Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors SIR Endec for IrDA® Applications Integrated Interface Circuit FEATURES • Pulse shaping function according IrDA SIR physical layer • Directly interfaces the SIR transceiver to a RS232 port 20810 • QFN-20 - package, 4 mm x 4 mm x 0.75 mm DESCRIPTION • Low operating current The TOIM5232 endec IC provides proper pulse shaping for the SIR IrDA front end infrared transceivers as of the 4000-series. • Programmable baud clock generator (1200 Hz to 115.2 kHz), 13 baud rates For transmitting the TOIM5232 shortens the RS232 output signal to IrDA compatible electrical pulses to drive the infrared transmitter. In the receive mode, the TOIM5232 stretches the received infrared pulses to the proper bit width depending on the operating bit rate. The IrDA bit rate varies from 2.4 kbit/s to 115.2 kbit/s. • For 2.7 V to 3.6 V operation voltage, 5 V tolerant inputs The TOIM5232 is using a crystal clock 3.6864 MHz (< 7.5 MHz) for its pulse stretching and shortening. The clock is generated by the internal oscillator. An external clock can be used, too. The TOIM5232 is programmable to operate from 1200 bit/s to 115.2 kbit/s by the communication software through the RS232 port. The output pulses are software programmable as either 1.627 μs or 3/16 of bit time. The typical power consumption is very low with about 10 mW in operational state and in the order of a few microwatts in standby mode. TOIM5232 in the tiny QFN-20 package is the space-minimized version of TOIM4232. ULC Technology: High performance gate array package using multiple metal layer CMOS technology featuring sub-micron channel lengths (0.35 μm). • 3/16 bit pulse duration or 1.627 μs pulse selectable • Qualified for lead (Pb)-free and Sn/Pb solder processing (MSL3) • Material categorization: for definitions of compliance please see www.vishay.com/doc?99912 PARTS TABLE PART TOIM5232-TR3 DESCRIPTION QTY/REEL SIR Endec for IrDA application 6000 pcs PRODUCT SUMMARY PART NUMBER TOIM5232 DATA RATE (kbit/s) DIMENSIONS HxLxW (mm x mm x mm) LINK DISTANCE (m) OPERATING VOLTAGE (V) IDLE SUPPLY CURRENT (mA) 1.2 to 115 4 x 4 x 0.75 - 2.7 to 3.6 2 Rev. 1.4, 15-Jan-15 Document Number: 81749 1 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors BLOCK DIAGRAM VCC TD_IR TD_232 Endec RD_232 RD_IR TD_LED Baud generator BR/D RD_LED S1 S2 Logic RESET VCC_SD Oscillator GND X1 X2 18079 PIN ASSIGNMENT AND DESCRIPTION PIN NUMBER SYMBOL DISCRIPTION Received signal data output of stretched signal to the RS232 RXD line (using level converter). Input of the signal to be transmitted from the RS232 port TXD line (passing the level converter). This pin can be used to shut down a transceiver (e.g., TFDx4xxx). Output polarity: Inverted RESET input. I/O ACTIVE O High I High O Low 1 RD_232 2 TD_232 3 VCC_SD 4 X1 Crystal input clock, 3.6864 MHz nominal for 9.6 kbit/s default setting. Input for external clock (1). Option: 7.3728 MHz for 19.2 kbit/s default operation. I 5 X2 Crystal (1) I 7 GND Ground in common with the RS232 port and IrDA transceiver ground 9 TD_LED Transmit LED indicator driver. Use 180 current limiting resistor in series to LED to connect to VCC (VCC = 3.3 V). O Low 10 RD_LED Receive LED indicator driver. Use 180 current limiting resistor in series to LED to connect to VCC (VCC = 3.3 V). O Low 12 S1 O Low 13 S2 O Low 14 TD_IR User programmable bit. Can be used to turn on/off a front-end infrared transceiver (e.g., an infrared module at the adapter front). User programmable bit. Can be used to turn on/off a front-end infrared transceiver (e.g., an infrared module at the adapter back). Data output