series Communication ICs RPM-800CB Series 4) Transmit 5) Receive 6) Echo cancel 7) Power down 551 Communication ICs Application example Operation notes (1) Use a shield when there is a possibility of influence due to electromagnetic noise. (2) The baud rate is set to 9600bps after the power is applied, or the IC is reset. (3) The setting in the baud rate register becomes effective when the LOAD bit of control register 2 is set to 1. (4) Avoid using together with strong light sources. (5) We recommend to use crystal oscillator. 552 RPM-800CB Series Communication ICs RPM-800CB Series Electrical characteristics curves External dimensions (Units: mm) 553