 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
TOIM4232 Datasheet(数据表) 4 Page - Vishay Siliconix |
|
||||||||||||||||||||||||||||||
TOIM4232 Datasheet(HTML) 4 Page - Vishay Siliconix |
|
|
4 page 
www.vishay.com 4 Document Number 82546 Rev. 1.5, 06-Jun-06 TOIM4232 Vishay Semiconductors Operation Description Figure 2 shows a typical example of an RS232 port interface. The TOIM4232 connects to an RS232 level converter on one side, and an infrared transceiver on the other. The internal TOIM4232 baud rate generator can be software controlled. When BR/D = 0, the TOIM4232 interprets the chan- nels TD_232 to TD_IR and RD_IR to RD_232 as data channels. On the other hand, whenever BR/D = 1, the TOIM4232 interprets TD_232 as Control Word for setting the Baud rate. The Baud rate can be pro- grammed 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 TOIM4232 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 TFDx4xxx references. The output pulse duration can also be programmed, see chapter "Operation Description". It is strongly rec- ommended using 1.627 µs output pulses to save bat- tery power. As frequency determining component a Vishay XT49M Crystal is recommended, when no external clock is available. We strongly recommend not to use this 3/16 mode because 3/16 pulse length at lower bit rates con- sumes more power than the shorter pulse. At a data rate of 9600 bit/s, the ratio of power con- sumption of both modes is a factor of 12 (!). Programming the TOIM4232 For correct, data rate dependent timing the TOIM4232 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 TOIM4232 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. Control Byte (8 bit) X: Do not care S1, S2: User programmble bit to program the outputs S1 and S2 S0: Irda pulse select S0 = (1): 1.627 µs pulses S0 = (0): 3/16 bit time pulses, not recommended B0 .. B3: Baud rate select words Example: To set TOIM4232 at COM2 port (2F8) to 9600 bit/s with 3/16 bit time pulse duration send to the TOIM4232 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) Input leakage no pull-up/down VIN = VDD or GND IL - 10 ± 1 10 μA Output HIGH voltage IOH = - 2.0 mA VOH 2.0 V IOH = - 0.5 mA VOH 2.4 V Output LOW voltage IOL = + 2.0 mA VOL 0.4 V Consumption current standby inputs grounded, no output load VCC = 3.3 V, T = 25 °C ISB 1µA Consumption current dynamic inputs grounded, no output load VCC = 3.3 V, T = 25 °C ICC 2mA Parameter Test Conditions Symbol Min Typ. Max Unit First Character Second Character X S2 S1 S0 B3 B2 B1 B0 LSB |
Chinese▼
English
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