of shortened signal to the infrared transceiver. O High 16 RD_IR Data input from the infrared transceiver, min. pulse duration 1.63 μs (2) I Low 17 VCC Supply voltage I RESET Resets all internal registers. Initially must be high (“1”) to reset internal registers. When high, the TOIM5232 sets the IrDA default bit rate of 9600 bit/s, sets pulse width to 1.627 μs. The VCC_SD output is simply an inverted reset signal which allows shutdown of a TFDx4x00 transceiver when applying the reset signal to the TOIM5232. When using devices with external SD like TFDU4101, the reset line can be used directly as shutdown signal. RESET pin can be controlled by either the RTS or DTR line through RS232 level converter. Minimum hold time for resetting is 1 μs. Disables the oscillator when active. 18 19 BR/D 6, 8, 11, 15, 20 High Baud rate control/data BR/D = 0, data communication mode: RS232 TXD data line is connected (via a level shifter) to TD_232 input pin. The TXD - signal is appropriately shortened and applied to the output TD_IR, driving the TXD input of the IR transceiver. The RXD line of the transceiver is connected to the RD_IR input. This signal is stretched to the correct bit length according to the programmed bit rate and is routed to the RS232 RXD line at the RD_232 pin. BR/D = 1, programming mode: Data received from the RS232 port is interpreted as control word. The control word programs the baud rate width will be effective as soon as BR/D return to low. NC Notes (1) Crystal should be connected as shown in the block diagram or in the recommended application circuit. Connect a 100 k resistor from pin 4 to pin 5 and from pin 4 and pin 5 a 22 pF capacitor to ground, respectively. When an external clock is available connect it to pin 4 leaving pin 5 open. The external resistor of 100 k is used to accelerate the start of the oscillation after reset or power-on. The value depends on the “Q” of the resonator. With low Q resonators no resistor is needed. The start-up time of the oscillator is between 30 μs (with piezo resonators) and above 2 ms with high Q quartzes. (2) This condition is fulfilled with all Vishay IR transceivers. Rev. 1.4, 15-Jan-15 Document Number: 81749 2 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL MIN. Supply voltage VCC Input voltage Output voltage IOUT Output sinking current TYP. MAX. UNIT -0.5 3.6 V -0.5 5.5 V -0.5 VCC + 0.5 8 TJ Junction temperature Tamb -25 Storage temperature Tstg -25 Soldering temperature Tsldr Ambient temperature (operating) NOTES All pins V All pins mA All pins 125 °C 85 °C 85 °C 260 °C DC CHARACTERISTICS PARAMETER TEST CONDITIONS Operating voltage SYMBOL MIN. TYP. MAX. UNIT VCC 2.7 3.3 3.6 V VIH 2 VCC = 3.3 V ± 5 %, operating temperature = - 25 °C to + 85 °C Input high voltage Inputs tolerate levels as high as 5.5 V maximum. All inputs are Schmitt trigger inputs Input low voltage V 0.8 VIL Input Schmitt trigger hysteresis 0.6 Vhyst Input leakage no pull-up/down V V VIN = VCC or GND IL -10 IOH = - 2 mA VOH 2 IOH = - 0.5 mA VOH 2.4 IOL = + 2 mA VOL 0.4 V Consumption current standby Inputs grounded, no output load VCC = 3.3 V, T = 25 °C ISB 1 μA Consumption current dynamic Inputs grounded, no output load VCC = 3.3 V, T = 25 °C ICC Output high voltage Output low voltage OPERATION DESCRIPTION The block diagram shows a typical example of an RS232 port interface. The TOIM5232 connects to an RS232 level converter on one side, and an infrared transceiver on the other. The internal TOIM5232 baud rate generator can be software controlled. When BR/D = 0, the TOIM5232 interprets the channels TD_232 to TD_IR and RD_IR to RD_232 as data channels. On the other hand, whenever BR/D = 1, the TOIM5232 interprets TD_232 as control word for setting the baud rate. The baud rate can be programmed to operate from 1200 bit/s to 115.2 kbit/s. As RS232 level converter, EIA232 or MAX232 or equivalent are recommended. When using the TOIM5232 directly connected to an UART it is compatible to 5 V TTL and 3.3 V CMOS logic. Typical external resistors and capacitors are needed as shown in the TFDU4...,TFBS4...-series references. The output pulse duration can also be programmed, see chapter “operation description”. It is strongly recommended using 1.627 μs output pulses to save battery power. As frequency determining component a Vishay XT49M crystal is recommended, when no external clock is available. ±1 10 μA V V 2 mA We strongly recommend not to use this 3/16 mode because 3/16 pulse length at lower bit rates consumes more power than the shorter pulse. At a data rate of 9600 bit/s, the ratio of power consumption of both modes is a factor of 12 (!) PROGRAMMING THE TOIM5232 For correct data rate dependent timing the TOIM5232 is using a built-in baud rate generator. This is used when no external clock is not available as in RS232 IR-dongle applications. For programming the BR/D pin has to be set active, BR/D = 1. In this case the TOIM5232 interprets the 7 LSBs at the TD_232 input as a control word. The operating baud rate will change to its supposedly new baud rate when the BR/D returns back to low (“0”) set the UART to 8 bit, no parity, 1 stop bit. Rev. 1.4, 15-Jan-15 Document Number: 81749 3 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors CONTROL BYTE (8 BIT) BAUD RATE SELECT WORDS FIRST CHARACTER X S2 S1 SECOND CHARACTER S0 B3 B2 B1 B3 B2 B1 B0 2nd CHAR BAUD RATE 0 0 0 0 0 115.2 kHz 0 0 0 1 1 57.6 kHz 0 0 1 0 2 38.4 kHz 0 0 1 1 3 19.2 kHz 0 1 0 0 4 14.4 kHz 0 1 0 1 5 12.8 kHz 0 1 1 0 6 9.6 kHz 0 1 1 1 7 7.2 kHz 1 0 0 0 8 4.8 kHz 1 0 0 1 9 3.6 kHz 1 0 1 0 A 2.4 kHz 1 0 1 1 B 1.8 kHz 1 1 0 0 C 1.2 kHz B0 LSB X: do not care S1, S2: user programmable bit to program the outputs S1 and S2 S0: IrDA pulse select S0 = (1): 1.627 μs output pulses S0 = (0): 3/16 bit time pulses, not recommended B0 to B3: baud rate select words according following table. Example: To set TOIM5232 at COM2 port (2F8) to 9600 bit/s with 3/16 bit time pulse duration send to the TOIM5232 in programming mode in e.g. “basic” OUT &H2F8, (&H6) For same port, 9600 bit/s and 1.627 μs pulse duration send OUT &H2F8, (&H16) For additionally activating S1 send OUT &H2F8, (&H36) Note IrDA standard only supports 2.4 kbit/s, 9.6 kbit/s, 19.2 kbit/s, 57.6 kbit/s, and 115.2 kbit/s (3.6864 MHz clock). Doubling the baud rates is allowed by doubling the clock frequency. SOFTWARE FOR THE TOIM4232 AND TOIM5232 UART PROGRAMMING For proper operation, the RS232 must be programmed (using 8 bit, 1 stop, no parity) to send a two character control word, YZ. The control word YZ is composed of two characters, written in hexadecimal, in format: YZ. The transfer rate for programming must be identical with the formerly programmed data rate, or after resetting the TOIM5232, the default rate of 9600 bit/s is used. STEP. RESET BR/D TD_UART RD_UART RD_IR TD_IR DESCRIPTION AND COMMENTS 1 High X X X X X Resets all internal registers. Resets to IrDA default data rate of 9600 bit/s 2 Low X X X X X Wait at least 2 ms, to allow start-up of internal clock. When external clock is used: wait at least 7 μs. 3 Low High X X X X Wait at least 7 μs. TOIM5232 now is set to the control word programming mode High YZ with Y = 1: 1.627 μs Y=0 3/16 bit length X Sending the control word YZ. Examples: Send “1Z” if 1.627 μs pulses are intended to be used. Otherwise send “0Z” for 3/16 bit period pulses. “Y6” keeps the 9.6 kbit/s data rate. Z = 0 sets to 115.2 kbit/s, see programming table. Wait at least 1 μs for hold-time. Data With BR/D = 0, TOIM5232 is in the data communication mode. Both RESET and BR/D must be kept low (“0”) during data transmission. Reprogramming to a new data rate can be resumed by restarting from step 3. The UART itself also must set to the correct data rate (1). 4 5 Low Low Low Data X Data X Data Note • It is recommended reading the I/O buffer after transmission waiting the specified latency allowance. That avoids receiving unexpected data from pulses stochastically generated by many transceivers during the latency time. (1) For programming the UART, refer to e.g., National Semiconductors datasheet of PC 16550 UART. Rev. 1.4, 15-Jan-15 Document Number: 81749 4 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors RECOMMENDED APPLICATION CIRCUIT FOR TOIM5232 R3 MAX3232CSE 1 C+ VCC 18 4 C1- V+ U1 C2+ V- 2 19 6 1 + C6 + C5 + C7 + C4 5 C2- GND 2 15 3 4 11 10 12 9 T1IN T2IN R1OUT R2OUT T1OUT T2OUT R1IN R2IN 14 7 13 8 5 7 VCC RESET BR/D U2 RD_IR RD_232 TD_IR TD_232 S2 VCC_SD S1 X1 NC X2 RD_LED GND TD_LED 17 C10 2 + 3 TFDU4301 TOIM5232 16 + C3 R4 optional C11 16 4 14 6 13 8 IRED Cathode RXD IRED Anode TXD U3 Vcc1 SD GND Vlog 1 3 5 7 12 *) 10 9 J1 *) NC: 6, 8, 11, 15, 20 1 6 2 7 3 8 4 9 5 RXD RTS (BR/D) TXD R1 DTR (RESET) Y1 Vcc Z2 J2 CON9 External input 3.6 V max. 1 2 Z1 C1 R2 + C2 C8 CON2 C9 20799 Application circuit using TFDU4301 with integrated level shifter MAX3232CSE. When used directly with 3 V - or 5 V - logic, the level shifter can be omitted. RECOMMENDED APPLICATION CIRCUIT COMPONENTS COMPONENT RECOMMENDED VALUE VISHAY PART NUMBER 1. C1 100 nF VJ 1206 Y 104 J XXMT 2. C2 10 μF, 16 V 293D 106X9 016B 2T 3. C3 100 nF VJ 1206 Y 104 J XXMT 4. C4 100 nF VJ 1206 Y 104 J XXMT 5. C5 100 nF VJ 1206 Y 104 J XXMT 6. C6 100 nF VJ 1206 Y 104 J XXMT 7. C7 1 μF, 16 V 293D 105X9 016A 2T 8. C8 22 pF VJ 1206 A 220 J XAMT VJ 1206 A 220 J XAMT 9. C9 22 pF 10. C10 6.8 μF, 16 V (optional) 293D 685X9 016B 2T 11. C11 100 nF VJ 1206 Y 104 J XXMT 12. Z1 3.6 V BZT55C3V6 13. Z2 3.6 V BZT55C3V6 14. R1 5.6 k CRCW-1206-5601-F-RT1 15. R2 100 k CRCW-1206-1003-F-RT1 16. R3 47 CRCW-1206-47R0-F-RT1 17. R4 27 (for reduced current only) CRCW-1206-27R0-F-RT1 18. Y1 3.686400 MHz XT49S - 20 - 3.686400M 19. U1 MAX 3232CSE MAXIM MAX 3232CSE 20. U2 TOIM5232 21. U3 TFDU4301 22. J1 9 pin - connector Cannon 23. J2 Power connector Philmore PHI 211B Rev. 1.4, 15-Jan-15 Document Number: 81749 5 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors PACKAGE DIMENSIONS in millimeters Recommanded footprint 2 0.5 0.3 4.3 0.55 Pin 1 ID 0.3 0.55 4.3 20797 REEL DIMENSIONS in millimeters Drawing-No.: 9.800-5090.01-4 Issue: 1; 29.11.05 14017 TAPE WIDTH (mm) A MAX. (mm) N (mm) W1 MIN. (mm) W2 MAX. (mm) W3 MIN. (mm) W3 MAX. (mm) 12 330 50 12.4 22.4 11.9 15.4 Rev. 1.4, 15-Jan-15 Document Number: 81749 6 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors TAPE DIMENSIONS in millimeters 20798 Rev. 1.4, 15-Jan-15 Document Number: 81749 7 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors TOIM4232 (TOIM5232) ENCODER - DECODER INTERFACE PROGRAMMING AND DATA TRANSMISSION Operation and programming of the TOIM4232 and TOIM5232 interface devices are described below. Figure 1 shows the basic circuit design with 3 blocks: the RS232 to 3 V logic level shifter, the encoder/decoder (endec) circuit and the transceiver to build a dongle for RS232 IrDA extension. U1 is the level shifter to convert the RS232 logic levels to unipolar 3 V logic; U2 is the encoder/decoder Interface (endec) converting the NRZ - RS232 logic to IrDA RZI - logic. The transceiver U3 transmits and receives IrDA-compliant optical signals. R3 MAX3232 1 C+ 16 1(18) + C3 VCC 3 4 RESET U1 C1- V+ C2+ V- 2 2(19) 6 3(1) + C4 TOIM4232 (TOIM5232) + 5 C2- GND C6 + C5 + C7 4(2) 15 5(3) U2 BR/D RD_232 Vcc RD_IR TD_IR TD_232 S2 Vcc_SD S1 T1IN T2IN R1OUT R2OUT T1OUT T2OUT R1IN R2IN X1 14 7 13 8 7(5) 8(7) 15(16) C10 2 + 4 14(14) 6 13(13) 8 IRED Cathode RXD Vcc1 GND 12(12) 6(4) 11 10 12 9 16(17) X2 GND NC RD_LED TD_LED 11 *) R4 optional TFDU4101 TFDU4301 C11 IRED Anode U3 TXD SD TFDU4101:NC . TFDU4300:Vlog 1 3 5 7 This line not used fot TFDU4101 10(10) 9(9) J1 *) (6), (8), (11), (15), (20) 1 6 2 7 3 8 4 9 5 RXD RTS (BR/D) TXD R1 DTR (RESET) Y1 Vcc Z2 CON9 External input 3.6V max. J2 1 2 C1 CON2 R2 + C2 C8 C9 21046 Fig. 1 - Circuit Diagram of the Demo Board CIRCUIT DESCRIPTION PROGRAMMING THE ENDEC This circuit demonstrates the operation of an SIR IrDA transceiver module. The transceiver U3 (e.g., as shown the TFDU4101 or TFDU4301 or any other) converts the digital electrical input signal to an optical output signal to be transmitted, receives the optical signal, and converts these to electrical digital signals. While the IrDA physical layer protocol transmits only the “0” represented by a pulse with a “Return to Zero Inverted (RZI)” logic, the RS232 protocol needs a “No Return to Zero (NRZ)” representation. This decoding/encoding process is done by U2, an interface circuit stretching the received pulses and shortening the pulses to be transmitted according to the IrDA physical layer conditions. U1 interfaces the RS232 logic bipolar levels to the 3 V logic of the Endec U2. The board is connected by CON9 to the RS232 port (of a computer or other equipment. The basic IrDA transmission speed is 9600 bit/s. This is the default state of the Endec in power-on condition. Also, activating the reset line at pin 1 (18) will set the device to this basic state. Note: The first pin number refers to TOIM4232; the second number in brackets refers to TOIM5232. The crystal Y1 controls the timing of the Endec as a clock reference. The outputs S1 and S2 are programmable outputs for control operations and the outputs RD_LED and TD_LED can drive LEDs for indicating data flow. For decoding data rates other than the default, the endec is to be programmed to set the internal counters and timers. To switch the endec from the data transfer mode to the bit rate programming mode, the input BR/D, pin 2 (19) is set active high (BR/D = “1”). In this case the TOIM5232 interprets the 7 LSBs at the TD_232 input as a control word. The operating bit rate will change to its supposedly new rate when the BR/D returns back to low (“0”). Set the UART to 8 bit, no parity, 1 stop bit. The control byte consists of 8 bit after the start bit (STA, which is “0”). Keep in mind that the order is LSB first, MSB last. The diagram in figure 2 shows the programming byte “0-1010-1100” in the order STA, B0, B1, B2, B3, S0, S1, S2, X. This order is from right to left in table 1. B0 is sent first as LSB (see figure 2). The four least significant bits are responsible for the data rate according to table 2 while the four higher bits are for setting the IrDA pulse duration (S0), and the two outputs of the endec S1 and S2. Bit 8 is not used. Rev. 1.4, 15-Jan-15 Document Number: 81749 8 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors TABLE 1 - CONTROL BYTE (8 BIT) FIRST CHARACTER X MSB S2 S1 S0 SECOND CHARACTER B3 B2 B1 STA B0 LSB 0 Example 0 0 1 1 0 1 0 1 0 In the oscilloscope that will be shown in the reserved order with LSB first, see figure 2. STA 0 FIRST CHARACTER B0 LSB B1 B2 B3 SECOND CHARACTER S0 S1 S2 1-> 2-> X MSB Example 0 1 0 1 0 1 1 0 0 Note X: do not care S1, S2: user-programmable bit to program the outputs S1 and S2. In the example, S1 is set active, and S2 is inactive. S0: IrDA pulse select S0 = (1): 1.627 µs output S0 = (0): 3/16 bit time pulses, not recommended B0 to B3: baud rate select words according to the following table below. TABLE 2 - TRANSMISSION RATE SELECT WORDS B3 B2 B1 B1 HEX BIT RATE 0 0 0 0 0 115.2 kHz 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 1 1 1 0 0 0 0 1 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 2 3 4 5 6 7 8 9 A B C 57.6 kHz 38.4 kHz 19.2 kHz 14.4 kHz 12.8 kHz 9.6 kHz 7.2 kHz 4.8 kHz 3.6 kHz 2.4 kHz 1.8 kHz 1.2 kHz Notes Bold: See example IrDA standard only supports 2.4 kbit/s, 9.6 kbit/s, 19.2 kbit/s, 57.6 kbit/s, and 115.2 kbit/s (3.6864 MHz clock). Doubling the baud rates is permissible by doubling the clock frequency. In figure 2 the programming sequence is shown for a bit rate of 12.8 kbit/s. 1) Ch1: BR/D; pin 2, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TD_232; pin 4; programming sequence 21038 Fig. 2 - Programming sequence for setting the endec to a bit rate of 12.8 kbit/s. After setting BR/D high (Ch1), the programming sequence with the control byte (Ch2) is applied to TD_232, pin 4. 1-> STA 1 0 1 0 0 1 0 0 2-> 1) Ch1: BR/D, pin 2, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TD_232, pin 4; programming sequence 21030 Fig. 3 - Programming sequence for setting the endec to a bit rate of 12.8 kbit/s as in figure 2 but with a 3/16 bit pulse duration (S0 = “0”). Example 0 MSB 0 1 0 0 1 0 1 0 LSB STA When correctly programmed, the endec shortens the pulse to be transmitted from the full bit duration to either 3/16 of the bit length or to 1.627 μs (which is 3/16 of the 115.2 kbit/s bit duration). For power saving, the short pulse is recommended. The received optical pulse shows in case of most of the Vishay SIR transceivers, constant pulse duration. The endec stretches that to the correct bit time according the bit rate setting. This is shown in the following chapters. Rev. 1.4, 15-Jan-15 Document Number: 81749 9 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors TRANSMIT (TXD) CHANNEL Figure 4 shows the transmission in the default mode. For data transfer, the endec is set to that mode by BR/D = “0”. In the examples “6” is always transmitted (binary “00000110”). The “0” is represented in the IrDA protocol by an optical pulse. Also here the LSB is transmitted first after the start bit. “1” is not transmitted. 1-> 2-> 3-> STA 0 1-> 1 1 0 0 0 0 1) Ch1: TD_232, pin 4, vertical scale: 2 V/div., horizontal scale: 20 µs/div. 2) Ch2: TD_IR, pin 14; 1.6 µs pulse duration 3) Ch3: TD_LED, pin 9 0 21033 2-> T 3-> 1) Ch1: TD_232 inp. pin 4, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TD_IR, pin 14; 1.6 µs pulse duration 3) Ch3: TD_LED, pin 9 Fig. 6 - Data transmission with the setting 115.2 kbit/s, 1.627 μs pulse duration. By definition, the pulse duration of 1.627 μs is identical to the 3/16-bit pulse width. RECEIVE (RXD) CHANNEL In the default 9600 bit/s mode the signals will look like those shown in figure 7 and figure 8. 21031 Fig. 4 - Data transmission with 9.6 kbit/s,1.627 μs pulse duration Channel 1 shows the signal from the RS232 port already converted to 3 V logic by U1. The Endec encodes that signal to the RZI IrDA format where a “0” is represented by a pulse. That is the trace of channel 2. This output is connected the TXD input of the transceiver and this signal is transmitted as optical output signal. Channel 3 is the signal for an indicator lamp connected to the TD_LED driver output. Use 180 serial resistor to supply voltage for limiting the current through the LED (not shown in the circuit diagram). When using the (not recommended) 3/16-bit pulse width the oscillogram looks like figure 5. 1-> 2-> 3-> 1) Ch1: TOIM4232; RD_IR, pin 15, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TOIM4232; RD_232, pin 3 3) Ch3: TOIM4232; RD_LED, pin 10 21034 Fig. 7 - Data reception with the setting 9.6 kbit/s. Short RXD pulse 1-> 1-> 2-> 2-> 3-> 1) Ch1: TD_232, pin 4, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TD_IR, pin 14; 3/16 bit pulse duration 3) Ch3: TD_LED, pin 9 21032 Fig. 5 - Data transmission with the setting 9.6 kbit/s, 3/16 bit pulse duration (19.5 μs) The transmission with the highest SIR bit rate of 115.2 bit/s looks like what is shown in figure 6. However, the horizontal time scale is different. 3-> 1) Ch1: TOIM4232; RD_IR, pin 15, vertical scale: 2 V/div., horizontal scale: 200 µs/div. 2) Ch2: TOIM4232; RD_232, pin 3 3) Ch3: TOIM4232; RD_LED, pin 10 21035 Fig. 8 - Data reception with the setting 9.6 kbit/s. Same as in figure 7, extended pulse duration The endec stretches the received pulses of about 2 µs duration from the transceiver output (figure 7, channel 1) independent of the pulse duration to the full bit width generating NRZ code (channel 2). Channel 3 is the signal for the indicator lamp. As shown in figure 8, channels 2 and 3, the final NRZ signal is identical to figure 7, even when longer pulses are received. In the 115.2 kbit/s mode the signals will look like those shown Rev. 1.4, 15-Jan-15 Document Number: 81749 10 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Vishay Semiconductors in figure 7 and figure 8. The difference is just the time scale. It also indicates the delay of the decoded channel 2 vs. channel 1. Channel 1 shows the signal from the transceiver. In this case it is TFDU4101 with unsymmetrical switching times. TFDU4101 is using tri-state outputs with push-pull drivers with symmetrical pulse switching times. All Vishay IrDA transceivers exhibit constant output pulse duration in SIR mode of about 2 µs independent of the duration of the optical input pulse. 1-> 2-> 3-> 1) Ch1: TOIM4232; RD_IR, pin 15, vertical scale: 2 V/div., horizontal scale: 10 µs/div. 2) Ch2: TOIM4232; RD_232, pin 3 3) Ch3: TOIM4232; RD_LED, pin 10 21036 Fig. 9 - Data reception with the setting 115.2 kbit/s “ECHO-ON” OR “ECHO-OFF” AND “LATENCY ALLOWANCE” handle that. The easiest way is to clean up the receiver channel after sending the last pulse and waiting for the latency period. Later, many transceivers that block the RXD channel during transmission and during the latency period were released to the market. This behavior is called “Echo-off”. Unfortunately, some OEMs like to use the signal from the RXD channel during transmission, as a self-test feature for testing the device on board without using the optical domain. Therefore, many new devices have been developed to echo the TXD input signal at the RXD output. Such behavior is called “echo-on”. Some software developed for “echo-off” applications is not able to receive and understand the signals from echo-on devices correctly. Therefore, an add-on to the circuit shown in figure 1 was generated to suppress the echo from the receiver during transmission. This modification is shown in figure 10. During transmission, the signal from the RXD output of the transceiver is just gated by the transmit signal, (see the oscilloscope picture in figure 11). During transmission, the receiver inside a transceiver package is exposed to very strong irradiance of the transmitter, which causes overload conditions in the receiver circuit. After transmission it takes some time to recover from this condition and return to the specified sensitivity. During this time the receiver is in an unstable condition, and at the output unexpected signals may arise. Also, during transmission under overload conditions the receiver may show signals on the RXD channel that are similar to or identical with the transmitted signal. To get clean or at least specified conditions for the receive channel during transmission, different terms were defined. The time to allow the receiver to recover from overload conditions is the latency allowance or shorter, just the specified latency. This is covered by the IrDA physical layer specification and is a maximum of 10 ms. IrDA specifies shorter negotiable latency. In SIR the minimum is 0.5 ms. This includes software latency. Transceivers are in general below 0.3 ms. In the first generations, some suppliers did not care for the behavior of the RXD output of the transceivers during transmission and latency time. The software is able to R4 optional R3 C11 MAX3232 1 C+ VCC + C3 3 1 U1 C1- V+ C2+ V- 2 2 6 3 + C6 + C5 + C7 5 4 15 C2- 5 6 11 10 12 9 T1IN T2IN R1OUT R2OUT T1OUT T2OUT R1IN R2IN R5 8 14 7 13 8 7 8 RESET U2 Vcc BR/D RD_IR RD_232 TD_IR TD_232 S2 Vcc_SD S1 X1 NC X2 RD_LED GND TD_LED 16 15 1 14 5 + U4 COM_1 NO_2 COM_2 Cathode 2 4 6 6 11 10 8 7 INS1 INS2 DG2039 9 J1 1 6 2 7 3 8 4 9 5 2 D NC_1 13 12 TFDU4301 TFDU4101 C10 4 V+ + C4 TOIM4232*) 16 RXD Vcc1 GND Anode U3 TXD SD . 1 3 5 7 3 This line not used forTFDU4101 Pin7: TFDU4101:NC TFDU4300:Vlog *) For TOIM5232 pinning, see figure 1. RXD RTS (BR/D) TXD R1 DTR (RESET) Y1 Vcc J2 CON9 External input 3.6V max. 1 2 CON2 Z1 C1 + C2 R2 Z2 C8 C9 21047 Fig. 10 - Demo Board Circuit with Echo-Suppression to be Used for Echo-On and Echo-Off Transceivers. Rev. 1.4, 15-Jan-15 Document Number: 81749 11 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Not for New Designs TOIM5232 www.vishay.com Additionally, with the programmable output S1 of the endec the echo suppression feature can be switched on and off for testing. The default mode is echo-off. To enable the echo, S1 is to be set inactive/low. (See the chapter for programming the TOIM4232, TOIM5232). The oscilloscope diagrams are shown in figure 11. Channel 2 shows the echo signal on the RXD output of the TFDU4101 transceiver during transmission. Channel 1 is the signal used for gating the path from the transceiver RXD output to the endec. On channel 3 the signal at the input of the endec is shown with a residual signal. Finally, the output to the RS232 port, RD_232, is clean without any noise signal. Vishay Semiconductors 1-> 2-> 3-> 4-> 1) Ch1: TOIM4232; TD_232, pin 4, vertical scale: 2 V/div., horizontal scale: 20 µs/div. 2) Ch2: TFDU4101; RXD, pin 4 (IR) 3) Ch3: TOIM4232; RD_IR, pin 15 4) Ch4: TOIM4232; RD_232, pin 3 21037 Fig. 11 - Echo-Suppression Rev. 1.4, 15-Jan-15 Document Number: 81749 12 For technical questions within your region: [email protected], [email protected], [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Legal Disclaimer Notice www.vishay.com Vishay Disclaimer ALL PRODUCT, PRODUCT SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE WITHOUT NOTICE TO IMPROVE RELIABILITY, FUNCTION OR DESIGN OR OTHERWISE. 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We confirm that all the products identified as being compliant to IEC 61249-2-21 conform to JEDEC JS709A standards. Revision: 02-Oct-12 1 Document Number: 91000